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Lost connection to router while copying startup config to running

mahesh18
Level 6
Level 6

Hi,

When i copy start up config to running config on my router remotely i lost the connection for few mins and when i got connection back

i saw this in logs


Apr  3 05:08:05.219 MST: %DHCP-6-ADDRESS_ASSIGN: Interface FastEthernet0/0 assig                                                                                                                               ned DHCP address 96.51.x.x, mask 255.255.252.0, ).
Apr  3 05:13:10.065 MST: %DHCP-6-ADDRESS_ASSIGN: Interface FastEthernet0/0 assig                                                                                                                               ned DHCP address 96.51.x.x, mask 255.255.252.0, hostname 2650xm

my interface fa0/0 connects to isp cable modem.

i telnet to router using public ip 96.51.x.x..

any idea why this happened?

thanks

1 Accepted Solution

Accepted Solutions

Manesh,

To reiterate, when you make changes in the running-config, the correct command is

copy run start

not

copy start run

When you copy the startup-config to running-config, the startup config may overwrite changes made in the running-config.

These changes may affect connectivity to your router. As you are obtaining the IP address via DHCP, the startup-config may have saved a different IP address from a previous instance...

It can also be due to the fact that if you type 'ip address dhcp' under the physical interface, the DHCP client may be restarted and connection to the router via this interface may be suspended until a new lease is obtained. Again, typing that command or overwriting the config with the command in it, will cause the same effect.

Regards

Edison

Please rate helpful posts.

View solution in original post

6 Replies 6

Edison Ortiz
Hall of Fame
Hall of Fame

Why would you copy your startup-config to your running-config?

The common process is to copy your running-config to startup-config.

The process performed while copying the startup-config to the running-config is similar to the process of applying configuration changes in your router.

When you apply configuration changes in your router, you run the risk of losing the connection if the parameters aren't the same as the current running-config.

Based on the ouput you've displayed, it seems your F0/0 had a different IP address stored in NVRAM obtained from DHCP than your current DHCP lease.

You need to be aware the content of the startup-config before overwriting the running-config. I suggest typing 'show start' before doing so and compare the output with 'show run'.

Regards

Edison.

Hi,

show archive config diff

is an easy way to compare running versus startup config.

See http://www.cisco.com/en/US/docs/ios/fundamentals/command/reference/cf_s1.html#wp1166696

BR,

Milan

Hi,

thanks for reply the config is same.

is there any other reason you might think of?

mahesh

Hi Edison,

sorry for late reply

i did copy startup to running as i did some change on running  config.

also my IP address connected to fa0/0 which i get from isp is same.it did not change.

thanks for reply

mahesh

Manesh,

To reiterate, when you make changes in the running-config, the correct command is

copy run start

not

copy start run

When you copy the startup-config to running-config, the startup config may overwrite changes made in the running-config.

These changes may affect connectivity to your router. As you are obtaining the IP address via DHCP, the startup-config may have saved a different IP address from a previous instance...

It can also be due to the fact that if you type 'ip address dhcp' under the physical interface, the DHCP client may be restarted and connection to the router via this interface may be suspended until a new lease is obtained. Again, typing that command or overwriting the config with the command in it, will cause the same effect.

Regards

Edison

Please rate helpful posts.

Hi Edsion

Thanks for  good explanation

Regards

Mahesh

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