Two 3750's Redundancy - Do I need to Stack?

[JonB93]

I'm looking to create some redundancy with our server switches (3750x).   We only had one initially but the PSU failed, which took down our servers, so we ordered another one and I'm looking to have some redundancy in case it happens again.

Do I need to stack them? I've never done this before.  I know it treats both as one logical switch, but I wanna make sure I connect everything right.  This is a drawing I made up of how I think it will be done. Although I think my server has 4 nics, so maybe I would just do 2 to one switch and 2 to the other right?  Any other advice or things I'm doing wrong?

[Flavio Miranda]

Hi

 You are right.  The only advise I have is for port-channel use interface from both switches. This way if the first one fail, the second one keep connected.

https://community.cisco.com/t5/networking-knowledge-base/how-to-configure-cross-stack-etherchannel-on-cisco-catalyst-3750/ta-p/3128099

[balaji.bandi]

yes stacking will give high availability

high level - make sure switch models are same and compatable, version of code should be same, when you stack, you need to relaod to take effect stack config.

stacking option you can read below document :

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-3750-series-switches/71925-cat3750-create-switch-stks.html

Core connection - make sure you split the connect in to two switches, if switch 1 fails, switch 2 can still serve the purpose.

Server connection - also same split to Switch 1 and Switch 2, make Port-channel for high redundancy.

Good to even Connection to load balance equivally suggested.

[JonB93]

Hi, what do you mean by your "core connection" comment. Do you mean I should also have an etherchannel coming from core to the 2nd switch (as denoted in my blue connection) ?

[balaji.bandi]

here is my suggestion :

[MHM Cisco World]

there are two connection here 
Server <<- here you need stack if you run any teaming 
Core Switch <<- from point one if you decide to stack SW then from Core to both SW you can use PO cross or PO to one of SW. 
what is different 
if you config PO to each SW then one of PO will be STP BLK 
if you config PO as PO cross then both PO link will STP FWD

[JonB93]

Thank you all, I think it makes sense. Last question, as I've never done stacking.  Is it just connecting the cables in a cross fashion physically and then defining a primary member in the software and away I go?  I was glancing over this:Create and Manage Catalyst 3750 Switch Stacks - Cisco

and it seems pretty basic.  Do I console in any one of the switches and do my config and it will be like its the same on the other switch?  I'm just confused there. Ty

[MHM Cisco World]

all SW will appear as one SW so the config done in master and apply to all other SW.

[JonB93]

All,

I booted up the stack and there is a version mismatch.  By the looks of it, the newest 3750x we bought has 15.2 on it, and the old one has 12.2.  We don't have a smartnet contract.  How do I upgrade the old device, as I'm guessing that is the issue?

[Flavio Miranda]

Hello

 that´s right. Same version is one of the requirements for stack.   Copy the IOS from one switch and pull off to your machine and  install into the other switch.

 Setup a TFTP server on your PC, stablish communication with the switch and run

copy flash: <ios> tftp <your PC IP address>

[JonB93]

Could I also just do  copy flash0: flash2:   ?     or maybe its  copy flash0:nameof.bin flash2:nameof.bin

[Flavio Miranda]

you can do this

 From one switch:

tftp-server flash:image_name

then, in the other switch

copy flash:<ios>  tftp:<ip of the other switch>

[JonB93]

Well the problem is, they arnt on the network yet. They are sitting on my desk and I'm consoled into them. lol So tftp doesnt really work. They are stacked too which is why I thought I could just transfer between them.

[Flavio Miranda]

Remove the stack. Setup like this

sw1:

int vlan 1

ip add 192.168.1.1 255.255.255.0

Sw2:

int vlan 1

 ip add 192.168.1.2 255.255.255.0

Then, plug one cable in one port and connect in the other. Just make sure the ports are on  vlan 1

[MHM Cisco World]

same 3750x platform HA ?