Load balancing and redirection

[sweeann]

Hi,

I'm running an MPLS network and facing a problem balancing traffic and redirecting traffic when I have two HQ links. Eg. how can I direct branch A traffic to HQ link 1 and branch B traffic to HQ link 2 and redirect the traffic to the other link if one of the links go down? Do I use one or two VPN to achieve this or is there a command to do this?

Thanks,

sweeann

[nshahrin]

Hi there,

Do you have any IGP between branches and HQ.

If yes, how many routers u have at HQ. Assume u have 2, for CE branch A, default GW can set next hop to loopback HQ 1 and CE B, default GW can set to loopback HQ 2. However, if you have only one router at HQ, then use WAN IP as next hop.

And also, additional static route with higher AD for fail-over.

MPLS CORE ---HQ 1 (loopback0: 1.1.1.1/32)

HQ 2 (loopback0: 2.2.2.2/32)

inside CE A

ip route 0.0.0.0 0.0.0.0 1.1.1.1

ip route 0.0.0.0 0.0.0.0 2.2.2.2 240

but u need IGP ie ospf, eigrp for this to work.

rgds,

--shahrin

[ipotts]

Hello,

Are the dual HQ links PE to PE or CE to PE?

Thanks

Ian

[sweeann]

The HQ links are to the PE.

HQ CE ---------link 1-------------- PE

---------link 2--------------

So for instance we would like to have branch A & B traffic goes to link 1, while branch C & D traffic goes to link 2. And in the event link 1 fails, then traffic from branch A & B will flow to link 2.

Any cisco document covering the above? Thanks.

[ipotts]

The only way I can suggest is to use policy based routing, and set the next hop based on the source address on the PE. i.e. if the traffic is from branch 1, set the next hop to link 1 and if from branch 2 set it to link 2 and so on. If the PE is a 6500 with a Sup2 this is in hardware. If you don't have a box that does it in hardware, it can become very expensive in CPU cycles.

[mazhar71]

Hi Sweeann,

My answer is not you are exactly looking for. But to balance the load between 2 or more links you can configure "interface multilink XX". This type of configuration will balance your load using both links at the same time. But it doesn't send traffic of A to link 1 and traffic of B to link 2. It uses both link simultaneously and when one of the links fails , the other is used to flow the traffic. Routing traffic except destination address criteria is done using policy routing and policy routing is not available on the Cisco MPLS vrf implementation yet.

Regards