networking protocol_error ai_generated partial

IGMP: report suppression on port Gi0/1, ignoring membership report for 239.0.0.1

ID: networking/igmp-report-suppression

Also available as: JSON · Markdown · 中文
78%Fix Rate
83%Confidence
1Evidence
2023-06-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
Cisco IOS XE 16.9.5 active — — —
Cisco IOS XE 17.3.3 active — — —
Juniper Junos 21.4R1 active — — —

Root Cause

An IGMP snooping switch suppresses duplicate membership reports from the same source within a query interval, causing multicast traffic loss if the only reporter is suppressed without a backup querier.

generic

中文

IGMP监听交换机在同一查询间隔内抑制来自同一源的重复组成员报告，如果唯一报告者被抑制且无备份查询器，则导致多播流量丢失。

Official Documentation

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/software/release/16-9/configuration_guide/mcast/b_169_mcast_9300_cg/m_igmp_snooping.html

Workarounds

  1. 75% success Configure IGMP querier on a different router or enable IGMP proxy reporting to ensure at least one report is forwarded: `ip igmp snooping querier` and `ip igmp snooping proxy-reporting`. 
    Configure IGMP querier on a different router or enable IGMP proxy reporting to ensure at least one report is forwarded: `ip igmp snooping querier` and `ip igmp snooping proxy-reporting`.
  2. 80% success Set the IGMP robustness variable to 2 or higher on the querier to allow for lost reports: `ip igmp robustness-variable 2`. 
    Set the IGMP robustness variable to 2 or higher on the querier to allow for lost reports: `ip igmp robustness-variable 2`.
  3. 95% success Use static IGMP group membership on the switch port for critical multicast streams: `ip igmp snooping static-group 239.0.0.1 vlan 100 interface Gi0/1`. 
    Use static IGMP group membership on the switch port for critical multicast streams: `ip igmp snooping static-group 239.0.0.1 vlan 100 interface Gi0/1`.

中文步骤

  1. Configure IGMP querier on a different router or enable IGMP proxy reporting to ensure at least one report is forwarded: `ip igmp snooping querier` and `ip igmp snooping proxy-reporting`.
  2. Set the IGMP robustness variable to 2 or higher on the querier to allow for lost reports: `ip igmp robustness-variable 2`.
  3. Use static IGMP group membership on the switch port for critical multicast streams: `ip igmp snooping static-group 239.0.0.1 vlan 100 interface Gi0/1`.

Dead Ends

Common approaches that don't work:

  1. 85% fail

    Disabling snooping floods all multicast traffic to all ports, wasting bandwidth and potentially overwhelming receivers.

  2. 70% fail

    Longer intervals delay group join/leave detection, causing prolonged traffic blackouts after topology changes.

  3. 90% fail

    The switch still suppresses if the report matches an existing group state; manual injection does not reset the suppression timer.