Blocking broadcast of Default route via BGP

[gilfalko]

Hey,

This is my problem:

How do I block default route from being broadcast over BGP?

Thanks!

[Iescudero]

Hello!!

First a Prefix:

config router prefix-list edit "Blocked Default Route" set comments "Bloquea aprendizaje de rutas por BGP de la MPLS" config rule edit 1 set prefix 192.168.0.0 255.255.0.0 next end

Then a Route Map:

config router route-map edit "ROUTE_MAP_DEFAULT" config rule edit 1 set action deny set match-ip-address "Blocked Default Route" next end

And last, apply Route Map in your neighbour:

config router bgp set as 64XXX config neighbor edit "XXX.XXX.XXX.XXX" set remote-as 64XXX set route-map-in "ROUTE_MAP_DEFAULT" end

Maybe exist a better solution, but this one worked for me when i dont want to learn some routes.

Hope it helps.

[Iescudero]

Ups i made a mistake:

This is the right prefix for you:

config router prefix-list edit "Blocked Default Route" config rule edit 1 set prefix 0.0.0.0 0.0.0.0 next end

Cyas

[gilfalko]

This will block EVERYTHING, not just the default route,...

[Iescudero]

just add this to the prefix:

unset ge set le 32

and try again

[gilfalko]

same thing I'm afraid.

[emnoc]

try

In the mask   "set prefix 0.0.0.0 255.255.255.255" or "set prefix 0.0.0.0/0"

Ken

[gilfalko]

Well, I nailed it eventually :)

This was an ACCESS-LIST but there's a small "twist" sort of speak which is not mentioned in the Forti documents as usual.

config router access-list edit "Block_Def_Route" config rule edit 1 set action deny set exact-match enable next edit 2 set exact-match disable next end next end

config neighbor edit "10.40.15.1" set distribute-list-in "Block_Def_Route" set remote-as 6167 set route-map-out "Verizon_Prepend1" next edit "10.40.16.1" set distribute-list-in "Block_Def_Route" set remote-as 6167 set route-map-out "Verizon_Prepend" next end

Without adding the bolded text this would have never worked.

what it means is to allow everything else BUT what is being actioned as "denied"

[Iescudero]

Thanks for the info!