Today we bought a new network switch for work. It’s a managed switch and provides a few different ways you can configure it, including telnet, SSH and a web interface. It’s a Cisco/Linksys SRW2024, which is part of Cisco’s small business networking equipment offering.

I’m configuring it to have two VLANs; one for regular IP traffic and the other for our iSCSI network. I managed to lock myself out of the web interface by assigning all the ports to one of the two VLANs I’d created, and not leaving any ports attached to the default VLAN. This default VLAN had the management IP is attached to it.

Thankfully my new Acer Aspire X1800 desktop (which by the way, for $398 is a totally awesome Ubuntu desktop) has a COM port, so I connected up the serial cable and used screen to bring up a console connection:

screen /dev/ttyS0 38400

With this I could log in, then access the lcli command to give me a more meaningful console.

srw2024# configure
srw2024(config)# interface ethernet g24
srw2024(config-if)# switchport access vlan 1
srw2024(config-if)# exit
srw2024(config)# exit
srw2024# show vlan

Vlan       Name                   Ports                Type     Authorization
---- ----------------- --------------------------- ------------ -------------
 1           1                 g24,ch(1-8)            other       Required
 2         DATA               g(1-7,13-20)          permanent     Required
 3         ISCSI              g(9-12,21-23)         permanent     Required    

srw2024#

With that I had successfully removed the port from the ISCSI VLAN and replaced it into the default VLAN, making the web management console available.

I’ve never played around with Cisco gear before, but I suspect that this is similar to how IOS works.

I was happy that, even without any IOS experience, I was able to dig about inside the switch and get it back to being usable again. Now to try and attach g24 to multiple VLANs.