Procurve to Cisco VLAN Trunking

[Ehren8879]

I refer to trunking in Cisco terms or HP's tagging.

I'm just starting to get a little bit deeper into our switched network, so please bear with my ignorance. I've got a Procurve switch in one building and a Cisco IOS Switch in another. Both switches are one network configured on the native vlan 1, talking to each other over a fiber access port. I'd like to create a second vlan for another network on the HP switch and extend it to the Cisco. I'd like to run this config process by you guys in case something about this won't work.

Procurve: What I'm trying to do here is establish a tagged port and put vlan 1 and 122 on it. Also create vlan 122 and assign some ports to it.

vlan 1
tagged 45 (current access port, make it the trunk port)

vlan 122
name new_vlan (example)
untagged a,b,c (need three ports for new network)
tagged 45 (trunk between switches)


Cisco: Basically I'm trying to do the same thing here, but vlan 122 will require a couple more ports.

#create vlan
interface gig 0/a - d (vlan 122 network ports)
switchport
switchport mode access
switchport access vlan 122
no shutdown
*** Do for all ports part of vlan 122

#trunk
Switch(config)#interface gig 0/x (the fiber trunk port)
Switch(config-int)#switchport trunk encapsulation dot1q
Switch(config-int)#switchport trunk allowed vlan 1, 122
Switch(config-int)#switchport mode trunk

At this point I'm hoping to have achieved traffic flowing on the default vlan 1 again as well as vlan 122 between the two switches. I have read and been advised that I should ultimately move my traffic off vlan 1, using it solely for management purposes. I fully plan on doing that however I'll be making this change in the early hours on a production network, so my config time is limited. Any and all advice and constructive criticism is appreciated.

 

[corge]

On the HP side, if you want VLAN data to go to a Cisco trunked port....then just tag the VLANs, don't untag them on that port.

For instance, you have VLANs 80, 81, 82 and 83. On HP, tag those VLANs. On Cisco, you can either allow all by issuing the "switchport mode trunk" command or allow only certain ones by doing the "switchport trunk allowed ....." command.

Untagging a VLAN on the HP with set that vlan as the native vlan for that port, and then you can tag more if you wish it to send/receive more vlan traffic on that port.

 

[Ehren8879]

Thanks. What i was trying to show above were the conf t commands I would do on either switch. I'm thinking it should work as I had something similar working on a spare Procurve 2910 and an old CatOS 2948g-ge-tx. We didn't have a proper IOS switch available for me to test on. In my test I left the native vlan alone and couldn't get that vlan to pass traffic on the trunk. I think that had something to do with CatOS, so I migrated all those ports off to another vlan and both then spoke over the trunk. Worse comes to worse that's what I'll try to do if I have issue, but if I can avoid it initially, that's what I'd like to do.

 

[tangoseal]

Vlan1 on Cisco will never be passed over a trunk for designed security reasons. If I'm correct?

 

[Ehren8879]

Vlan1 on Cisco will never be passed over a trunk for designed security reasons. If I'm correct?

I read something that lead led me to assume this, but the describing language was more "Ciscofied". In CatOS I ran into a problem where the trunk "owner" would not pass to the other switch even if it was in the allowed vlan list. Looks like I'm going to have copy vlan 1 over to 111 or some number first.

Looks like I can do this in the global settings:

vlan dot1q tag native

 

[tangoseal]

Yes. Just remove all interfaces except for 1 of your choice from VLAN 1 and place them in VLAN whatever you want. That will give you 23 ports in VLAN 111 and only 1 management port in VLAN1. Of course on Cisco you always have a console port so you can even remove all 24 interfaces from 1 and place them in 111.

 

[Ehren8879]

I seem to be having success after plugging in

switchport trunk allowed vlan 1, 122 (on the trunk interface)

and

vlan dot1q tag native (globally)