networking protocol_error ai_generated partial

IGMP: Report suppression detected on VLAN 100, multicast group 239.1.1.1

ID: networking/igmp-report-supression

Also available as: JSON · Markdown · 中文
78%Fix Rate
85%Confidence
1Evidence
2024-02-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
Cisco IOS 15.7(3)M active — — —
Juniper Junos 21.4R2 active — — —
Linux kernel 5.15.0-91-generic active — — —
Arista EOS 4.29.1F active — — —

Root Cause

Multiple hosts on the same VLAN are suppressing IGMP reports due to a misconfigured querier, causing the multicast router to lose group membership information and stop forwarding traffic.

generic

中文

由于查询器配置错误，同一VLAN上的多个主机抑制了IGMP报告，导致组播路由器丢失组成员信息并停止转发流量。

Official Documentation

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/software/release/17-9/configuration_guide/mcast/b_179_mcast_9300_cg/configuring_igmp_snooping.html

Workarounds

  1. 85% success Configure IGMP snooping querier on the VLAN to ensure consistent query generation: `ip igmp snooping querier 10.0.100.1` 
    Configure IGMP snooping querier on the VLAN to ensure consistent query generation: `ip igmp snooping querier 10.0.100.1`
  2. 90% success Enable IGMP explicit host tracking to bypass report suppression: `ip igmp snooping explicit-tracking` 
    Enable IGMP explicit host tracking to bypass report suppression: `ip igmp snooping explicit-tracking`
  3. 75% success Set the IGMP query interval to a lower value (e.g., 60 seconds) to reduce suppression window: `ip igmp query-interval 60` 
    Set the IGMP query interval to a lower value (e.g., 60 seconds) to reduce suppression window: `ip igmp query-interval 60`

中文步骤

  1. Configure IGMP snooping querier on the VLAN to ensure consistent query generation: `ip igmp snooping querier 10.0.100.1`
  2. Enable IGMP explicit host tracking to bypass report suppression: `ip igmp snooping explicit-tracking`
  3. Set the IGMP query interval to a lower value (e.g., 60 seconds) to reduce suppression window: `ip igmp query-interval 60`

Dead Ends

Common approaches that don't work:

  1. 70% fail

    This floods all multicast traffic to all ports, defeating the purpose of snooping and causing unnecessary bandwidth consumption.

  2. 60% fail

    Longer intervals actually increase the chance of suppression because hosts wait longer to respond, and the querier may time out before receiving reports.

  3. 80% fail

    Static entries do not account for dynamic group changes and require manual updates, leading to stale or missing entries.