Setting up a standby switch 2

[Moth]

Hi, No good at Cisco stuff at all, sorry if its a bit dumb!
2 x Catalyst 2900XLs. Want one to be a standby. Questions;
Do I put the standby in a group.
Do I put the command switch in a cluster group, then bind the standby to it?
How do you bind them together?
Thanks for any help.
Rgds, Steve

 

[fynx]

Hi Moth,
Can you clarify a couple of points...
How are you expecting the stanby switch to operate? As a 'hot standby' or cold?
How are you connecting the devices to both
switches? Multiple NICs /redundant transceivers..? or will you repatch the cables to the standby switch if the primary went toes up?

Post back and we'll send you sunshine...

Cheers
Phil. If everything is coming your way then you're in the wrong lane.

 

[Moth]

Hi Phil

Thanks for the reply. Basically, it needs to be a completely fault tolerant system. The standby will sit there and be wired up to the hubs. Presumably? have a wire to the main switch, and a wire to the rest of the network.

So when (if) it dies, the standby will kick in.

Hope that is ok, thanks, Steve

 

[fynx]

OK,

You have a bunch of hubs that you wish to interconnect using switches. This isn't completely fault tolerant as each hub is a single point of failure - but that aside, if you just want a fault tolerant 'core' then it's pretty simple to do.

If you have Gig ports on your switches then use them to fibre them together if not use Fast Ethernet Copper.

Configure these uplink ports as full duplex and set spanning tree on them to uplinkfast. Also configure the ports into a port group and set them to trunk. This will tolerate a cable failure between the switches and give you up to 2Gb/s FDX or 200Mb/s FDX between the switches.

Then just connect each switch to each hub (note: leave spanning tree as normal).

One of the switches will 'block' its ports to the hubs by using the spanning tree algorithm until such time as the other switch is not there.

If you need help with some of the commands (I think the way I have explained it sounds more difficult than it is) then post back and I'll show you the process.

Cheers & good luck
Phil. If everything is coming your way then you're in the wrong lane.

 

[Moth]

Hi Phil, OK, I think I get it, but yes some command info would be helpful. Could you also just explain where 'clusterng' comes into this? (if it does at all).

Thanks again, Steve

 

[wybnormal]

Keep in mind not to exceed 7 switches in depth for the default STP timers to work properly. The STP cutover is NOT instant.. it can take 5 to 50 seconds for the STP relect the root bridge, recalculate the converangce and general housekeeping. Even at 5 seconds, it's enough to knock certain protocols off and break the connection requiring a reboot. Other apps and protocols are more tolerant and it would be "transparent".

Also, do NOT configure portfast on ports connecting a switch to a switch, Portfast was designed for the connection to a PC. With portfast on a switch to switch, you can get a loop since you have short circuited the root bridge election process.

EVen if you dont have the gig uplink ports, you can always use 2 or 4 10/100 ports gathered into a Etherchannel. The 2 ports give a 400Mbps bandwith and 4 gives 800Mbps. STP is automaticly corrected by PAP ( Port Aggregation Protocol ) to keep if from becoming confused with all the ports connected.

THis is good article from Cisco about STP with nice configurations to look at and copy.

http://www.cisco.com/warp/public/473/5.html

Etherchannel is here:

http://www.cisco.com/warp/public/473/71.html

MikeS "Diplomacy; the art of saying 'nice doggie' till you can find a rock" Wynn Catlin

 

[Moth]

Phil

Any chance of posting back the commands you mentioned. It may just make it a bit easier.

Thanks for your help.
Steve

 

[fynx]

Hi Moth,
Bit of a haemorrhage with my last post was thinking one thing then typing the other way 'round.

Anyway - commands you'll need to perform the config...

1) Make the port channel for the inter switch link...
switch(config)#interface Port-channel1
switch(config)#no ip address
switch(config)#switchport trunk encapsulation isl
switch(config)#switchport mode trunk

2) Put a couple of ports in the port channel
switch(config-if)#switchport trunk encapsulation isl
switch(config-if)#switchport mode trunk
switch(config-if)#channel-group 1 mode on
(perform on each port you want in the channel)

3) configure ports that attach to ONLY PC'S as portfast
switch(config-if)#spanning-tree portfast

Good luck,
Phil.
If everything is coming your way then you're in the wrong lane.