Have you tried unplugging the network cables and see if that resets the LAN connections?
If that does not work try plugging into system 0 directly on LAN 2 and see if you can connect.
If that does not fix it sometimes the old 2400/SV8500/SV9500 systems need to be powered down completely and restarted. Power off reset. The bad part is you can't do a graceful shut down.
To reset hold down the power button on the CPU. It is to the left of the Compact Flash. If a dual system shut both of them off.
Once it is down shut off both power supplies to the CPUs. Then power off the TSW and all PIMs in order 0-7
Wait the normal minute or 2 and then restart
Turn on the TSW and PIMs in order then power on the CPUs
Hope for the best. If that works follow it up with a backup of the database and then a graceful reset of the CPU. (power off reset again)
If that failed to work you need to put it into off line mode (system will reboot and all call processing will stop)
Mode switch piano key 1 "On"
This sets the default IP Address on the CPU Lan 1 to 192.168.0.2/24
From there you can access the telephony Server Maintenance Menu by directly connecting to LAN 1. (one Cpu at a time)
You should be able to see the addresses.
if that fails you just might need to flash the compact flash cards and reload a backup.
*** one more tidbit ****
Sometimes on a reset a CPU might not boot. It will look like it there is no power going to it. You will think the CPU is shot. Fear not there is a simple fix.
Power off the CPU. Remove the CPU and remove the memory. Wait with the memory out of the CPU for a full 5 minutes.
Reinstall the memory and put it back into the CPU. Power the system on and it should boot.
That one bit me once. I though the CPU had died. Bob at NTAC helped me get that one fixed.
Good luck
There are 10 kinds of people in the World.
Those that understand Binary and those that don't.