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BGP - Route advertising

I have two routers that has a static route configured for the LAN side which re-distributes via BGP to the WAN.

One of the routers does not have anything connected to LAN subnet/ interface. Other one is live.

Will this create a routing conflict in the network ?

Everyone's tags (5)
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Silver

BGP - Route advertising

Can you draw a topology? Are you saying both routers redistribute it via BGP but only one of them can actually reach that network? In that case there could be a black hole issue if traffic arrives on the "wrong" router.

Daniel Dib
CCIE #37149

Daniel Dib CCIE #37149 Please rate helpful posts.
New Member

This was tested and it is

This was tested and it is working as expected. 

Can configure the same LAN and have static route configured. As long as they both aren't active at the same time. 

New Member

BGP - Route advertising

Yes, there is an issue here.

why the secondary router is advertising the LAN routes while it doesn't have reachabiility to the LAN.

In case if you are planning to connect the LAN lter it is recomended to configure the static routes with the exit interface.

i.e Ip route x.x.x.x y.y.y.y [LAN interface] [next hop ip add]

Ahmed

New Member

BGP - Route advertising

@ Daniel - I will post a topolgy diagram soon.

@ Ahmed - The circuits being built side by side and turn old one off and use the new one. Same LAN used to minimize interruptions / downtime . So if the next hop is configured as the interface ID not the IP address, it won't cause a routing conflict ?

New Member

Re:BGP - Route advertising

Hi Arvind,

Are these two routers a part of LAN topology? If so then we can enable IBGP between them to resolve the routing issues.

A topology diagram will help in detail understanding, thanks.


Sent from Cisco Technical Support Android App

New Member

Re:BGP - Route advertising

Hi,

If the next hop is not reachable, then the static route won't be kept in the routing table, meaning it won't be advertised by that router. IBGP between them would fix the problem.

Regards,

Tudor

HelloIf nothing is connected

Hello

If nothing is connected to it and your advertsieng that a static through that interface which doesnt dosnt go anywhere then you could blackhole traffic !

I would sugggest take the static out if its not being used, no need to have ghost config when its isnt required.

 

res

Paul

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