Hi all, Hoping somebody can offer a suggestion here. We run a number of sites with a single fibre back to our DC, we have a virtualised redundant core network there and want to take the fibre vlans to each core router for termination rather than just one so that we have redundancy in the core. We have a /30 going from each site to each core router and OSPF running at both ends. By using OSPF interface costs in the DC we can preference the traffic flow through one core router or another, but when there is only one interface at the remote site what's the options for preferencing that traffic flow coming back using OSPF ? Any suggestions would be appreciated. Thanks Paul
Hi Paul, If you are using a unique VLAN for each OSPF adjacency, then on the site routers you can specify the cost per-VLAN. However if you have them all on the 1 VLAN, or directly on the interface, then I'm not aware of any way to adjust the cost to prefer a specific path. If you use something like BGP, there are a multitude of ways to prefer particular routes. Regards, Philip Loenneker | Network Engineer | TasmaNet -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Paul Julian Sent: Wednesday, 30 January 2019 10:38 AM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Subject: [MT-AU Public] OSPF with backup paths Hi all, Hoping somebody can offer a suggestion here. We run a number of sites with a single fibre back to our DC, we have a virtualised redundant core network there and want to take the fibre vlans to each core router for termination rather than just one so that we have redundancy in the core. We have a /30 going from each site to each core router and OSPF running at both ends. By using OSPF interface costs in the DC we can preference the traffic flow through one core router or another, but when there is only one interface at the remote site what's the options for preferencing that traffic flow coming back using OSPF ? Any suggestions would be appreciated. Thanks Paul _______________________________________________ Public mailing list Public@talk.mikrotik.com.au http://talk.mikrotik.com.au/mailman/listinfo/public_talk.mikrotik.com.au
Thanks Philip, Yes unfortunately the B end is an access port only, no vlans, hence the limitations we are finding. We have toyed with the idea of using BGP but apart from this it's really not needed and just adds to complexity for us. Regards Paul -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Philip Loenneker Sent: Wednesday, 30 January 2019 10:57 AM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Subject: Re: [MT-AU Public] OSPF with backup paths Hi Paul, If you are using a unique VLAN for each OSPF adjacency, then on the site routers you can specify the cost per-VLAN. However if you have them all on the 1 VLAN, or directly on the interface, then I'm not aware of any way to adjust the cost to prefer a specific path. If you use something like BGP, there are a multitude of ways to prefer particular routes. Regards, Philip Loenneker | Network Engineer | TasmaNet -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Paul Julian Sent: Wednesday, 30 January 2019 10:38 AM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Subject: [MT-AU Public] OSPF with backup paths Hi all, Hoping somebody can offer a suggestion here. We run a number of sites with a single fibre back to our DC, we have a virtualised redundant core network there and want to take the fibre vlans to each core router for termination rather than just one so that we have redundancy in the core. We have a /30 going from each site to each core router and OSPF running at both ends. By using OSPF interface costs in the DC we can preference the traffic flow through one core router or another, but when there is only one interface at the remote site what's the options for preferencing that traffic flow coming back using OSPF ? Any suggestions would be appreciated. Thanks Paul _______________________________________________ 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 Paul, It all depends on how important those features are to you. BGP may offer other benefits to you. You may be able to use the OSPF Instance In/Out filter on the site router to change some value for routes learned... but I'm not sure how you would match the routes learned from a specific neighbour. I don't have an OSPF configuration set up at the moment that I would be happy to potentially break to test this :) Regards, Philip Loenneker | Network Engineer | TasmaNet -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Paul Julian Sent: Wednesday, 30 January 2019 11:00 AM To: 'MikroTik Australia Public List' <public@talk.mikrotik.com.au> Subject: Re: [MT-AU Public] OSPF with backup paths Thanks Philip, Yes unfortunately the B end is an access port only, no vlans, hence the limitations we are finding. We have toyed with the idea of using BGP but apart from this it's really not needed and just adds to complexity for us. Regards Paul -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Philip Loenneker Sent: Wednesday, 30 January 2019 10:57 AM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Subject: Re: [MT-AU Public] OSPF with backup paths Hi Paul, If you are using a unique VLAN for each OSPF adjacency, then on the site routers you can specify the cost per-VLAN. However if you have them all on the 1 VLAN, or directly on the interface, then I'm not aware of any way to adjust the cost to prefer a specific path. If you use something like BGP, there are a multitude of ways to prefer particular routes. Regards, Philip Loenneker | Network Engineer | TasmaNet -----Original Message----- From: Public <public-bounces@talk.mikrotik.com.au> On Behalf Of Paul Julian Sent: Wednesday, 30 January 2019 10:38 AM To: MikroTik Australia Public List <public@talk.mikrotik.com.au> Subject: [MT-AU Public] OSPF with backup paths Hi all, Hoping somebody can offer a suggestion here. We run a number of sites with a single fibre back to our DC, we have a virtualised redundant core network there and want to take the fibre vlans to each core router for termination rather than just one so that we have redundancy in the core. We have a /30 going from each site to each core router and OSPF running at both ends. By using OSPF interface costs in the DC we can preference the traffic flow through one core router or another, but when there is only one interface at the remote site what's the options for preferencing that traffic flow coming back using OSPF ? Any suggestions would be appreciated. Thanks Paul _______________________________________________ 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
participants (2)
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Paul Julian -
Philip Loenneker