Looking for best solution to migration new Internet link with BGP default route

[kay_kang]

Hi, 

We're planning to replace the existing Internet link with new Internet link.

Currently, default route is advertised from the existing ISP via EBGP.

And, we will run EBGP peering with new ISP and they will advertise default route as well.

I am thinking of using higher BGP weight value with the new Internet link and  keep the current default route as secondary for cutover Internet access(Outbound traffic).

For seamless and minimizing impact to Internet access, Is there any else recommendable way to migrate the new Internet link? 

[pgautam]

Hi @kay_kang 

Thank you for posting your query.

In you network scenario FortiGate will be receiving two default routes from both the eBGP ISP neighbors.

If BGP receives two default routes then unless you add any extra configuration it will use one of them.

In this case, it's a good idea to add a weight attribute to explicitly choose one of the routes over the other. 

Regards
Priyanka

- Have you found a solution? Then give your helper a "Kudos" and mark the solution