SFM Redundancy
Switch Fabric Module (SFM)
page 4-4
OmniSwitch 8800 Hardware Users Guide
December 2004
SFM Redundancy
The OmniSwitch 8800 allows for redundancy in the Switch Fabric Modules. In order for the switch to
operate, there must be four working SFMs in place. A fifth SFM can be added in case one of the four fails.
If an SFM fails, and a redundant SFM is in place, then the redundant SFM takes over for the failed SFM,
with no loss of switch running time. A warning message is sent to notify the switch administrator that a
failure has occurred and that the redundant SFM has taken over.
SFM Failover Sequence
The figure below illustrates the SFM failover sequence:
Redundant SFM Failover
1
The OmniSwitch 8800 is running with the SFMs in slots 1 through 4 controlling traffic. The SFM in
slot 5 is a redundant module.
2
The SFM in slot 2 fails.
3
The redundant SFM in slot 5 takes over for the SFM in slot 2. The switch is now functional again with
the SFMs in slots 1, 3, 4, and 5 handling traffic.
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
1
5
4
3
2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
1
5
4
3
2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
OS8800-SFM
OK1
OK2
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
AC OK
DC OK
TEMP
FAIL
1
5
4
3
2
!
SFM 2 fails or
is taken offline
!
SFM 5 takes
over for SFM 2
1: Redundant SFM
Configuration
(Redundant SFM
is slot 5)
2: SFM 2 fails
3: SFM 5 takes over
for SFM 2
