Re: using bgpd and ospfd
On 10/30/07, Henning Brauer <[EMAIL PROTECTED]> wrote: > > * Tony Sarendal <[EMAIL PROTECTED]> [2007-10-30 11:25]: > > On 10/30/07, Henning Brauer <[EMAIL PROTECTED]> wrote: > > > > > > * Tony Sarendal <[EMAIL PROTECTED]> [2007-10-30 02:28]: > > > > bgp rib and fib look out of sync. > > > > Any ideas why it behaves this way ? > > > > > > > > It seems like the networks that only exist in bgp fail to re-route > when > > > I > > > > take > > > > down a core router that is the current bgp-nexthop. > > > > > > lookslike there is a case we miss listening to the routing socket, or > > > there is sth in the message that makes us skip it. > > > can you run "route monitor" on the misbehaving machine while causing > > > the change and send me the output (no need to spam the list with that > > > tho)? > > > > > > > > Will do. > > > > So running a setup where ospfd and bgpd carries the same prefixes should > > work ? > > oh. the same ones. that is a bit iffy right now. That was the answer I was looking for =) No worries, I will adapt the live design I'm implementing as I want it working well on 4.2. I can either make sure ospfd and bgpd and don't carry the same prefixes, which is possibly in this particulare case, or I can go bgp-only. I'm most likely going bgp-only, hot-potato routing is something I want. If there is any testing I can do to assist please let me know, otherwise I'll just continue to play with it. It is my form of mediation to clear my mind from work. /Tony
Re: using bgpd and ospfd
* Tony Sarendal <[EMAIL PROTECTED]> [2007-10-30 11:25]: > On 10/30/07, Henning Brauer <[EMAIL PROTECTED]> wrote: > > > > * Tony Sarendal <[EMAIL PROTECTED]> [2007-10-30 02:28]: > > > bgp rib and fib look out of sync. > > > Any ideas why it behaves this way ? > > > > > > It seems like the networks that only exist in bgp fail to re-route when > > I > > > take > > > down a core router that is the current bgp-nexthop. > > > > lookslike there is a case we miss listening to the routing socket, or > > there is sth in the message that makes us skip it. > > can you run "route monitor" on the misbehaving machine while causing > > the change and send me the output (no need to spam the list with that > > tho)? > > > > Will do. > > So running a setup where ospfd and bgpd carries the same prefixes should > work ? oh. the same ones. that is a bit iffy right now. -- Henning Brauer, [EMAIL PROTECTED], [EMAIL PROTECTED] BS Web Services, http://bsws.de Full-Service ISP - Secure Hosting, Mail and DNS Services Dedicated Servers, Rootservers, Application Hosting - Hamburg & Amsterdam
Re: using bgpd and ospfd
On 2007/10/30 10:17, Tony Sarendal wrote: > So running a setup where ospfd and bgpd carries the same prefixes should > work ? I had problems with this, I think bgpd was stomping on the ospf route of my IX's /24, causing the routes from peers to fail nexthop validation on the other routers. I didn't get to the bottom of it so I just started filtering that /24 in bgpd but I don't think it's meant to do that. The routing table doesn't handle multiple routes with differing priorities, so the daemons must watch for updates on the routing socket and react to them, I guess this is somewhat delicate but I don't have a diff so I'll shut up (-:
Re: using bgpd and ospfd
On 10/30/07, Henning Brauer <[EMAIL PROTECTED]> wrote: > > * Tony Sarendal <[EMAIL PROTECTED]> [2007-10-30 02:28]: > > bgp rib and fib look out of sync. > > Any ideas why it behaves this way ? > > > > It seems like the networks that only exist in bgp fail to re-route when > I > > take > > down a core router that is the current bgp-nexthop. > > lookslike there is a case we miss listening to the routing socket, or > there is sth in the message that makes us skip it. > can you run "route monitor" on the misbehaving machine while causing > the change and send me the output (no need to spam the list with that > tho)? Will do. So running a setup where ospfd and bgpd carries the same prefixes should work ? In the lab setup both ospf and bgp carry the loopback and links, and all non-core prefixes are in bgp only. When I run bgp-only things work like a charm, except for a bit of funkiness with existing tcp-sessions to routers showing a bit of funky routing... /Tony
Re: using bgpd and ospfd
* Tony Sarendal <[EMAIL PROTECTED]> [2007-10-30 02:28]: > bgp rib and fib look out of sync. > Any ideas why it behaves this way ? > > It seems like the networks that only exist in bgp fail to re-route when I > take > down a core router that is the current bgp-nexthop. lookslike there is a case we miss listening to the routing socket, or there is sth in the message that makes us skip it. can you run "route monitor" on the misbehaving machine while causing the change and send me the output (no need to spam the list with that tho)? -- Henning Brauer, [EMAIL PROTECTED], [EMAIL PROTECTED] BS Web Services, http://bsws.de Full-Service ISP - Secure Hosting, Mail and DNS Services Dedicated Servers, Rootservers, Application Hosting - Hamburg & Amsterdam
using bgpd and ospfd
I set up a test network with bgpd/ospfd, a standard service provider design where ospf carries the network links and loopbacks and bgp carries everything, bgp routers doing nexthop self, core full mesh and access routers rr-clients of the two nearest core routers. I'm seeing some pretty odd behaviour that I haven't seen before when only using bgpd. Are there any know issues with using this kind of design with bgpd/ospfd ? Quick example: View from an access router at another prefix on the other side of the network ar1# route get 10.1.102.0 route to: 10.1.102.0 destination: 10.1.102.0 mask: 255.255.255.0 gateway: 172.16.1.6 interface: vlan602 if address: 172.16.1.5 flags: use hopcount mtuexpire 1470 0 0 0 ar1# bgpctl show fib 10.1.102.0 ... flags destination gateway *B10.1.102.0/24 172.16.1.6 ar1# bgpctl show rib 10.1.1.02.0 ... flags destination gateway lpref medaspath origin I*> 10.1.102.0/24 192.168.0.1 120 3010 i I*10.1.102.0/24 192.168.0.2 120 3010 i ar1# ospfctl show fib 192.168.0.1 flags: * = valid, O = OSPF, C = Connected, S = Static FLags Destination Nexthop *O 192.168.0.1/32 172.16.1.6 ar1# So far so good. I now shut down the core router 192.168.0.1 The moment I do that the connectivity dies, even though there is another path. ar1# route get 10.1.102.0 route to: 10.1.102.0 destination: 10.1.102.0 mask: 255.255.255.0 gateway: 172.16.1.6 interface: vlan602 if address: 172.16.1.5 flags: use hopcount mtuexpire 1646 0 0 0 ar1# bgpctl show fib 10.1.102.0 ... flags destination gateway *B10.1.102.0/24 172.16.1.6 ar1# bgpctl show rib 10.1.1.02.0 ... flags destination gateway lpref medaspath origin I*>10.1.102.0/24 192.168.0.2 120 3010 i ar1# ospfctl show fib 192.168.0.2 flags: * = valid, O = OSPF, C = Connected, S = Static FLags Destination Nexthop *O 192.168.0.2/32 172.16.1.2 ar1# bgp rib and fib look out of sync. Any ideas why it behaves this way ? It seems like the networks that only exist in bgp fail to re-route when I take down a core router that is the current bgp-nexthop. /Tony
