I meant to put this post here.
I need expert help with this scenario. Switch A is CAT 3560E PoE and switch B is CAT 3750 PoE. Connectivity between these swithces are 10gb fiber and is set to trunking so vlan1 can be access on both switches. I have a firewall dzm interface that i would like to bring in to switch A port # 48 and create a vlan 2 dmz there. Then on switch B, port #48, i configure it as a vlan2. Then when I connect my laptop, i could get an IP address from DHCP on the firewall dmz interface. So, looks like trunking between switch A and B carries all vlans. So, i have a Cisco CAT 3500XL that i would like to connect to port #48 on switch B so that i could add more workstations here. However, when i connect CAT 3500xl to port #48 of CAT 3570, port number #48 is disabled. Then, I set it up as trunk port but i am no longer have access to vlan2.
Here is the worse part, while trying to troubleshoot this, suddenly all VoIP phones and connectivities were down. I do not know if me adding the 3500xl would cause this problem but it seems we had a brownout while i was troubleshooting.
Please help since this is something i've never done before.