Reconfigure Cisco Router 1841 with new T1 Lines - Page 2

anisha.vi · ‎05-06-2010

Hello,

I am really very much interested in Network Administration,and recently got a job in the same.We have remote locations having installed with new T1 lines, which means new circuits and new IP Space. The circuits have been delivered and are ready for us to schedule turn up with the carrier. The Cisco routers 1841 at those locations will need to be reconfigured for the new IP space associated with the circuits. Once this is complete we need to turn the service up. We are doing this remotely from the main office location. We will want to do this on a scheduled cutover with the vendor asap as the circuits havestarted billing.

IP information for the new connections has been provided for us with what we will need to swing the connections over to. Please find the attached IP information I was provided with. At the time of conversion we need to move the T1 service cable from 1 carriers demarc to the other.

As far as I know, I think I should just change the IP Address information and Subnet mask information in the Serial interface which is a T1 interface, and then change the static route information. I don't think I need to touch any other data in config file.

But the problem is when I try to change the config on the serial interface using the following I am loosing the connection with the router:

Router_1841#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router_1841(config)#int s0/0/0
Router_1841(config-if)#ip address xxx.xxx.xxx.xxx yyy.yyy.yyy.yyy

where,

xxx.xxx.xxx.xxx being the new IP address

yyy.yyy.yyy.yyy being the subnet mask

As soon as I enter this command, that is it, I am lost with the connection of router. I can connect to it only after I asksomeone at the location to reboot it.

Can someone please help me with this issue. I will be really really very helpful. Also, the vendors are in a hurry to schedule the cutover asap.

I will be very glad if someone can correct me if i am wrong, and let me know the correct way to reconfigure the routers.

Thank you very much.

Regards,

Anisha.

normanjeter · ‎05-20-2010

I like the scheduled reboot idea. I was actually unaware of that little gem of a command.

As far as the Out of band connection goes, The setupis pretty simple:

1: Pull an analog Phone line to the server room.

2: get an external 56k modem (I prefer USRobotics)

3: get a serial (db-9) to Serial (db-25) modem cable and connect to your pc's Serial Port.

4: configure the modem Using the info on this page:

http://www-tss.cisco.com/eservice/compass/common/tasks/task_verikit_configure_USRmodem.htm

5: Get a Modem cable that goes from 25-pin male to rj-45

6: Plug into AUX port

7: Add the necessary lines to your Config file:

line aux 0
login local
modem InOut
modem autoconfigure type usr_courier    <-- Replace usr_courier with whatever model you get, though the courier is a nice one to use.
transport input all
escape-character BREAK
autoselect ppp
stopbits 1
speed 115200
flowcontrol hardware


This should get you going for dialing into the modem to connect to the router while doing the changeover. Let me know if you have any questions.

Norman

anisha.vi · ‎05-20-2010

Thank you very much Norman. I will give a try with this. I will let you know if I have any questions.

Thanks & Regards,

Anisha.