Remove a /26 network from a /24 public network but keep /24 at one site.

[Jas1066]

Hello All,

Getting a bit stuck on if this will work..

I have a network on a /24 public network (site B), i have removed a /26 (.64 to .128) and assigned this public range at another site (site B).

Okay the tricky bit..i have two WANs ISP on /30 from site A to site B via my two perimeter routers , with VRRP WAN tracking.  The ISP manages both  WANs and sends me a default gateway via BGP.  What is the best way to get to the /26 at site B, ISP cannot advertise a /26 for me at site A (as its not big enough mask). But they will advertise /26 via BGP  at site B.

Looking to setup a VPN (on firewall before the perimeter routers) between sites how do i reach the /26?? via a static route on the firewall via VRRP on the perimeter router and  static route on the perimeter via /30s WANs? Will i black hole any routes don't think so as i have VRRP WAN interface tracking but not sure if BGP peer fails does the WAN VRRP tracking fail (not a link failure)?

Thanks for any info

[Reza Sharifi · Accepted solution]

Hi,

I am not sure if that is going to work as .64 to .128 is in the middle of a /24 and it already being advertised from site-A.

HTH

[Jas1066]

Hi Reza,

Logically advertising /24 at site A and advertising /26 at site B.  In theory this should work ISP BGP cloud advertising a specific /26 pointing to site B less specific (/24) to site A.

Not seeing alternative options to get around this?

Thanks for any info