No proper Etherchannel load balancing

Unanswered Question
Nov 10th, 2008
User Badges:

We have etherchannel between cat6000 and cat2970. 2970 connected to many users using modems through ubr router. Etherchannel circuit is not load balancing the sent traffic towards 2970. I tried srce-dst-mac,src-dst-ip dst-ip. circuit utilization is high on single port.


I believe etherchannel load balancing is independent for each device.


i thought destination based forwarding would work but it is not.


There is no errors what so ever on interfaces


Can some one help me out.


Thnx

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
Giuseppe Larosa Tue, 11/11/2008 - 00:25
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Chandu,

if I understand correctly your scenario is:


c6000 --- channel --- c2970 -- UBR NAS router --- users via modems


if at the other end there is only one user that is the UBR router load-balancing on MAC addresses provides no results.

Unfortunately the ubr router could be using L2TPv2 to concentrate user PPP sessions or other form of tunneling: if so even trying to load balance using IP addresses can be useless.

If you can access the UBR router is important to understand what type of traffic is sending out /receiving because it is possible that is all inside L2TP packets.


Hope to help

Giuseppe


chandu.84 Tue, 11/11/2008 - 07:52
User Badges:

Thnk you so much for your reply.


We have 802.1q tunnelin on c6000 and no type of tunnelin on cmts(ubr). I do not know how to get to know what type of traffic is passing through,..... can u kindly help me out with a suggestion.


Thnx a ton

Giuseppe Larosa Tue, 11/11/2008 - 11:19
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Chandu,

I was thinking of possible reasons for a single IP flow.


The remote users accessing via modems are terminated on the UBR router ?


on the link of the UBR use


int fa0/0

ip accounting output-packets


these tell you the IP flows outgoing : inverting IP source and IP destination you should have an idea of the variety of traffic.


Use

sh ip accounting


after some minutes


Another thought :

is the etherchannel a dot1q tunnel on the c6000 side ?

this could have an impact on what you see


Hope to help

Giuseppe


dbellamkonda Tue, 11/11/2008 - 11:27
User Badges:

Thnx yup,, etherchannel is dot1q trunk and 8021q tunnel. what impacts do we have

Actions

This Discussion