Multiple VLANS on Cisco 2950

[shannon.jones]

I have a small wireless ISP and all my customers have public static IPs.  I am adding a /24 of new addresses to my network and need to have multiple VLANS on my 2950 port which is just an access port currently.  Right now the current IPs are on VLAN 1 along with my client antennas that I manage which are on private statics.  I want to add a VLAN (400 for example) but also need to have access to the old addresses and manage my client antennas.  Is there a way to do this?

Thanks you!

[Richard Burts]

To have multiple VLANs on a port on a 2950 can be accomplished by configuring the port as a trunk port. So that is quite achievable. Whether it will really be the solution that works depends on some things that you have not told us. So far you have mentioned a single 2950 port as an access port. What is connected on this port and what will be the impact on the connected device if you assign multiple VLANs on that port? Where will VLAN 400 be? What ports will belong to VLAN 400? What will do the routing for VLAN 400? If you can tell us these things then we may be able to assess how well this would be as a solution for your requirements.

HTH

Rick

[shannon.jones]

Thank you Rick for the reply.  I have quite a few 2950s throughout my network and Vlan 400 will be just one of the vlans on my network.  The current public static IPs that my customers have will go back to our upstream provider and will be replaced by our own IPs now that we will be running BGP.  Most of my customers connect directly into a port on our cisco switches so it will be an easy migration (change customer IP then change the Vlan on port). However, there are some that connect into a wireless AP before the switch. For example, Cisco switch--sector wireless AP-- customer antennas--customer firewall/router with Static IP.  Some of my sector antennas have 15 customers and trying to coordinate them all at the same time to switch IP addresses will be a nightmare.  Vlan 400 will be routed by our cisco router close to the headend of our network.  After the IPs have been migrated ill still need to be able to manage the antennas that will hang off the cisco port Vlan 400.  Will this work by making it a trunk?

Thanks,

[Richard Burts]

I understand the challenge in trying to change addresses, especially if 15 customers are sharing an antenna. But I do not understand how VLAN 400 will solve this challenge.

If I am understanding your situation correctly then right now you have a flat network with only VLAN 1 which means that all switch ports are access ports. If you want to create VLAN 400 and if VLAN 400 should operate on multiple switches then the ports that connect a switch to devices that need to be aware of both VLANs will need to be configured as trunks.

HTH

Rick

[JohnTylerPearce]

If you have multiple 2950s, which is sounds like you do, you could create a trunk using a different cable than the one currently connecting the switches, and create a trunk like Richard suggested. If you do this, then you can take out the cable, with hardly any downtime at all, since the trunk would also be a member of every vlan by default.

[shannon.jones]

Thank you for the help guys.  Yes we do have multiple switches and they are all trunked together.  Most of our switches are at multi tenant office buildings but some are located at tower sites where there are sector antennas that connect into the switch.  These are where I would like to have both Vlans running across so I can more easily migrate customers from the old IPs to the new ones on Vlan 400.  So if I hear you correctly we need to change it to a trunk port  which will allow us to see the old addresses on native Vlan 1 and the new ones on Vlan 400.  The antennas do not do any tagging.

Thx!