redundancy in LAN

[Bab L]

Hi all.

Not sure if this is possible but can you create redundancy in the same LAN environment?

e.g. client has two core switch connected to each other via fibre in two separate rooms on same site. All switches are in same subnet. The servers are all connected to one of the switches.They want to setup up the same server enviornmet connected to the other core switch for redundancy. So when one switch goes down the servers will come up at the other end.

I cant see this working unless they are different subnet, but lets say we setup the server environment on the other end and turned off, will it work that way. So, we turn it on manually when the other switch goes down. The customer doesn't want to buy additional equipment for this setup.

Any suggestions will be great.

Thank you

[Leo Laohoo]

What is the model of core switches?

[Bab L]

The customer has currently got Juniper switches looking to replace them.

[Leo Laohoo]

Cisco switches support either Stacking or VSS.  

These will support sub-second failover of redundant links if configured correctly (like etherchannel). 

[Julio E. Moisa]

Hi

I think you are looking for FHRP solutions like HSRP, VRRP or GLBP, in order to have redundancy, but at least the servers should be connected to a switch (or couple) and these connected to the core switches. You also could investigate about NIC teaming. Now you should see if your core switches are able to support any FHRP.

The following links could be useful:

http://www.cisco.com/c/en/us/products/ios-nx-os-software/first-hop-redundancy-protocol-fhrp/index.html

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_52_se/configuration/guide/3560scg/swhsrp.html

http://networkerslog.blogspot.com/2011/04/network-redundancy-for-windows-servers.html

https://www.pluralsight.com/blog/it-ops/nic-teaming-windows-server-2012

:-)

[Bab L]

Thanks fort that info. I'll have a look.

The question is though, can there be redundancy with server having the same IP address connected in the same LAN environment?