guys we have two router (redundant WAN connection to same service provider). we have bunch of network in core using ospf (WAN router is config with OSPF LAN side) now there was requirement by customer that bunch the network together and advertise them in BGP however there was a special requirement that specif network shd take specific router for in-coming traffic
the solution was that we have done prepend and aggregate the routes in BGP
so we have done
agregation with /16 under BGP (no network command was used as router was getting all the routes from OSPF)
and then i have done two porefix list
perix list from ospf to bgp
prefix list from BGP (not to ospf but from service provider)
in prefix list in bgp i have allowed default route (on both routers) and some specific routes for network management
in prefix list from ospf to bgp i have put /16 networks for redistribution (so in future if they add oteh routes they shd not get propagated to WAN)
now in as-path prepend they wanted that 192.168.1.0/16 shd come from WAN router 1 and 126.96.36.199/16 shd take router 2.and if one router fails the other network shd take the same.
in redistribution from BGP i have done
redistribute bgp subnets and second command was default information originate under ospf.
now the customer is saying that they have routing loop and told us that we shd put filters on redistribution of BGP into ospf
All i am saying that we are only allowing default routerplus specific routes how come they see there own network
which is 192.168.1.0/16
he is saying that since we are redistributing BGP into ospf with command redistribute the router is redistribution all subnet in BGP routing table is it possible as i guess we are advertising those networks with aggregation how come bgp is again redistributing them again into ospf. I think that BGP shd be only redistributing routes which is learned by BGP not advertising by BGP...
Thanks ya it has a summary-only as i was aware of that....the main point is where i am confused....from service provider we are getting default route on both routers plys some specfic routes now we are redistributing them back in ospf so the million dollar question is will the router advertise back the routes to ospf (the routes which are learned from ospf and advertised in bgp) as under ospf we are using
redistribute bgp subnets
default information orginate
the customer enginer is saying that since the routes are in bgp table (as its redisttrbued from ospf to bgp) so when u r redistributing back it will forward the same routes with default route which i am not beleieving and thats why i am here
yes. It is very much possible as I understand you have OSPF neighborship within the customer network as well. best way to prevent it is by specifically tagging the routes being learnt and filter while redistributing.
1.) Just identify the routes learnt from customer and tag them with let's say 110.
2.) while doing redistribution on other router just filter them with route-map identifying tag 110.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.