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iBGP prefix problem
Why is that when I establish an iBGP relationship between R1 and R2 I cannot receive the routes originating from R4?
But when I establish an iBGP relationship between R1 and R3 then I see the prefixes in R1?
*R2 is peered with R3 and has the routes that I want installed int its routing table
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NetworkVeteran
Member Posts: 2,338 ■■■■■■■■□□
A router won't advertise routes it learns via iBGP to another iBGP neighbor.Why is that when I establish an iBGP relationship between R1 and R2 I cannot receive the routes originating from R4?
Because in that case the above rule doesn't apply.But when I establish an iBGP relationship between R1 and R3 then I see the prefixes in R1?
When in doubt, full-mesh your iBGP.
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Optionsmochaaddict
Member Posts: 42 ■■□□□□□□□□
Might also want to play with route reflectors or confederations to get around the iBGP full mesh requirement.
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Optionsvishaw1986
Member Posts: 40 ■■□□□□□□□□
In IBGP we need a fully mesh network , this a type of BGP split horizon route (for loop prevention )......
e.g
A
B
C , A is neighbor to B and B is neighbor to C
Now the route learn by B through A is not fwd to C and ViceVersa -
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mguy
Member Posts: 167 ■■■□□□□□□□
NetworkVeteran wrote: »A router won't advertise routes it learns via iBGP to another iBGP neighbor.
Because in that case the above rule doesn't apply.
When in doubt, full-mesh your iBGP.
So this means all iBGP peers must be peered with the edge router (the router with an eBGP connection).
Thanks for the rule -
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mattau
Member Posts: 218
if you want to use the general rule of ibgp peering like discussed, other wise make R2 a route reflector._____________________________________
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