Folks, imagine I have a 3750 in production. spanningtree-mode is pvst.
Ports fa1/0/1-fa/0/47 are assigned to Vlan 30. I see a SVI for VLan 30, IP=10.200.1.1/24. Vlan 30 interface is up/up.
vlan 1 is down/down.
Then on port fa1/0/48 on the 3750, I need to connect a terminal server with pre-configured IP=192.168.1.1/24.
Basically from the 3750 I need to telnet to 192.168.1.1 and then configure the terminal server with whatever routable IP I want.
Is this possible without crashing the production Vlan 30?
To my knowledge so far, I should create an "interface vlan" with IP on 192.168.1.0/24 network in order to be able to establish connectivity with the terminal server on port fa1/0/48 from the 3750, right? Then I would assign the port fa1/0/48 to a new Vlan, "vlan 192".
My observation and concern is that if I create such SVI "int vlan 192", immediately Vlan 30 could get shut down due to spanning-tree, correct?
I do not have a PC on site which could let me connect to the same VLAN and access the terminal server from there.
Please let me know if I can make this operation work using the Cisco switch.
Creating a new VLAN 192 on your 3750 will not force the existing VLAN 30 to be shut down or blocked due to the STP. Right because of PVST, each VLAN can be individually created, deleted and its state changed without influencing the state in other VLANs - that's a part of what the Per-VLAN STP is about.
However, if you are still concerned about creating a new VLAN, I suggest adding a secondary IP address on the SVI for VLAN30, like,
ip address 192.168.1.254 255.255.255.0 secondary
and assigning the port Fa1/0/48 to VLAN 30 as well. Now you can telnet to 192.168.1.1 and change its settings. Then, according to your needs, you can remove the secondary IP from your VLAN 30 SVI.