Operating instructions

194 Cisco Systems Intelligent Gigabit Ethernet Switch Module
Figure 7-22 What Trunk Failover can protect against
Introduction to Trunk Failover configuration
Two types of link state commands are required on the IGESM to support Trunk Failover
1. Global command (enables the link state group, up to 2 groups supported):
link state track X
(X = 1 or 2)
2. Interface command (assigns ports to group):
link state group X {upstream | downstream}
The following are the rules for placing the upstream and downstream commands:
–The
upstream command can only be placed on external uplinks (g0/17 –g0/20) or
logical interfaces (Etherchannel) on the external uplinks.
– Normally place
upstream command on Etherchannel ports (int poX).
– Only place the
upstream command on physical ports (G0/17 - 20) if Etherchannel
uplinks are not being used.
–
Downstream command can only be placed on g0/1 – g0/14
–Placement of
downstream command will depend on specific environment, but
assuming all blade servers using NIC Teaming, then all internal ports (G0/1 – 14) will
receive a “downstream” command
A third type of command is available to check the status of the Trunk Failover configuration:
show link state group detail
Shows what ports are assigned to upstream ann downstream and the status of any
configured Trunk Failover groups.
17 18 19 20
CIGESM Top
6500 -1
1 2 3 4
6500-3
1 2 3 4
17 18 19 20
CIGESM Bot
Po1
Po2 Po2
NIC 1 NIC 2
BladeServer 1
Po1Po1
BladeCenter
Topology 1 - Trunk Failover
Teamed
Active/Standby
Logical NIC Interface
VLAN X
If IGESM fails in such a way that the
link toward the BladeServer goes
down, or NIC fails, BladeServer can
sense this and redirect traffic out the
other NIC toward the bottom IGESM –
NIC Teaming can take care of this
without the need for trunk failover
If failure anywhere on the link
toward the upstream switch, NIC on
BladeServer does not know about
the failure and may continue to
send traffic toward the top IGESM,
which will discard the traffic - Trunk
Failover feature addresses this
issue
X
X
X
X
X