Seeing no traffic in MSFC in core switch.

Unanswered Question
Sep 29th, 2009
User Badges:
  • Silver, 250 points or more


We have two core switches at clients site.Both the core switches are connected to WAN individually.So there are two WAN circuits. There is also a link between the 2 core switches.

One of the core switch-1 catalyst 6509 is showing no traffic in MSFC on vlan interfaces although it has spanning tree forwardoing ports from the access switches and it is also HSRP active switch.

What i am seeing that traffic though comes on link to this switch from the access switch but then it goes to the other Core switch -2 using the link between and it exits to WAN.

There hardly any traffic that exits from Core switch-1. I have checked routes , both the core switches have same routes from MPLS provider.

Any suggestions?

Thanks in advance.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 3 (1 ratings)
Giuseppe Larosa Tue, 09/29/2009 - 12:31
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

Hello Saju,

are the two boxes running the same IOS version?

on some older versions the effect of multi layer switching was to show very few traffic on SVI vlans far lower then real.

for return traffic box2 can be preferred for some reason.

But if HSRP active is on box1 it should be used by hosts on the client vlan.

Hope to help


singhsaju Wed, 09/30/2009 - 17:25
User Badges:
  • Silver, 250 points or more

Hi Guiseppe,

Thank you for your response.

yes the other core switch is 5000 series platform.

Do you know any bug id for it? To which IOS should i upgrade to? any suggestions.




This Discussion