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Cisco Bug: CSCvu13343 - ERSPAN n7k /w "filtering" results in session stuck in "No operational src/dst" until flapping dst ip

Last Modified

May 26, 2020

Products (1)

  • Cisco Nexus 7000 Series Switches

Known Affected Releases

7.3(5)D1(1) 8.2(5)

Description (partial)

Symptom:
When enabling a secondary ERSPAN session using IPv4 filtering on a Nexus 7000 with F2E linecards, the ERSPAN session will be held "down" with the Reason: "No operational src/dst". Even after a flap "shut/no-shut" of the session this will remain. Removing and re-adding the session will result n the same behavior.

Conditions:
This issue occurs when first adding a secondary ERSPAN session that utilises filtering of IPv4 on Nexus 7000 using the F2E linecard. This has yet to be tested on other linecards so it could possibly be a issue on other cards.This issue does not appear to occur when there is no "Filter" configuration.

<pre>
# Adding the following configuration into the switch
monitor session 28 type erspan-source
description TAC_TESTING_ERSPAN_7k
erspan-id 2
vrf erspan
destination ip 192.0.2.111
source interface port-channel903 both
filter frame-type ipv4
filter frame-type ipv4 src-ip 10.0.0.0/24
filter frame-type ipv4 dest-ip 192.168.0.1/32
no shut

# Will result in the following
n7k1(config-erspan-src)# show monitor 
Ssn#  State Reason                 Description                      Type
----- ----- ---------------------- -------------------------------- ----------
24    up    The session is up      TAC_TESTING_ERSPAN_7k            erspan-src 
28    down  No operational src/dst TAC_TESTING_ERSPAN_7k            erspan-src					<<<<<<<<<< Stuck "down"
</pre>
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