Currently CSM1 is active and CSM2 is standby.
All the traffic currently flowing though the CSM1 which is currently Active which is perfectly correct. Now we Need to check the redundancy behaviour by bringing down the CSM1
and make CSM2 as active so that all the traffic should flow though it.
Can someone let me know how to bring the Active CSM1 to standby so that CSM2 to become Active and CSM1 to go standby??
Do I need to do something on CSM1? or on the Cat6500.
NOTE: 2 CSM are in 2 different Cat 6500 Chasis.
Thanks in advance.
on Cat6500 with Active CSM you can power off the ACtive CSM which will cause Standby CSM to become active
"no power enable module X"
where X is the slot in which CSM is installed.
If you just want to switch roles and do not want to reload/restart the CSM then
"clear module csm
for more details
Hope this helps
Syed Iftekhar Ahmed
I dont want to power off the module. And how can I use the clear module command as I have enabled the prempt on my csm and the pdf documents says dont use it if you are configured prempt command.
Any comments from you on this???
You will have to disable preemption before using this command.
If you do not then due to high priority value the Currently active CSM will preempt the active status back from the standby after a switchover.
Syed Iftekhar Ahmed
What happens if I increase the priority on CSM 2 will it take over the role of Active? If yes will there be any impact ? Will all the active sessions from CSM1 will be pour down to CSM2????
Thanks in advance,.
Connection redundancy prevents open connections from ceasing to respond when the active CSM fails and the standby CSM becomes active. With connection redundancy, the active CSM replicates forwarding information to the standby CSM for each connection that is to remain open when the active CSM fails over to the standby CSM.
Have you configured connection redundancy like as follows,:
Router# configure terminal
Enters router configuration mode.
Router(config)# no ip igmp
Removes IGMP snooping from the configuration.
Identifies a virtual server and enters the virtual server submode.
virtual ip-address [ip-mask]
protocol port-number [service
Configures the virtual server attributes.
Associates a server farm with a virtual server.
sticky duration [group
Ensures that connections from the same client use the same real server.
replicate csrp sticky
Enables sticky replication.
replicate csrp connection
Enables connection replication.
Enables the virtual server for load balancing.
group group-id vlan vlanid
Configures fault tolerance and enters the fault-tolerance submode.
Sets the priority of the CSM.
Sets the time for a standby CSM to wait before becoming an active CSM.
Allows a higher priority CSM to take control of a fault-tolerant group when it comes online.
This example shows how to set fault tolerance for connection redundancy:
Router(config-module-csm)# vserver VS_LINUX-TELNET
Router(config-slb-vserver)# virtual 10.6.0.100 tcp telnet
Router(config-slb-vserver)# serverfarm SF_NONAT
Router(config-slb-vserver)# sticky 100 group 35
Router(config-slb-vserver)# replicate csrp sticky
Router(config-slb-vserver)# replicate csrp connection
Router(config-module-csm)# ft group 90 vlan 111
Router(config-slb-ft)# priority 10
Router(config-slb-ft)# failover 3
If you have done your configuration like this then this is a configration for connection redundancy.
Kindly check if your configuration is similar to the above .
Kindly consult the following URL in this regard:
You are right.
If premption is on and you increase the priority then the csm with highest priority will take over the active role.
Connections are replicated provided connection replication is configured
Your configs need to have "replicate csrp connections" under vserver configuration for connection repliaction
and "replication csrp sticky" for sticky table replication.
If configured, Active CSM copies its connection table and sticky table over to the backup CSM.
In the case of failover, the backup CSM knows what connections were going to which servers.
However there is a possibility if Active CSM is in middle of transmitting connection info and failover happens then few
connections will be lost. Stanby CSM needs complete connection information and cannot serve existing connections if
it has partial information about any connection.
Syed Iftekhar Ahmed