Choose BGP default route from one of the MPLS sites ignoring ISP default route

[Sandeep Verma]

Hi All,

I have 5 sites connected over MPLS-VPN. BGP is running as egp. 
All sites are ebgp with ISP

I have a default route being learnt from ISP at all sites. I want to advertise default route from one of the MPLS sites so that others can reach here for Internet, bypassing ISP default route.

I want to get this done without involving the Service Provider for any change, making use of BGP attributes and Route-map.

Can anyone provide some solution. is there is any .....or anyone having faced the same issue ..how did it go further ??

Many thanks ....

[Nagendra Kumar Nainar]

Hi Sandeep,

Since you are using BGP as PE-CE protocol, you need to see how ISP is advertising the default. Do they allow the update received from one site to other without tweaking any value?. If so, You could try advertising the default route from your central site with higher local preference. 

-Nagendra

[milan.kulik]

Hi,

IMHO, it has no sense to increase the local preference attribute on an eBGP connection.

The basic questions are:

Is the MPLS provider advertising your other site prefixes to your CE routers together with the default route? Or only the default route?

If also the site prefixes are advertised, you should also ask him if he would accept the default route advertised from your main site (HQ).

If yes, you can try to advertise it.

And finally the provider could stop advertising his default route and simply accept your default route advertised from your HQ.

But this would be a little dangerous if he wouldn't advertise the site prefixes from each site to the others - if your HQ connection would fail, all sites would lose thier connections to the others.

Definitely: I'd recommend to discuss with your provider!

Another question coming to my mind:

Do you really need a default route in your network?

Wouldn't it be safer to use a proxy in your HQ for other sites to reach the Internet?

Best regards,

Milan