3750 Stack - Resiliency

[pnschurr]

Hi All,

Two 3750's in a stack. One is Master, other is Slave.

Having read the white-paper at http://www.cisco.com/en/US/products/hw/switches/ps5023/products_white_paper09186a00801b096a.shtml

If the Master crashes or loses power, the Slave will become the Master and continue running.

Question... will it use the current config the original Master was running? (meaning, is the current config maintained on ALL stack members).

And, does the Slave need to reboot to become the Master? What sort of cut-over time is required before service via the remaining switch is restored.

Sorry, but I don't have a spare pair to play with.

peter

[jackyoung]

The configuration should copy from master to slave automatically. If the power lost, the slave will become master and no need reboot. However, I don't have the cut-over time on hand, what I tested before is no downtime in the slave unit that due to it is still running as a switch. The slave is just like an extendion of the master switch w/ simple management domain. Moreover, the master power lost, so all the connections at master will be lost too.

Hope this helps.

[pnschurr]

Yeah, thanks for that.

The issue is that I'll be routing out the stack.. one L3 interface on each switch in the stack. The point is that if one stack fails, downstream switches can still route out the other physical path - as long as the other switch continues as Master (and therefore L3 forwarder).

peter

[jackyoung]

IC, I am sorry that I did not try it at L3 routing / switching. As I know, once you stack the switches, it acted as single unit. When the master power lost, one of the interface to remote router down, then the routing protocol will take effect and select another path for outgoing. The remote side will also update the routing table to select the slave as next-hop (if master is preferred path originally).

Hope this helps.