The Vlan Blues :)p

joe48184

Hello folks..
I'm studying for the ICND1 test and I'm working a bit with Vlan's, or trying to at least. I was playing around with 2 2950's using Vlan 1 learning about VTP, spanning tree and either channels.

I got the idea to create an additional Vlan on both switch's called Vlan 2 and trunk / either channel them, it worked on vlan one, why not vlan 2.

The problem thats got me baffled is that every time I assign an ip address to Vlan 2, Vlan 1 goes administrativly down. When I bring it back up, Vlan 2 goes down. Vlan one is on the 192.168.0.0/24 and Vlan 2 is on the 10.0.0.0/8. Doesn't seem to matter what ip address I use only one vlan will stay up at a time.

I know I'm missing something.... I mean it all worked fime with the default vlan, why not with 2?

Thanks folks.

/usr

I think you're confusing your concepts and hardware.

VLAN 1 on your switch doesn't really have an IP address. The IP you assign under vlan 1 is only for administrative purposes on those 2950 switches. You don't have to "enable" any other VLAN's you create, simply creating them and adding interfaces to them is fine.

VLAN's are virtual and do not have an IP address themselves, they are just identifiers of separate broadcast domains and subnets.

Are you just trying to setup those links as an Etherchannel trunk for VLAN 1 and 2?

IMO, just leave the Etherchannel out of it for now and create a trunk link for both VLAN's. Get that working and you'll have solved your issue.

joe48184

wow, I'm really lost then.. I thought you would Vlan a switch to have 2 seperate networks.. like the 10 net on one side and the 192 on the other.
That way you could test on one half with out impacting the other half.

I'm new to networking so I could be very wrong.

Thanks for the reply.

/usr

Yeah...I'm not really sure what to say other than you're way off.

I'd hold off on the labs and focus more on the network theory first. Read up a bit more on VLAN's.

jason_lunde

joe48184 wrote: »

wow, I'm really lost then.. I thought you would Vlan a switch to have 2 seperate networks.. like the 10 net on one side and the 192 on the other.
That way you could test on one half with out impacting the other half.

I'm new to networking so I could be very wrong.

Thanks for the reply.

A 2950 is a layer two switch, if you had a layer 3 switch such as a 3550, 3560, or 3750, what you are trying to do would be ok. But on that particular switch you can have only one vlan interface up at a time, and it is for management purposes.

joe48184

jason_lunde wrote: »

A 2950 is a layer two switch, if you had a layer 3 switch such as a 3550, 3560, or 3750, what you are trying to do would be ok. But on that particular switch you can have only one vlan interface up at a time, and it is for management purposes.

Ahh.. now I got it.. So I was right and wrong.. I had it working with out the vlan but with it, it caused issues.. the age of the hardware and more importantly the fact its limited to being a layer two is the issue.

Thanks, that helped alot.