Bug ID 422314: Multicast IPv4 or IPv6 packets can erroneously be looped back to the transmitting SFP interface on 2000, 2200, 4000, 4200 platforms.

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
11.2.1, 11.3.0, 11.4.0

Fixed In:
11.4.1, 11.2.1 HF15

Opened: May 30, 2013
Severity: 3-Major
Related AskF5 Article:
K14455

Symptoms

tcpdump will show an inbound echo of some outbound L2 multicast IP traffic on the 2.x interfaces.

Impact

This may cause an incorrect or confusing fdb entry to appear for the source MAC address if the multicast IP packet is being bridged through from one interface on the VLAN to another (IPv6 router advertisements for example). For sites using neither IPv6 nor MAC level multicast IPv4 this is unlikely to occur.

Conditions

This will only occur when transmitting IPv4 or IPv6 packets to Ethernet multicast or broadcast addresses, and only on the 2.x bank of interfaces of a BIG-IP 2000, 2200, 4000, or 4200 platform.

Workaround

The fix is simple, and can be implemented by editing an init script: In /etc/init.d/stratospfinit there is a line that reads: modprobe ixgbe max_vfs=$vfs,$vfs force_rss_sriov=1,1 lacp_target_queue=1,1 >/dev/null 2>&1 replacing it with a line that reads: modprobe ixgbe max_vfs=$vfs,$vfs force_rss_sriov=1,1 lacp_target_queue=1,1 L2LBen=0,0 >/dev/null 2>&1 will fix the problem (a reboot is required after the edit).

Fix Information

Correct erroneous loopback of L2 multicast IP traffic on 2.x interfaces of BIG-IP 2000, 2200, 4000, and 4200 platforms.

Behavior Change