We have a remote POP that consists of a Cisco 2600 router, and a Lucent Portmaster 3
Normally to make any configuration changes to the remote pop, we would just telnet in and do the changes.
However we needed some sort of backup method that would allow us to get access to the Cisco in case we ever made a "wrong" change and stuffed up the routing etc thus preventing telnet access.
We chose to hook the console port of the PM3 to the Console port of the Cisco.
So in the event of a routing problem, we could dial into the PM3 and then open a reverse telnet session to the Cisco via this console cable.
The reverse telnet session would give us normal access to the cisco to allow us to fix whatever mistake we just made in the routing config.
Setup hardcoded username/password on cisco for console port
aaa authentication login STORE_LOCAL local ! username conun password conpw ! line con 0 location ** CONSOLE CABLE speed 115200 exec-timeout 0 0 login authentication STORE_LOCAL transport input none flow-control hardware
Make sure dip switch 1 is down on back of portmaster
Wire up the cable.
The cable we used is the blue console cable and DB9 adapter that ships with cisco routers. Plus we had to use a 9-25 pin adapter to make the cable fit the pm3 console port. Heres what the final cable looks like[cisco console port]--[blue RJ45 cisco cable]--[cisco RJ45-DB9F adapter]--[9pinM 25pinM adapt]--[Pm3 C0 port]
Configure the c0 port on the pm3
PM3> set c0 speed 1 115200 PM3> set c0 speed 2 115200 PM3> set c0 speed 3 115200 PM3> set c0 xon off PM3> set c0 over xon off PM3> set c0 rts on PM3> set c0 device /dev/network PM3> set c0 service_device telnet 6000 PM3> set c0 modem off PM3> reset c0
make sure pm3 is configured to allow !root login via serial
PM3> set serial-admin on
If the PM3 ethernet address cannot be reached via the internet :
dial into the portmaster with a modem login as !root
Open a reverse telnet session to the C0 porttelnet xxx.xxx.xxx.xxx 6000
Cisco login prompt should appear
username is conun
password is conpw
Then you should have access to the the Cisco's command prompt!