Redundant Core Switches

[Ozz_1]

Hi. I'm designing a network, and planning to use a 2948 for the core, with 3 2626PWR for access. I'm gonna have separate VLANS per department, with the 2948 doing the inter-VLAN routing. My question is this: to make my core redundant, could I add a second 2948 in a spanning tree configuration? The reason I ask is because spanning tree is a Layer 2 protocol, while inter-VLAN routing takes place at layer 3, so I'm wondering if in a failover scenario, the second 2948 would handle inter-VLAN ruting as well. I guess what I'm looking for is a form of device redundancy, something like HSRP, VRRP or BSD's CARP, which I'll use for my firewalls.

Thanks.

[Matt Hobbs]

For VRRP you can use the 5400/3500/6200 with the Premium Edge License.

XRRP is a similar thing, which is included on the 5300/3400's.

I'd look at the 5400/3500's for your particular needs.

[Ozz_1]

Thanks for your reply. I just saw that the price for the premium license is $2,400, on top of the $5,700 for the switch Do you think it would be better (cheaper) to just buy a switch with this capability built in?

[Mohieddin Kharnoub]

Hi

Thats true.

For a full redundant network you need both L2 Redundancy that can be achieved be a nice plan of MSTP.

And also you need L3 redudancy which i believe Matt already spoke about it.

One more thing i would like to add, XRRP is an HP proprietary protocol while VRRP is an IEEE standard one.

Each one has its own advantages and disadvantages, and from my experience, XRRP is faster recovery than the VRRP.

But in a complicated environment i would go for the VRRP for more scalability in the Network.

Good Luck !!!

[Ozz_1]

Thanks for your replies!

I see that the price of the premium license is $1,549. Added to the $5,700 cost of the switch, do you think it would be better to buy a switch with the capability built in?

Additionally, to make my access layer redundant, I'm planning to put two switches in each office, (probababy the 2626PWR, we're putting in an IP PBX this year), connecting half of the users to each, with a 2Gbps LACP uplink to the core. I assume that I'll only have to put the 2 switches in the same VLAN?

[Ozz_1]

Oops, didn't remember that I'd already posted the bit about the cost...lack o' sleep due to completing the budget...

[Paulen]

I really would try to avoid L2 redundancy mechanisms. They tend to "have issues", and get unstable - at least in a bigger scenario. Use plain routing with loop detection.