Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 441)

Configuring vLAGs to minimize packet loss
This topic provides background on configuring a vLAG to minimize packet loss.
In scenarios where a vLAG spans more than one node, the vlag ignore-split command minimizes the
extent of packet loss in the event of one of the nodes in the vLAG going down, and also reduces vLAG
failover downtime. The scope of this configuration is per port-channel on LACP-based vLAGS.
In a case where connectivity between nodes is lost because of a fabric split (as opposed to one of
members going down), there will be duplication of multicast/broadcast packets. Brocade recommends
that you build redundancy in the fabric so that individual links are not single points of failure.
NOTE
With ignore-split active, a vLAG node reboot can result in a more than one-second loss while
interoperating with a Linux server/nic-team/CNA, because of premature egress of traffic from the server.
The figure below displays a dual-vLAG configuration with three legs of RB2, RB3, and RB4. If RB2,
RB3, or RB4 reboots while Host-1 is communicating to Host-2 or Host3, a momentary traffic disruption
may occur.
Configuring vLAGs to minimize packet loss
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