topic Re: Palo Alto BGP with AWS Transit Gateway. in General Topics

Palo Alto BGP with AWS Transit Gateway.

nson2139 — Tue, 03 Aug 2021 10:15:03 GMT

Team,

We have a BGP neighbor on our Palo Alto with a Transit Gateway in the AWS. This BGP is formed from our Site A to the AWS TGW.

Now, we want to form another BGP from our Site B to the AWS TGW.

Site A should be preferred always and we know we can do that using the AS-path-prepends.

However, one additional requirement is that both the sites should advertise only the RFC 1918 IP's and the default route that we have. How can we achieve that?

The off course we will prepend that from Site B.

Regards!!

Re: Palo Alto BGP with AWS Transit Gateway.

SebRupik — Tue, 03 Aug 2021 12:18:06 GMT

Hi there,

This is as simple as creating an redistribution policy explicitly listing the rfc1918 prefixes and configuring the BGP process to use it.

You can also use an export policy to adjust other prefix attributes to be sent to your peers, but since you are using the AS path prepend feature then you will already have this configured. The export policy can also be used as the method to select the rfc1918 prefixes you want to advertise.

cheers,

Seb.