Multihomed BGP - 100% Link Load

[schimeha1977]

Hi !

I am running into troubles in a multihomed BGP setup.

(GRX Backbone - private network for mobile operators exchanging their GPRS roaming traffic)

one link (Link1) is completely saturated (RX Load)- whereas the load of the other link (Link2) is nearly zero.

So I tried to use "AS PATH PREPEND" on Link1 by adding my AS once which resulted in saturating link2 - the load of Link1 reduces to nearly zero.

What I tried to achieve was some sort of load-balancing - but not a switch to the other redundant link.

I would be very grateful to get some support from you.

Cheers

Hans

[Georg Pauwen]

Hello Hans,

are you multihoming from a single router ? If so, you cannot really do load balancing, just load sharing, since BGP will only select one best path. You will either need to separate the IP address space or the BGP AS numbers in order to achieve the load sharing.

You can post your configuration, and I can try and add the appropriate commands.

You also might want to check the following document:

Load Sharing with BGP in Single and Multihomed Environments: Sample Configurations

http://www.cisco.com/en/US/partner/tech/tk365/technologies_configuration_example09186a00800945bf.shtml#conf4

Regards,

GP

[jrahm]

If you have only one subnet to advertise, there's not much you can do unless your ISP is willing to accept a split subnet for use only within its own network (Savvis used to do this)