How do i setup a BGP inbound filter that allows only 1 AS

Alex_Samad — Fri, 11 Sep 2020 23:02:39 GMT

Been looking and googling and can't find it .

so I have created a BGP import filter.

attached to router group.

But the match ... "AS Path Regular Expression"

what do i put in there to limit it to 1 AS

Find it hard to believe somebody hasn't done this. Also the doco ... sigh

I'm thinking something like

^[^_]*$

might work . not even sure is pa regex is standards compliant

Re: How do i setup a BGP inbound filter that allows only 1 AS

Alex_Samad — Fri, 11 Sep 2020 23:09:21 GMT

Gave it a try

seems to work !