Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

Cisco Switch Clustering with VoIP

Has anyone used Cisco's Switch Clustering with their stacks of 3524PWR's? I am installing 26 3524PWR's in a new building and assigning IP addresses to each switch and later managing all 26 switches individually is a fair amount of work. I haven't used Cisco's cluster feature with voice traffic. I suspect it should work fine. I am reluctant to try it out in one of my voice installs. Any advice or experience would be greatly appreciated.

Thanks,

Tom.

8 REPLIES
New Member

Re: Cisco Switch Clustering with VoIP

Been a while since I played with stackable clusters, but it used to be that if your cluster controller fails the entire stack dies, leaving your users no data or voice! You might want to do a quick lab build with the latest firmware to see what happens.

How about trying one of the low end SNMP managers to make life easier. I can recommend SolarWinds or NetScanTools, but there are cheaper ones out there. There's also MRTG which I've not used but is highly spoken of.

New Member

Re: Cisco Switch Clustering with VoIP

We just noticed that Cisco had updated their cluster code and it now has "Hot Standby" code for layer 2. Which we thought was just too cool. You define a standby cluster controller and virtual IP address, just like HSRP. However, I agree it's not worth the risk of losing the whole stack.

We also use SolarWinds and life wouldn't be the same without it.

Thanks for your thoughts.

Tom.

New Member

Re: Cisco Switch Clustering with VoIP

Cool - I'd heard very vague rumours ages ago that they were thinking of doing something like this, glad they've done it.

Hope all goes well on your install.

New Member

Re: Cisco Switch Clustering with VoIP

Cisco did an excellent job with their layer 2 HSRP! I just finished setting up a lab with 3 Cat3524s configure in a cluster with the top switch as the commander and the bottom switch as the standby. I dual homed the stack to a Cat4006 with L3 module and hung my VoIP test lab equipment on the stack. Callmanager was on the top switch and I put a phone on each switch. I initiated a call between a phone on the top switch and a phone on the bottom switch and put the receiver of one phone to a radio. I put my laptop on the Cat4006 and started a continuous ping to the HSRP virtual address. With everything setup, pings going and phone call active, I started breaking individual links. I was amazed how well it everything worked. The ping would stop for a few seconds when I broke the forwarding link and then the standby switch took over. The phone call never disconnected. I lost sound for about the same amount of time with the pings when I broke the link for forwarding voice VLAN. (Note: I have uplinkfast on each Cat3524)

I think this feature has huge amount of value if you are stacking a lot of Cat3524's. You can still assign individual IP addresses to each switch, but clustering really reduces the management of the stack. All you need to remember is one IP address for the stack. Then from commander switch you enter the rcommand n to access other members of the cluster (i.e. rco 2 will take you to third switch in the stack. 0 is cluster commander).

I prefer to use CLI for managing Cisco devices. However the CMS browser software appears to work much better than the last time I used it. I upgraded the entire cluster from the browser interface and it worked pretty good. For some reason the Cluster commander failed to download the tar file from the TFTP server, but the other two switches completed successfully. I restarted the upgrade for the Cluster commander and this time it was successful.

Anyway Russ, I thought you would be interested in my test. The implementation of HSRP on the Catalyst 3500/2900’s looks and feels just like HSRP on Cisco routers.

After I finished beating on it some more in the lab and if all goes well, I am going to implement it into production. Yeehaw, nothing like stepping out and taking a little more risk.

New Member

Re: Cisco Switch Clustering with VoIP

Could anyone tell me where I can find Doc. for L2 HSRP? Thanks.

New Member

Re: Cisco Switch Clustering with VoIP

It is in the Catalyst 2900 XL and Catalyst 3500 XL Software Configuration Guide in the section "Clustering Switches" Here's the url:

http://www.cisco.com/univercd/cc/td/doc/product/lan/c2900xl/29_35wc/sc/swgclust.htm

Good luck,

Tom.

New Member

Re: Cisco Switch Clustering with VoIP

Tom we have used Clustering and are in the process of changing because from what we have been told VLAN's will not filter down to the stack.

New Member

Re: Cisco Switch Clustering with VoIP

Well, unfortunately someone gave you some incorrect information. I have four VLANs defined on the Cat4006 and three clustered Cat3524’s connected to the Cat4006 via DOT1Q trunks. The Cat4006 is the VTP server and the clustered Cat3524 are VTP clients. Then each port on the Cat3524 is a DOT1Q trunk with a Voice VLAN and a native VLAN for data. All the VLANs are trunked properly by the DOT1Q encapsulation. I am not sure why someone was thinking that clustering would disable the ability to trunk between the clustered switches. I suspect that they may not have properly set up the trunks. Common errors are mismatched native VLAN on each end of the trunk or VLANs removed from the trunk.

354
Views
0
Helpful
8
Replies
CreatePlease to create content