Guest

Preview Tool

Cisco Bug: CSCvu12905 - Cat6k - Sup2T - DHCPv6 control packets snooped by MLD when forwarded over VPLS circuit

Last Modified

Sep 01, 2020

Products (1)

  • Cisco Catalyst 6000 Series Switches

Known Affected Releases

15.5(1.0.14)SY5

Description (partial)

Symptom:
DHCPv6 control packets (whose IPv6 destination is the multicast address FF02::1:2) are snooped by MLD Snooping when forwarded over a VPLS circuit. These packets shouldn't be snooped as they are control packets and not regular multicast traffic.

Since the Sup2T is incorrectly snooping these packets, then they won't be forwarded over the VPLS circuit and will be silently dropped by the platform, unless the VPLS circuit is an mrouter port for the VLAN that is extended over the circuit.

Conditions:
- VPLS is configured on the Sup2T to extend the VLAN where DHCPv6 is being used.
- DHCPv6 messages need to traverse the VPLS circuit (i.e. if the DHCPv6 Server resides on the other end of the VPLS circuit).
- MLD Snooping is enabled on that same VLAN.
Bug details contain sensitive information and therefore require a Cisco.com 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.