Multilink interface shows counters and not physical interface

[santhosh.mc]

I can not see any packets on the physical interface but the multilink interface shows packets, i would like to know the cause for the same

sho inter Serial5/0/0/5:0 | in s/s
  30 second input rate 0 bits/sec, 0 packets/sec
  30 second output rate 0 bits/sec, 0 packets/sec

sho inter Serial5/0/0/6:0 | in s/s
  30 second input rate 0 bits/sec, 0 packets/sec
  30 second output rate 0 bits/sec, 0 packets/sec

sho inter Serial5/0/0/7:0 | in s/s
  30 second input rate 0 bits/sec, 0 packets/sec
  30 second output rate 0 bits/sec, 0 packets/sec

sho inter mu 2 | in s/s
  30 second input rate 2612000 bits/sec, 1346 packets/sec
  30 second output rate 4076000 bits/sec, 1384 packets/sec

sh pp multilink

  Member links: 3 active, 0 inactive (max not set, min not set)
    Serial5/0/0/5:0
    Serial5/0/0/6:0
    Serial5/0/0/7:0

[mavespig]

Hi Santosh,

when you bundle a serial interface on a multilink, all the logic of the interface is moved to the multilink.

Therefore you will not see the counters incrementing in show interface serial x/x, you need to check the multilink interface.

When 2 or more links are bundled, show interface multilink reports the aggregate info of all the links.

Note that if you start having errors/drops on a multilink interface (and there is no QoS configured), you cannot know if they are caused by a specific serial interface. In that case you should remove one serial link from the bundle, test it (e.g. extensive ping test, physical loopback), and if it's clean you add it again to the bundle and do the same for the second link, and so on.

Hope this helps

Marco