Re: prevent transit AS

Hi,

You could use null as-path regular expression as filter in BGP export policy to announce only locally originated routes:

http://www.juniper.net/techpubs/en_US/junos16.1/topics/usage-guidelines/policy-configuring-as-path-regular-expressions-to-use-as-routing-policy-match-conditions.html

[edit policy-options]
null-as "()";
policy-statement only-my-routes {
  term just-my-as {
    from {
      protocol bgp;
      as-path null-as;
    }
    then accept;
  }
  term nothing-else {
    then reject;
  }
}

Cheers,

Ashvin