In switch LAG , 1 port taking more traffic than others.

  • 0
  • 1
  • Problem
  • Updated 1 year ago
  • Solved

We have extreme inter switch with 7 ports in LAG all in different slots.
And we can see 1 of the 7 ports is taking high utilization apart from other 6

 

As these on different slots, so any input on the issue.
If anything can be checked, (no errors/no congestion) but in peak time sometimes we get ping drop.

 

show port 1:4 1:5 2:13-15 2:19-20

 

Port     Link    Link   Rx             Peak Rx       Tx            Peak Tx

         State   Speed  % bandwidth    % bandwidth   % bandwidth   % bandwidth

================================================================================

JBCIMS-U> A       1000     16.35         36.00         29.97           69.66

JBCIMS-b> A       1000     15.42         36.51         14.90           35.03

EVO_Cont> A       1000     31.43         74.81         14.30           32.22

RNCVKIRJ> A       1000     15.50         36.19         14.54           32.33

To_JAISW> A       1000     15.53         40.01         14.61           35.58

RJGMSC5_> A       1000     15.93         40.32         14.81           34.99

RJGMSC4_> A       1000     16.37         40.78         14.88           36.04
Photo of Saurabh Makkar

Saurabh Makkar

  • 262 Points 250 badge 2x thumb

Posted 1 year ago

  • 0
  • 1
Photo of Kawawa

Kawawa, GTAC

  • 3,272 Points 3k badge 2x thumb
It really depends on the characteristics of your traffic and the hashing that is being used when determining what link to forward a stream across.  Are you able to confirm what algorithm you're currently using and whether the traffic traversing the LAG is from a specific device. LAGs are primarily designed to aggregate multiple links as opposed to provide load balancing.  Therefore if you have (say) the same two devices talking across the LAG, with an L2 and L3 algorithm, these streams will most likely be forwarded over the same LAG port.
(Edited)
Photo of Brandon Clay

Brandon Clay, Escalation Support Engineer

  • 13,304 Points 10k badge 2x thumb
Hi Saurabh,

In addition to what Kawawa posted, you may want to take a look at the following GTAC Knowledge article:
https://gtacknowledge.extremenetworks.com/articles/Q_A/Why-is-traffic-distribution-across-ports-in-a...