-----Original Message----- From: Public [mailto:public-bounces@talk.mikrotik.com.au] On Behalf Of Damien Gardner Jnr Sent: Monday, 13 April 2015 8:55 PM To: MikroTik Australia Public List Subject: [MT-AU Public] Passing default route through BGP?
Hi Guys,
Our primary upstream has had a couple of small periods of complete downtime the last couple of nights, which has given me the opportunity (lol) to test our failover with our other two upstreams.
Found an issue in that it looks like RouterOS doesn't pass default route through BGP?
I currently have one router setup per upstream, receives a default route
full feed (but we filter to only directly-connected (one AS hop) prefixes for each upstream)
I then run IBGP between all edge routers. And also run OSPF between the four edge routers, and the core router, to send a default route to the core.
My thinking was that OSPF will redistribute a default route on any edge router with an active default route (i.e. BGP is up and/or gateway IP is pingable) Which works ok, IF the upstream gateway goes down. If I remove the hardcoded default routes, then it works as expected, but leaves those routers uncontactable.
I had also been expecting that the default route from each upstream was being passed on via iBGP to the other routers - to the point that I had been setting localpref on each one based on their cost and available bandwidth.
On checking tonight, it seems that the 0.0.0.0/0 routes are NOT being propagated via IBGP?
I can set default-originate=if-installed, which sends a default route from one peer to another, but it is not the one being received on eBGP from the usptream, as the localpref is wrong. And if I set default-originate=if-installed on the other peer, that peer stops receiving that default route.
Has anyone tried this? It works fine on quagga and cisco, but doesn't appear to be working on mikrotik (which if it's correct, makes me glad I found it before I'd forked out on another three hardware routers to go alongside my CCR when it arrives back)
Thanks,
DG
--
Damien Gardner Jnr VK2TDG. Dip EE. GradIEAust rendrag@rendrag.net - http://www.rendrag.net/ -- We rode on the winds of the rising storm, We ran to the sounds of
Hi Damien, Are you sure it's not being filtered out somewhere? RouterOS definitely advertises default route when configured to do so (i.e. default-originate=if-installed) Of course you would also need to redistribute routes learned from other BGP too (i.e. instance has redistribute-other-bgp=yes set), but judging from your comments thus far, I guess you already know that :-} Does default route show up in "rout bgp ad pr"? Cheers! Mike. plus thunder.
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