/31 Deployments for Point-to-Point links
Hey all, Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant? Thanks, Christopher Hawker
G'day! If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise... Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :) Cheers! Mike. ----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links Hey all, Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant? Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Hi, Pretty sure I recall reading on the Mikrotik Forums where someone else was trying this and could not get a /31 to work with BGP on mikrotik. Andrew -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Mike Everest via Public Sent: Monday, January 8, 2024 3:30 PM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au> Cc: mike@duxtel.com Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links G'day! If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise... Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :) Cheers! Mike. ----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links Hey all, Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant? Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Hi Andrew, That's what I don't get - from a general technological perspective there's no reason why it shouldn't work. If anything, it's only giving me a reason to start steering away from Mikrotik for anything other than aggregation and end-user CPE. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 18:43, Andrew Oakeley via Public < public@talk.mikrotik.com.au> wrote:
Hi,
Pretty sure I recall reading on the Mikrotik Forums where someone else was trying this and could not get a /31 to work with BGP on mikrotik.
Andrew
-----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Mike Everest via Public Sent: Monday, January 8, 2024 3:30 PM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au> Cc: mike@duxtel.com Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Hi, I don’t think mikrotik is RFC3021 compliant. So although you can beat a mikrotik into submission to get traffic to flow using a /31, I expect there are other bits to make it compliant that are missing. Not that I have actually read the RFC to know. Andrew From: Christopher Hawker <chris@thesysadmin.au> Sent: Monday, January 8, 2024 4:08 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Andrew Oakeley <andrew@oakeley.com.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hi Andrew, That's what I don't get - from a general technological perspective there's no reason why it shouldn't work. If anything, it's only giving me a reason to start steering away from Mikrotik for anything other than aggregation and end-user CPE. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 18:43, Andrew Oakeley via Public <public@talk.mikrotik.com.au<mailto:public@talk.mikrotik.com.au>> wrote: Hi, Pretty sure I recall reading on the Mikrotik Forums where someone else was trying this and could not get a /31 to work with BGP on mikrotik. Andrew -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au<mailto:public-bounces@talk.mikrotik.com.au>> On Behalf Of Mike Everest via Public Sent: Monday, January 8, 2024 3:30 PM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au<mailto:public@talk.mikrotik.com.au>> Cc: mike@duxtel.com<mailto:mike@duxtel.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links G'day! If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise... Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :) Cheers! Mike. ----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au<mailto:public-bounces@talk.mikrotik.com.au>> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au<mailto:public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au<mailto:chris@thesysadmin.au>> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links Hey all, Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant? Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au<mailto:Public@talk.mikrotik.com.au> http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au<mailto:Public@talk.mikrotik.com.au> http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au<mailto:Public@talk.mikrotik.com.au> http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
I believe I might have been too premature in jumping to the conclusion that Mikrotik isn't RFC3021 compliant. https://datatracker.ietf.org/doc/html/rfc3021 After having a look at it in a bit more detail, it appears that 3021 is about the ability to use /31 prefixes, not using them for BGP. Tiks can use /31 subnets for point-to-point links, just not for BGP by the looks of things. Still doesn't make sense though. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 19:28, Andrew Oakeley via Public < public@talk.mikrotik.com.au> wrote:
Hi,
I don’t think mikrotik is RFC3021 compliant. So although you can beat a mikrotik into submission to get traffic to flow using a /31, I expect there are other bits to make it compliant that are missing. Not that I have actually read the RFC to know.
Andrew
From: Christopher Hawker <chris@thesysadmin.au> Sent: Monday, January 8, 2024 4:08 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Andrew Oakeley <andrew@oakeley.com.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links
Hi Andrew,
That's what I don't get - from a general technological perspective there's no reason why it shouldn't work. If anything, it's only giving me a reason to start steering away from Mikrotik for anything other than aggregation and end-user CPE.
Regards, Christopher Hawker
On Mon, 8 Jan 2024 at 18:43, Andrew Oakeley via Public < public@talk.mikrotik.com.au<mailto:public@talk.mikrotik.com.au>> wrote: Hi,
Pretty sure I recall reading on the Mikrotik Forums where someone else was trying this and could not get a /31 to work with BGP on mikrotik.
Andrew
-----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au<mailto: public-bounces@talk.mikrotik.com.au>> On Behalf Of Mike Everest via Public Sent: Monday, January 8, 2024 3:30 PM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au<mailto: public@talk.mikrotik.com.au>> Cc: mike@duxtel.com<mailto:mike@duxtel.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au<mailto: public-bounces@talk.mikrotik.com.au>> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au<mailto:public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au<mailto:chris@thesysadmin.au>> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au<mailto:Public@talk.mikrotik.com.au> http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
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_______________________________________________ Public mailing list Public@talk.mikrotik.com.au<mailto:Public@talk.mikrotik.com.au> http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Hey Mike, Apologies, what I meant was that if I use a /30 subnet for the handoff the config works, however with a /31 it does not. We've got about 80 sessions (bilats, route servers and transit links) so enabling debug logging floods my core with about 1000 entries per second. Looking at the other router with the single session gives me nothing referencing the new session. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 18:30, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Good morning! OK, understood :-} I can say for sure that it's not a 'BGP protocol limitation' since I have exactly that setup running on our warehouse border router ( /31 ppp addressing on link to upstream bgp peer) and it has worked flawlessly since installation some time ago. But that one IS a RouterOSv6, so you could be seeing a v7 'idiosyncrasy' - if the issue persists, perhaps consider logging a support case with our help desk - they can run up a test to reproduce the problem and report to MT for comment. <rant> As a completely pedantic side rant, a lot of this talk about /31 network support is nothing more than an argument in semantics IMO. I'll probably open up a can of worms here, so if that happens, apologies for hijacking your thread :-} /31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet', as it is a way better description of what we are really working with and helps to dispel all those myths about how routerOS implements it poorly or partially or fudges it or whatever. It is what it is - a point to point addressing scheme. For "slash 31", it just so happens by fortune, coincidence or chance, that the addresses at each end of the ppp link happen to be adjacent and fit a /31 mask RANGE ; ) However <substitute your router platform name here> represents the addressing scheme in the admin/configuration interface is irrelevant, and whether it allows the user to actually enter an address in the form a.b.c/31 is unimportant - the underlying technical implementation will be the same. 😏 </rant> Cheers! Mike. -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 6:55 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hey Mike, Apologies, what I meant was that if I use a /30 subnet for the handoff the config works, however with a /31 it does not. We've got about 80 sessions (bilats, route servers and transit links) so enabling debug logging floods my core with about 1000 entries per second. Looking at the other router with the single session gives me nothing referencing the new session. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 18:30, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
On Tue, 2024-01-09 at 10:43 +1100, Mike Everest via Public wrote:
/31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet'
If we are going to get pedantic, let's call it by its One True Name, which is "prefix length". All prefix lengths[1] are subnets, all subnets are address ranges, but not all address ranges are subnets. It's subnets all the way down :-) Regards, K. [1] Oh alright, not zero then. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
😃 👍 -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Karl Auer via Public Sent: Tuesday, 9 January 2024 11:19 AM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Karl Auer <kauer@nullarbor.com.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links On Tue, 2024-01-09 at 10:43 +1100, Mike Everest via Public wrote:
/31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet'
If we are going to get pedantic, let's call it by its One True Name, which is "prefix length". All prefix lengths[1] are subnets, all subnets are address ranges, but not all address ranges are subnets. It's subnets all the way down :-) Regards, K. [1] Oh alright, not zero then. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160 _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Hmm, but if we're being pedantic wouldn't there also be 0 usable addresses in a /31 once network ID and broadcast have been reserved? On Tue, 9 Jan 2024, 10:36 am Karl Auer via Public, < public@talk.mikrotik.com.au> wrote:
On Tue, 2024-01-09 at 10:43 +1100, Mike Everest via Public wrote:
/31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet'
If we are going to get pedantic, let's call it by its One True Name, which is "prefix length".
All prefix lengths[1] are subnets, all subnets are address ranges, but not all address ranges are subnets.
It's subnets all the way down :-)
Regards, K.
[1] Oh alright, not zero then.
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
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.. deductions like that are exactly my point! ; ) Concepts like 'broadcast' are really only applicable to a broadcast network - a broadcast network two hosts do not make (I believe it is a yoda quote ; ) -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Tim Allingham via Public Sent: Tuesday, 9 January 2024 11:45 AM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Tim Allingham <tim@tasmanitservices.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hmm, but if we're being pedantic wouldn't there also be 0 usable addresses in a /31 once network ID and broadcast have been reserved? On Tue, 9 Jan 2024, 10:36 am Karl Auer via Public, < public@talk.mikrotik.com.au> wrote:
On Tue, 2024-01-09 at 10:43 +1100, Mike Everest via Public wrote:
/31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet'
If we are going to get pedantic, let's call it by its One True Name, which is "prefix length".
All prefix lengths[1] are subnets, all subnets are address ranges, but not all address ranges are subnets.
It's subnets all the way down :-)
Regards, K.
[1] Oh alright, not zero then.
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
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As Mike said, you don't need a broadcast address on a point-to-point link. As for the network, the first IP address in the/31 ***subnet*** would be used as the network. Still usable on a host. Regards, Christopher Hawker On Tue, 9 Jan 2024 at 11:45, Tim Allingham via Public < public@talk.mikrotik.com.au> wrote:
Hmm, but if we're being pedantic wouldn't there also be 0 usable addresses in a /31 once network ID and broadcast have been reserved?
On Tue, 9 Jan 2024, 10:36 am Karl Auer via Public, < public@talk.mikrotik.com.au> wrote:
On Tue, 2024-01-09 at 10:43 +1100, Mike Everest via Public wrote:
/31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet'
If we are going to get pedantic, let's call it by its One True Name, which is "prefix length".
All prefix lengths[1] are subnets, all subnets are address ranges, but not all address ranges are subnets.
It's subnets all the way down :-)
Regards, K.
[1] Oh alright, not zero then.
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
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On Tue, 2024-01-09 at 10:44 +1000, Tim Allingham via Public wrote:
Hmm, but if we're being pedantic wouldn't there also be 0 usable addresses in a /31 once network ID and broadcast have been reserved?
It's a subnet containing two addresses, both reserved. You can use the remaining addresses however you like :-) Or, since you know that you and old mate at the other end are by definition the only two nodes on this network, you could just agree to talk... IPv6 has RFC 6164 (and RFC 6547 explicitly consigns RFC 3627 to the dustbin of history). IPv4 has RFC 3021. Regards, K. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
Hi all, Figured I'd drop this one from the MikroTik docs here, as I hadn't seen it mentioned already: https://help.mikrotik.com/docs/display/ROS/Routing+Protocol+Overview#:~:text... Cheers, Matt On Tue, 9 Jan 2024 at 11:28, Karl Auer via Public < public@talk.mikrotik.com.au> wrote:
On Tue, 2024-01-09 at 10:44 +1000, Tim Allingham via Public wrote:
Hmm, but if we're being pedantic wouldn't there also be 0 usable addresses in a /31 once network ID and broadcast have been reserved?
It's a subnet containing two addresses, both reserved. You can use the remaining addresses however you like :-)
Or, since you know that you and old mate at the other end are by definition the only two nodes on this network, you could just agree to talk...
IPv6 has RFC 6164 (and RFC 6547 explicitly consigns RFC 3627 to the dustbin of history).
IPv4 has RFC 3021.
Regards, K.
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Good find Matt, Deliciously cryptic... Does it imply that routed traffic DOES work to even address only? And what exactly does it even mean - since this table is explicitly "Routing Protocol", does it tell us that the problem is in the routing protocol itself, or in the resulting routing table? 🤷♂️ Cheers! -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Matthew Kobayashi via Public Sent: Tuesday, 9 January 2024 1:00 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Matthew Kobayashi <matthew@kobayashi.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hi all, Figured I'd drop this one from the MikroTik docs here, as I hadn't seen it mentioned already: https://help.mikrotik.com/docs/display/ROS/Routing+Protocol+Overview#:~:text... Cheers, Matt On Tue, 9 Jan 2024 at 11:28, Karl Auer via Public < public@talk.mikrotik.com.au> wrote:
On Tue, 2024-01-09 at 10:44 +1000, Tim Allingham via Public wrote:
Hmm, but if we're being pedantic wouldn't there also be 0 usable addresses in a /31 once network ID and broadcast have been reserved?
It's a subnet containing two addresses, both reserved. You can use the remaining addresses however you like :-)
Or, since you know that you and old mate at the other end are by definition the only two nodes on this network, you could just agree to talk...
IPv6 has RFC 6164 (and RFC 6547 explicitly consigns RFC 3627 to the dustbin of history).
IPv4 has RFC 3021.
Regards, K.
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Hmmm, might be something to test... Setting up the upstream with the even address and the session set to listen, and the downstream with the odd address and the session set to connect. Regards, Christopher Hawker On Tue, 9 Jan 2024 at 15:39, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
Good find Matt,
Deliciously cryptic... Does it imply that routed traffic DOES work to even address only?
And what exactly does it even mean - since this table is explicitly "Routing Protocol", does it tell us that the problem is in the routing protocol itself, or in the resulting routing table? 🤷♂️
Cheers!
-----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Matthew Kobayashi via Public Sent: Tuesday, 9 January 2024 1:00 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Matthew Kobayashi <matthew@kobayashi.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links
Hi all,
Figured I'd drop this one from the MikroTik docs here, as I hadn't seen it mentioned already:
https://help.mikrotik.com/docs/display/ROS/Routing+Protocol+Overview#:~:text...
Cheers, Matt
On Tue, 9 Jan 2024 at 11:28, Karl Auer via Public < public@talk.mikrotik.com.au> wrote:
On Tue, 2024-01-09 at 10:44 +1000, Tim Allingham via Public wrote:
Hmm, but if we're being pedantic wouldn't there also be 0 usable addresses in a /31 once network ID and broadcast have been reserved?
It's a subnet containing two addresses, both reserved. You can use the remaining addresses however you like :-)
Or, since you know that you and old mate at the other end are by definition the only two nodes on this network, you could just agree to talk...
IPv6 has RFC 6164 (and RFC 6547 explicitly consigns RFC 3627 to the dustbin of history).
IPv4 has RFC 3021.
Regards, K.
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@nullarbor.com.au) work +61 2 64957435 http://www.nullarbor.com.au mobile +61 428 957160
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Coming back to the original topic: Just for my own curiosity, I just ran up a pair of routerOS7 devices (just an RB750G and a 760 that I found laying around) added '/31' addressing between them (10.1.1.1 and 10.1.1.2 just for laughs ; ) added bgp peer between them - it came up immediately. Using routerOS v7.13.1 which appears to be latest stable at the moment. So I think we can rule out routerOS v7 bug... unless it is specific to arm64 ?? Cheers! -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Mike Everest via Public Sent: Tuesday, 9 January 2024 10:44 AM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au> Cc: Mike Everest <mike@duxtel.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Good morning! OK, understood :-} I can say for sure that it's not a 'BGP protocol limitation' since I have exactly that setup running on our warehouse border router ( /31 ppp addressing on link to upstream bgp peer) and it has worked flawlessly since installation some time ago. But that one IS a RouterOSv6, so you could be seeing a v7 'idiosyncrasy' - if the issue persists, perhaps consider logging a support case with our help desk - they can run up a test to reproduce the problem and report to MT for comment. <rant> As a completely pedantic side rant, a lot of this talk about /31 network support is nothing more than an argument in semantics IMO. I'll probably open up a can of worms here, so if that happens, apologies for hijacking your thread :-} /31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet', as it is a way better description of what we are really working with and helps to dispel all those myths about how routerOS implements it poorly or partially or fudges it or whatever. It is what it is - a point to point addressing scheme. For "slash 31", it just so happens by fortune, coincidence or chance, that the addresses at each end of the ppp link happen to be adjacent and fit a /31 mask RANGE ; ) However <substitute your router platform name here> represents the addressing scheme in the admin/configuration interface is irrelevant, and whether it allows the user to actually enter an address in the form a.b.c/31 is unimportant - the underlying technical implementation will be the same. 😏 </rant> Cheers! Mike. -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 6:55 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hey Mike, Apologies, what I meant was that if I use a /30 subnet for the handoff the config works, however with a /31 it does not. We've got about 80 sessions (bilats, route servers and transit links) so enabling debug logging floods my core with about 1000 entries per second. Looking at the other router with the single session gives me nothing referencing the new session. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 18:30, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
We're on 7.13 and the 7.13.1 changelog doesn't list any changes to either BGP or IP, so it shouldn't be an issue related to 7.13 specifically. Perhaps it is an ARM64 bug, unless someone else is able to test it? Specifically CCR2004-1G-12S+2XS. @Mike could you use /routing/fantasy/ with ~1.2m routes to simulate a full table from transit and peering? Just thinking of ways to load the devices to possibly simulate what I'm doing. Regards, Christopher Hawker On Tue, 9 Jan 2024 at 11:56, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
Coming back to the original topic:
Just for my own curiosity, I just ran up a pair of routerOS7 devices (just an RB750G and a 760 that I found laying around) added '/31' addressing between them (10.1.1.1 and 10.1.1.2 just for laughs ; ) added bgp peer between them - it came up immediately.
Using routerOS v7.13.1 which appears to be latest stable at the moment.
So I think we can rule out routerOS v7 bug... unless it is specific to arm64 ??
Cheers!
-----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Mike Everest via Public Sent: Tuesday, 9 January 2024 10:44 AM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au> Cc: Mike Everest <mike@duxtel.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links
Good morning!
OK, understood :-}
I can say for sure that it's not a 'BGP protocol limitation' since I have exactly that setup running on our warehouse border router ( /31 ppp addressing on link to upstream bgp peer) and it has worked flawlessly since installation some time ago.
But that one IS a RouterOSv6, so you could be seeing a v7 'idiosyncrasy' - if the issue persists, perhaps consider logging a support case with our help desk - they can run up a test to reproduce the problem and report to MT for comment.
<rant> As a completely pedantic side rant, a lot of this talk about /31 network support is nothing more than an argument in semantics IMO.
I'll probably open up a can of worms here, so if that happens, apologies for hijacking your thread :-}
/31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet', as it is a way better description of what we are really working with and helps to dispel all those myths about how routerOS implements it poorly or partially or fudges it or whatever. It is what it is - a point to point addressing scheme. For "slash 31", it just so happens by fortune, coincidence or chance, that the addresses at each end of the ppp link happen to be adjacent and fit a /31 mask RANGE ; )
However <substitute your router platform name here> represents the addressing scheme in the admin/configuration interface is irrelevant, and whether it allows the user to actually enter an address in the form a.b.c/31 is unimportant - the underlying technical implementation will be the same.
😏 </rant>
Cheers!
Mike.
-----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 6:55 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey Mike,
Apologies, what I meant was that if I use a /30 subnet for the handoff the config works, however with a /31 it does not.
We've got about 80 sessions (bilats, route servers and transit links) so enabling debug logging floods my core with about 1000 entries per second. Looking at the other router with the single session gives me nothing referencing the new session.
Regards, Christopher Hawker
On Mon, 8 Jan 2024 at 18:30, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Hi Strictly .1 and .2 are not in the same /31 Would be .0 and .1, or .2 and .3 Regards Roger To: "'MikroTik Australia Public List'" <public@talk.mikrotik.com.au> Date sent: Tue, 9 Jan 2024 11:55:48 +1100 Organization: DuxTel Pty Ltd Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links From: Mike Everest via Public <public@talk.mikrotik.com.au> Send reply to: MikroTik Australia Public List <public@talk.mikrotik.com.au> Copies to: Mike Everest <mike@duxtel.com> [ Double-click this line for list subscription options ] Coming back to the original topic: Just for my own curiosity, I just ran up a pair of routerOS7 devices (just an RB750G and a 760 that I found laying around) added '/31' addressing between them (10.1.1.1 and 10.1.1.2 just for laughs ; ) added bgp peer between them - it came up immediately. Using routerOS v7.13.1 which appears to be latest stable at the moment. So I think we can rule out routerOS v7 bug... unless it is specific to arm64 ?? Cheers! -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Mike Everest via Public Sent: Tuesday, 9 January 2024 10:44 AM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au> Cc: Mike Everest <mike@duxtel.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Good morning! OK, understood :-} I can say for sure that it's not a 'BGP protocol limitation' since I have exactly that setup running on our warehouse border router ( /31 ppp addressing on link to upstream bgp peer) and it has worked flawlessly since installation some time ago. But that one IS a RouterOSv6, so you could be seeing a v7 'idiosyncrasy' - if the issue persists, perhaps consider logging a support case with our help desk - they can run up a test to reproduce the problem and report to MT for comment. <rant> As a completely pedantic side rant, a lot of this talk about /31 network support is nothing more than an argument in semantics IMO. I'll probably open up a can of worms here, so if that happens, apologies for hijacking your thread :-} /31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet', as it is a way better description of what we are really working with and helps to dispel all those myths about how routerOS implements it poorly or partially or fudges it or whatever. It is what it is - a point to point addressing scheme. For "slash 31", it just so happens by fortune, coincidence or chance, that the addresses at each end of the ppp link happen to be adjacent and fit a /31 mask RANGE ; ) However <substitute your router platform name here> represents the addressing scheme in the admin/configuration interface is irrelevant, and whether it allows the user to actually enter an address in the form a.b.c/31 is unimportant - the underlying technical implementation will be the same. </rant> Cheers! Mike. -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 6:55 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hey Mike, Apologies, what I meant was that if I use a /30 subnet for the handoff the config works, however with a /31 it does not. We've got about 80 sessions (bilats, route servers and transit links) so enabling debug logging floods my core with about 1000 entries per second. Looking at the other router with the single session gives me nothing referencing the new session. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 18:30, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.co m. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.co m. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au---------------------------- Roger Plant
As I suspect you guessed: thus my comment 'just for laughs' - you fell right into my trap Roger! : ) I was even going to try being even more mischievous, by putting 0.0.0.0 and 255.255.255.255 on each end - but that would have been too obvious ; ) Cheers!! -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Roger Plant via Public Sent: Tuesday, 9 January 2024 1:21 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Roger Plant <rplant@melbpc.org.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hi Strictly .1 and .2 are not in the same /31 Would be .0 and .1, or .2 and .3 Regards Roger To: "'MikroTik Australia Public List'" <public@talk.mikrotik.com.au> Date sent: Tue, 9 Jan 2024 11:55:48 +1100 Organization: DuxTel Pty Ltd Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links From: Mike Everest via Public <public@talk.mikrotik.com.au> Send reply to: MikroTik Australia Public List <public@talk.mikrotik.com.au> Copies to: Mike Everest <mike@duxtel.com> [ Double-click this line for list subscription options ] Coming back to the original topic: Just for my own curiosity, I just ran up a pair of routerOS7 devices (just an RB750G and a 760 that I found laying around) added '/31' addressing between them (10.1.1.1 and 10.1.1.2 just for laughs ; ) added bgp peer between them - it came up immediately. Using routerOS v7.13.1 which appears to be latest stable at the moment. So I think we can rule out routerOS v7 bug... unless it is specific to arm64 ?? Cheers! -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Mike Everest via Public Sent: Tuesday, 9 January 2024 10:44 AM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au> Cc: Mike Everest <mike@duxtel.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Good morning! OK, understood :-} I can say for sure that it's not a 'BGP protocol limitation' since I have exactly that setup running on our warehouse border router ( /31 ppp addressing on link to upstream bgp peer) and it has worked flawlessly since installation some time ago. But that one IS a RouterOSv6, so you could be seeing a v7 'idiosyncrasy' - if the issue persists, perhaps consider logging a support case with our help desk - they can run up a test to reproduce the problem and report to MT for comment. <rant> As a completely pedantic side rant, a lot of this talk about /31 network support is nothing more than an argument in semantics IMO. I'll probably open up a can of worms here, so if that happens, apologies for hijacking your thread :-} /31 is not really a 'subnet' anyway, in the sense that a subnet is really just a conceptual structure for a broadcast domain. More properly, I prefer to call /31 an 'address range' instead of 'subnet', as it is a way better description of what we are really working with and helps to dispel all those myths about how routerOS implements it poorly or partially or fudges it or whatever. It is what it is - a point to point addressing scheme. For "slash 31", it just so happens by fortune, coincidence or chance, that the addresses at each end of the ppp link happen to be adjacent and fit a /31 mask RANGE ; ) However <substitute your router platform name here> represents the addressing scheme in the admin/configuration interface is irrelevant, and whether it allows the user to actually enter an address in the form a.b.c/31 is unimportant - the underlying technical implementation will be the same. </rant> Cheers! Mike. -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 6:55 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links Hey Mike, Apologies, what I meant was that if I use a /30 subnet for the handoff the config works, however with a /31 it does not. We've got about 80 sessions (bilats, route servers and transit links) so enabling debug logging floods my core with about 1000 entries per second. Looking at the other router with the single session gives me nothing referencing the new session. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 18:30, Mike Everest via Public < public@talk.mikrotik.com.au> wrote:
G'day!
If the session doesn't establish, it won't have anything to do with the networks you are trying to advertise...
Do routerOS logs give you any clues? If not, try adding bgp debug to system logging :)
Cheers! Mike.
----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, 8 January 2024 5:33 PM To: public@talk.mikrotik.com.au Cc: Christopher Hawker <chris@thesysadmin.au> Subject: [MT-AU Public] /31 Deployments for Point-to-Point links
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.co m. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.co m. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au---------------------------- Roger Plant _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Can you setup a /32, which looks like a /31? (or is that what you have?) eg. address xx.34 network xx.35 Date sent: Mon, 8 Jan 2024 17:32:49 +1100 To: public@talk.mikrotik.com.au Subject: [MT-AU Public] /31 Deployments for Point-to-Point links From: Christopher Hawker via Public <public@talk.mikrotik.com.au> Send reply to: MikroTik Australia Public List <public@talk.mikrotik.com.au> Copies to: Christopher Hawker <chris@thesysadmin.au> [ Double-click this line for list subscription options ] Hey all, Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant? Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au---------------------------- Roger Plant
I tried doing that; adding /32 addresses to both ends then creating routes to the other address via the respective interfaces. No dice. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 19:20, Roger Plant via Public < public@talk.mikrotik.com.au> wrote:
Can you setup a /32, which looks like a /31? (or is that what you have?)
eg. address xx.34 network xx.35
Date sent: Mon, 8 Jan 2024 17:32:49 +1100 To: public@talk.mikrotik.com.au Subject: [MT-AU Public] /31 Deployments for Point-to-Point links From: Christopher Hawker via Public < public@talk.mikrotik.com.au> Send reply to: MikroTik Australia Public List < public@talk.mikrotik.com.au> Copies to: Christopher Hawker <chris@thesysadmin.au>
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Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au---------------------------- Roger Plant
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Adding the route won't work, the only way I've gotten a /31 to work is like Roger suggested... Say your subnet is 1.1.1.42/31 End A: Address: 1.1.1.42 Network: 1.1.1.43 End B: Address: 1.1.1.43 Network: 1.1.1.42 No routes added or needed. I've just been through the same exercise due to needing to conserve address space. In the end I wasn't comfortable with using /31s without full support (what else will break one day..?) So I've given the core and edge /32 loopbacks from our address space and used the 100.64.0.0/10 space for the links. -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Christopher Hawker via Public Sent: Monday, January 8, 2024 7:26 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Christopher Hawker <chris@thesysadmin.au> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links I tried doing that; adding /32 addresses to both ends then creating routes to the other address via the respective interfaces. No dice. Regards, Christopher Hawker On Mon, 8 Jan 2024 at 19:20, Roger Plant via Public < public@talk.mikrotik.com.au> wrote:
Can you setup a /32, which looks like a /31? (or is that what you have?)
eg. address xx.34 network xx.35
Date sent: Mon, 8 Jan 2024 17:32:49 +1100 To: public@talk.mikrotik.com.au Subject: [MT-AU Public] /31 Deployments for Point-to-Point links From: Christopher Hawker via Public < public@talk.mikrotik.com.au> Send reply to: MikroTik Australia Public List < public@talk.mikrotik.com.au> Copies to: Christopher Hawker <chris@thesysadmin.au>
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Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au---------------------------- Roger Plant
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
We’re running a BGP session on an CCR2004-1G-12S+2XS on 7.12.1 with the provider using /31 addressing: /ip address add address=x.x.x.167/31 interface=sfpplus1 network=x.x.x.166 It’s not 7.13 but I’m not seeing anything in the changelog post 7.12.1 relating to BGP. -Darryl
On 8 Jan 2024, at 5:32 pm, Christopher Hawker via Public <public@talk.mikrotik.com.au> wrote:
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Well now, that's new! I didn't know we can add addresses with the /31 network now : ) I had a quick play with that, and turns out that the network specifier isn't needed either - it will automatically figure out the other end - cool : ) Ah, but only when the address defined is the higher end, i.e: /ip address add address=10.1.1.167/31 interface=ether1 (result is correctly configured - adds with network=10.1.1.166) /ip address add address=10.1.1.166/31 interface=ether1 (result is incorrectly defined - also adds with network=10.1.1.166) I initially thought it might be related to the development report about odd numbered /31 address, but this problem is on the even numbered address 🤷♂️ A bit frightening that there is behavior like this in a production OS :-l Cheers,.. -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Darryl Ross via Public Sent: Tuesday, 9 January 2024 5:29 PM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Cc: Darryl Ross <darryl@afoyi.com> Subject: Re: [MT-AU Public] /31 Deployments for Point-to-Point links We’re running a BGP session on an CCR2004-1G-12S+2XS on 7.12.1 with the provider using /31 addressing: /ip address add address=x.x.x.167/31 interface=sfpplus1 network=x.x.x.166 It’s not 7.13 but I’m not seeing anything in the changelog post 7.12.1 relating to BGP. -Darryl
On 8 Jan 2024, at 5:32 pm, Christopher Hawker via Public <public@talk.mikrotik.com.au> wrote:
Hey all,
Trying to stand-up a BGP session between a CCR2004-1G-12S+2XS and a CCR2004-16G-2S+ using a /31 for the link. I'm able to ping across the CCR2004-16G-2S+ link no problem, however, the BGP session doesn't establish. I'm attempting to move an existing session from a /30 where it works in order to conserve IP space. Is there some skullduggery going on, or is 7.13 just not RFC3021-compliant?
Thanks, Christopher Hawker _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com. au
_______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
participants (10)
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Andrew Oakeley
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Christopher Hawker
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Darryl Ross
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Karl Auer
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Matthew Kobayashi
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Mike Everest
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mike@duxtel.com
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Roger Plant
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Tim Allingham
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Two Fat Monkeys - Dirk Bermingham