3com/HP 5500 G Stacking

[siparfitt]

HI totally new to this hope you can help..
I have a network setup with a 5500G 24 port as my main core switch. this then trunks to various other 3com switches 4800 ect.. with 3 Vlans for data, telephones and management.

I would like to be able to add another 5500G as a back up / redundancy switch in another location on the site.. Hopefully this could be a automatic changeover incase main switch fails.. i have plenty of spare fibre links between all switches. i See i could use LACP but my main switch is the default gate way of my network?? little lost bit out of my depth on this one..

How would i do this?

Regards Si

 

[VinceWhirlwind]

OK, so your "core" switch is the default GW for everything. What you need is a second "backup core" switch which takes over the default GW address if the "core" switch goes down.

You can implement this using VRRP.

Briefly, your core switch, being the default GW, has IP addresses as follows:
VLAN 10 DATA 10.1.10.1/24
VLAN 20 VOICE 10.1.20.1/24
- You change these "physical" addresses to
VLAN 10 DATA 10.1.10.2/24
VLAN 20 VOICE 10.1.20.2/24
enable VRRP and set the "virtual" address to the 10.1.nn.1/24 address. The "core" then responds to packets addressed to the .1 addresses as if it was actually addressed with that address.

Then, add your "backup core" with
VLAN 10 DATA 10.1.10.3/24
VLAN 20 VOICE 10.1.20.3/24
enable VRRP and set the "virtual" address to the 10.1.nn.1/24 address. The "backup core" does not respond to packets addressed to the .1 addresses, UNLESS, it loses communication with the "core". If it detects the "core" is gone, the "backup" will start responding as if it was actually addressed with the .1 addresses.

Ensure your inter-connection between the two switches consists of multiple fibres using LACP adding up to sufficient bandwidth and preferably using more than one path so that a single event can't knock all the links down in one go.

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02581983/c02581983.pdf

page 223-226.

Configurations on Switch A
interface Vlan-interface1
ip address 202.38.160.1 255.255.255.0
vrrp vrid 1 virtual-ip 202.38.160.111
vrrp vrid 1 priority 110

Configurations on Switch B
interface Vlan-interface1
ip address 202.38.160.2 255.255.255.0
vrrp vrid 1 virtual-ip 202.38.160.111