Saturday, August 7, 2010

Unique VLAN ID for SEA failover control channel setup

Unique VLAN ID for SEA failover control channel setup

Always select unique VLAN ID – which dosn’t exist on any of your organization network to avoid conflict when setting up dual VIOS with a control channel for SEA failover.. failure to follow this may result in a network storm. ( Very important and I couldn’t find any note on IBM site about it)

Requirements for Configuring SEA Failover

One SEA on one VIOS acts as the primary (active) adapter and the second SEA on the second VIOS acts as a backup (standby) adapter.
Each SEA must have at least one virtual Ethernet adapter with the “Access external network” flag (previously known as “trunk” flag) checked. This enables the SEA to provide bridging functionality between the two VIO servers.
This adapter on both the SEAs has the same PVID, but will have a different priority value.
A SEA in ha_mode (Failover mode) might have more than one trunk adapters, in which case all should have the same priority value.
The priority value defines which of the two SEAs will be the primary and which will be the backup. The lower the priority value, the higher the priority, e.g. an adapter with priority 1 will have the highest priority.
An additional virtual Ethernet adapter , which belongs to a unique VLAN on the system, is used to create the control channel between the SEAs, and must be specified in each SEA when configured in ha_mode.
The purpose of this control channel is to communicate between the two SEA adapters to determine when a fail over should take place.


Gileb said...

Hello Santosh,
Having experimented the storm on my own network (i followed an old version of a redbook, now updated), i discovered a interesting parameter, to add on the switch, on which my vios are connected. Now, we always implement this setup, whenever a vio is connected. This is called the BPDU guard.
Hope that helps.

Santosh Gupta said...

Thanks for Value addition on my knowledge ...