Adding a switch to a VLAN'd network.

[maniac]

HOW?

 

It's a brocade switch on a Cisco network with two Cisco 45xx series switches at the Core. I know all the VLAN information, gateways etc. but how do you configure the new switch to work in the existing environment? I know how to program the switch via the console and have set the IP number and other information, but I don't understand how you get certain ports on certain VLANS and sucessfully uplink this to the rest of the network. I can add ports as tagged and untagged to VLANS within the switch, this is easy, but how do I tell it to uplink this to the rest of the system via a specific port, and how does it know where to send its traffic?

 

Any advice welcome as although I understand the principles behind VLAN's, I've never set them up and not really worked with them properly before. I'd like to save calling in an engineer to do this as I'm sure it can't be THAT hard really?

 

Mike.

[CyberNerd]

I can add ports as tagged and untagged to VLANS within the switch, this is easy, but how do I tell it to uplink this to the rest of the system via a specific port, and how does it know where to send its traffic?

.

 

 

Configure the uplink ports on both switches so they are in an aggregation group. Configure the aggregation group so that the ports are tagged with all the vlans you want to cross into your new switch.

[twin--turbo]

You need to set up a 802.1Q trunk between the two switched.

 

And make sure the vlans match ( much easier on Cisco to Cisco with VTP )

 

Rob

Edited July 12, 2012 by twin--turbo

[sonofsanta]

Aye, mark your uplink as trunk or hybrid and tag it with all the VLANs you will use on that switch, and leave it untagged as VLAN1. Then untag relevant ports as you would normally - e.g. the computer that connects into port 1/0/20 wants to be in VLAN 20, so mark that port as untagged with VLAN20.

 

If your switches use OSPF already (I forget how to check this on Cisco, my CCNA was a long time ago) and the Brocade can handle it as well, then they will deal with routing etc. themselves. If not, you may have to set static routes for all the VLANs on your network on the switch.

So if you have a VLAN that uses 192.168.100.0/24 as an address pool that is routed from a connected switch with IP 192.168.0.10, you would add a static route of

192.168.100.0 8 192.168.0.10

(again, unsure of how to set this on Cisco as I use Comware 5 these days, but the theory should be the same)

Rinse and repeat for every VLAN IP range with the relevant next hop switch, which may just be your core depending on your topology (and that next hop should already have a routing table set up). If you set up any new VLANs routed entirely from the Brocade, you'll need to add a new route to all your other switches too.

[twin--turbo]

You don;t want the brodace doing routing (if it supports it)

 

IVR ( inter vlan routing ) should be done by the 450x , which does support OSPF but is not needed in this case.

 

Rob

[twin--turbo]

Also,

 

you will need to confirm if the 450x's are runnin PVRST , and how that interacts with your Brocade (if it can) other wise you may introduce a new root bridge and stuff the network.

 

Rob

[CyberNerd]

You don;t want the brodace doing routing (if it supports it)

 

IVR ( inter vlan routing ) should be done by the 450x , which does support OSPF but is not needed in this case.

 

Rob

 

There is some merit in using near edge or edge switches as routers.

We have a couple of near edge switches doing OSPF it means that routing decisions can be made further away from the core. It takes load off the core and load off the uplinks. Furthermore any layer 2 issues will be contained to those specific zones rather than affecting the core switch and the rest of the network.

[twin--turbo]

True, but that's then a divergance form the current design of the network and would require new vlans, seperate ipsubnets, etc.

 

Rob