Switch Mirroring

[dwalsh]

Hello,

I have two 2950G switches. I'd like to have one as an online active connection and the other as a standby in case of primary failure. My assumption is that there's no automated failover capability (could be wrong on that), but is there some way that I can at least keep the configs sync'd so that I at least don't have to retype the same config both times. The actual failover can be manual (if necessary), but I'd like to create some way to have a non-technical person get things back up and running (i.e. by just switching a cable).

Thanks,

Dave

[Prashanth Krishnappa]

I am not sure what having an active connection to your spare would achieve for you. If the active swich were to fail, the ports on it will be dead anyway. So have the spare configured identical and ready to go and the person onsite can just move the cables to the spare switch if the active were to die.

[fabbasi]

Assuming that you already have 2 equivalent switches, my suggestion would be to keeps things as simple as possible.

Both switches can be configured similarly (i.e. VLANs, ports speeds etc) and connected to your LAN. Connect hosts into one switch, and in the event this fails, have the non-technical person move the host Ethernet cables one by one to the other switch. This way you get 100% redundancy and can perform periodic maintenance also. Remember that if you decide on a non-connected standby, then this device will have to be periodically tested by connecting to your LAN. There is nothing worse than having a standby which when needed goes 'pop' when you plug it in.

You can expand on this by using Gigastack connections and locating the devices on separate power supplies, but otherwise nothing too complex.

However, there are many other solutions that will enable someone to plug the replacement switch in and have a config automatically downloaded FTPd or TFTPd to it. This will require servers, DHCP and DNS configs and really only works if you already have a localised infrastructure that can handle this. For more info check out http://www.cisco.com/en/US/customer/products/hw/switches/ps628/products_configuration_guide_chapter09186a00801a6ba1.html#1086068

Good luck

[dwalsh]

Thanks for the recommendations. Yes, it probably does make sense to do as you suggest. However, what about cluster services? Could I make this environment in to a two switch environment; one being the command and one being the standby? Will this keep the configs sync'd.

I guess what I'm trying to get at here is something similar to the PIX failover capabilities (I know the cables still have to be moved, but along that line).

I never really used the CMS stuff of the 2950s before. I was told it was kind of kludgy.

Thanks,

Dave

[mjcole_mcp]

I have to ask, have you had a lot of issues with fault tolerance in switches? Once I saw one of three transformers blow on a 4006 (it only needs two, the transformer went after a power came back up after a long power outage.)

But I have never seen a need in any environment for redundant switching. Redundant ethernet cables would be nice (especially when someone drops floor tiles a little to hard), redundant WAN links are essential but in my limited experience ethernet switches never fail.

Michael

[s.debenito]

Hi,

You can achieve full "standby" functionality using the Cisco Network Assistant Software available at Software Center. It allows you to configure one switch as the "active" switch, and the other one as the "standby" switch. It also allows you to manage them using only 1 IP address.

Hope that helps.

Regards,

Sergio.