Routing

Hi

My scenario is like this. My AS (65000) is connected to other AS like this. My AS (65000)->AS1(65001)->AS2(65002)->AS3 (Any no)->  and so on.

In My AS I want to filter the routes coming from AS1 but generated in AS3 or next AS no (not in AS1 and AS2). What would be the regular expression for this.

Thanks

How about having multiple terms? Define , as-path AS1 and AS2 for routes originated from AS1 and AS2

as-path AS1 ".* 65001"

as-path AS2 ".* 65002"

then reject routes matching as-path AS1 and AS2

term reject-AS {

  from {

     as-path AS1

     as-path AS2

  }

 then reject

}

You can match another AS-Path which will accept the routes generated from AS3 and above..

Thanks. I tested if we accept the routes originating from the AS using these regular expression then in second term we can change the attributes of other routes.

Hello,

I am doing research and come across this, and would like to seek for advice or idea about my case. I have as-path from Cisco XR config as below and what is the equivalent on Junos?

as-path-set CUST1
     ios-regex '_12345_',
     ios-regex '_12345$',
     ios-regex '_12367$'
end-set

Thanks in advance,

https://www.juniper.net/documentation/en_US/junos/topics/usage-guidelines/policy-configuring-as-path-regular-expressions-to-use-as-routing-policy-match-conditions.html

Hi,

Because 3 different lines of Cisco config is 3 different condition, So I dont think single line of "as-path" is equal. Do you think as-path-group is the correct one? Would you mind provide an example?

Appreciate your input,

show policy-options
as-path-group CUST1 {
as-path 1 ".* 12345 .*";
as-path 2 ".* 2345";
as-path 3 ".* 12367";
}

Awesome, thank you very much for your input.