BGP filtering with route-maps

[snofrar]

Hi,

I have a BGP neighbour with a route-map to filter incoming updates, this route-map only has one permit statement with a ACL match clause, but I've realized that this ACL doesn't exist.

I thought it should block everythig but I can see all the networks from this neighbour, is this a normal behaviour ?

[thisisshanky]

Yes thats correct. The ACL needs to be in place for filtering to happen.

[wkumari]

Yup, this is normal behavior. All ACLs have an implicit deny at the end, but only if they exist!

This means you can do

no access-list 101

int f0/0

ip access 101 in

and nothing will happen, but as soon as you add the first line to 101 you will start denying everything (other than what you explicitly allowed in the first line.)

Warren.

[Harold Ritter]

If the ACL is not configured all routes are accepted indeed. Make sure you do configure an ACL.

Hope this helps,

[snofrar]

Thank you all for the information, I thought that even the ACL doesn't exist there was an implicit deny.

The configuration is being arranged and all is in place, thank you