load-balance MPLS traffic on ether channel based on src-dst-ip on 3750

[N.ima0102]

Hi

In one of the development phases in our network, we have to load balance traffic flow on ether channel. But traffic flow is MPLS tagged.after some checking we have found out MPLS tagged traffic is not correctly load-balanced. Same configuration works correctly on normal traffic flow and load balanced.

Output of command "show etherchannel load" :

Non-ip : source XOR destination MAC

So I think 3750 load balances MPLS packet as non-ip packet and based on src-dst-Mac.

Is there any solution that switch can load balance based on layer 3 parameters, src ip and dst ip ?

Sent from Cisco Technical Support iPad App

[Giuseppe Larosa]

Hello Nima,

>> Is there any solution that switch can load balance based on layer 3 parameters, src ip and dst ip ?

No, this is not possible on a C3750.

Your only available options are source-MAC or destination-MAC but I'm afraid it will not provide better results

see

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_55_se/configuration/guide/swethchl.html#wp1275731

high end switches like C6500 should be able to handle MPLS traffic over a bundle.

but this is not possible on C3750

Hope to help

Giuseppe

[Reza Sharifi]

Hi Giuseppe,

From the link you provided, source/destination IP is available on the 3750s

With  source-and-destination IP address-based forwarding, packets are sent to  an EtherChannel and distributed across the EtherChannel ports, based on  both the source and destination IP addresses of the incoming packet.  This forwarding method, a combination of source-IP and destination-IP  address-based forwarding, can be used if it is not clear whether  source-IP or destination-IP address-based forwarding is better suited on  a particular switch. In this method, packets sent from the IP address A  to IP address B, from IP address A to IP address C, and from IP address  C to IP address B could all use different ports in the channel.

also:

Switch(config)#port-channel LOad-balance ?

  dst-ip       Dst IP Addr

  dst-mac      Dst Mac Addr

src-dst-ip   Src XOR Dst IP Addr

  src-dst-mac  Src XOR Dst Mac Addr

  src-ip       Src IP Addr

  src-mac      Src Mac Addr

Switch(config)#port-channel LOad-balance

Nima,

The 3750 series switches do not support MPLS.  They only support VRF Lite

HTH

Reza

Thanks,

Reza

[benl]

Nima,  did you ever figure out how to load-balance MPLS traffic over etherchannel?

We are trying to do the same thing.   We started with a 2960 switch which can load-balance based on IP src and dest addresses.  However, what I found was as soon as the MPLS tag was added, load-balancing was no longer being performed correctly using IP.  I believe what was happening was that the MPLS tag confused the switch and it fell back to hashing based on the MAC address. 

So we are back to square one trying to find a suitable switch with the help of our local rep.

I would be interested in knowing if anyone else has been able to do this successfully.

thanks,

Ben

[N.ima0102]

Hi

Unfortunately 2960 and 2750 and many other switches from cisco can not load balance MPLS packet tagged.

According to cisco documentats Only model from cisco that can load balances MPLS packet tagged is 6500 family with sepcial hardware.

sorry I could not find that document.but I am sure you can find it with some search on cisco web site.

Thanks