3560 VLAN Problem

[Narsman3000]

This may seems pretty simple.............it is, but I'm having a heck of a time getting it to work.

I have a 3560 switch that has been factory defaulted. It is connecting a small network of workstations and servers (including DHCP server). All 48 ports are in VLAN 1 and I have Gb1 setup as trunk to connect to firewall to Internet. Everything works.

Here is my issue....I would like to change all of the ports from VLAN 1 to another VLAN number (the number doesn't matter). I use CNA to administer to the switch. When I go into CNA and change the VLAN on all of the ports, (ie from 1 to 99) and APPLY, all connectivity is lost. I thought perhaps it might take a few minutes to process, so I waited 10 minutes and still no joy.

I changed the VLAN back to 1 and within a couple of minutes, everything worked again. 

Any help would be appreciated.

[mkazam001]

perhaps your effecting the trunk port config when you make the change?

ensure all vlans are allowed across the trunk link, including 99.

you could console to switch & do it:

conf t

 vlan 99

  name test-vlan

  exit

 interface range g1/0/1 - 10

  switchport mode access

  switchport access vlan 99

regards, mk

[Narsman3000]

Thanks for the quick response.

The Gi0/1 port is set as 802.1Q Trunk and VLANs set to ALL.

I use CNA and highlight ports 1 - 48 and click Modify and change the Static-Access VLAN number to 99. Then OK and Apply.

Still no joy.

Does that set the switchport mode access & switchport access or does that need to be done through CLI?

[gaston.benitez · Accepted solution]

Hi

Since you change the vlan assignement on the switch, do you have vlan 99 or the new vlan created on the firewall? Vlan 1 working as native vlan in a switch may be passing to the firewall untagged. When you configure the new vlan, Firewall will be receiving vlan 1 untagged and a new vlan with a tag that may not recognize.

You can try to only apply the changes not to all but to a portion of the ports and see the effects.

If this works, may be the issue could be pressent on the FW.

BR

Gaston

[Narsman3000]

Thanks! That was the piece I was missing. Everything is running great now.

[gaston.benitez]

I am glad to hear that

thanks

BR

Gaston