Preview Tool

Cisco Bug: CSCup89543 - packet larger than 1496 fails when using local span

Last Modified

Sep 01, 2020

Products (1)

  • Cisco Catalyst 4000 Series Switches

Known Affected Releases

15.2(1)E 3.6(3)E 3.7(0)E

Description (partial)

with Default MTU 1500 set .
we configure LOCAL SPAN session :

monitor session 1 source interface Po4
monitor session 1 destination interface Te1/1/16 
monitor session 1 filter packet-type good rx  ---------- > this line is added automatically
here , no issue is seen .
all packets within MTU limits go through.

however , if you REMOVE "monitor session 1 filter packet-type good rx" manually ,
all packets larger than 1496 are dropped.

span is set on 4500X without 'filter packet-type good rx'
ping with packet size larger than 1496 fails
span source port is configuring as trunk mode.
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.