Preview Tool

Cisco Bug: CSCvw00075 - Unknown-Unicast ARP traffic being forwarded out of same ingress interface with PVLAN Configured

Last Modified

Oct 09, 2020

Products (1)

  • Cisco Catalyst 9400 Series Switches

Known Affected Releases


Description (partial)

On PVLAN deployments, ARP response traffic is getting sent out of the same ingress interface where it was received.
When performing a Fed Punt/inject Capture we are able to see the ARP packet in both directions. It seems that the injected packet gets sent back out the ingress interface after a vlan rewrite.

* Device is running 17.3.1
* Seen on Cat9400
* Both ARP Snooping and Private Vlan must be Configured.
* There has to be at least 2 interfaces with at least 1 of them configured with PVLAN.
* Issue can be triggered with both a PVLAN Trunk or a PVLAN Access port.
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.