Solved: 2900 switch 'without' configuration

ffurholm · ‎01-02-2004

How do I access a 2900 switch, which has lost it's configuration,

- got the hostname 'Switch',

- got a new IP address from the DHCP server

all this can be seen by 'show cdp neighbor detail' from the connected router.

But it has lost it's passwords, so a telnet will respond with 'Password required, but none set'.

How do I recover from that, without driving to the site ?

ffur@danskebank.dk

Craig Norborg · ‎01-02-2004

Actually it somewhat depends on what IOS you have on it. If its a somewhat old IOS, you can "break" into the switch via the HTTP interface. First try using HTTP to gain access to the switch, if it brings up a web page, you might be in luck. After that, you basically need to emulate the URL necessary to do what you want. For the "level", I put 16 in here, sometimes a higher number (like 99) works better.

http://IPADDR/level/16/configure/-/line

Other than this, you could also try the "Cisco Security Check" tool in the solarwinds.net toolset. It can sometimes break into a switch/router if the IOS is old enough and allow you to upload a config.

Hope this helps a bit. These techniques have worked pretty well for me in recovering lost switches.

View solution in original post

skarundi · ‎01-02-2004

unfortunately you cannot recover without console access. If you see the message "password required, but none set" means that the telnet feature is active but no telnet password as been configured. There is no way to work around this.

With Cisco IOS, you must have a telnet password in order to telnet to a switch or router.

Example:

line vty 0 4

password cisco1234 <====

bflanary · ‎01-02-2004

Hi,

Unless you have remote access to the console port (ie. through modem connection/termserver) you will have to console into the switch and configure a telnet password in order to connect.

Documented here:

http://www.cisco.com/univercd/cc/td/doc/product/lan/c2900xl/29_35wc6/scg/swadmin.htm#xtocid5

Craig Norborg · ‎01-02-2004

Actually it somewhat depends on what IOS you have on it. If its a somewhat old IOS, you can "break" into the switch via the HTTP interface. First try using HTTP to gain access to the switch, if it brings up a web page, you might be in luck. After that, you basically need to emulate the URL necessary to do what you want. For the "level", I put 16 in here, sometimes a higher number (like 99) works better.

http://IPADDR/level/16/configure/-/line

Other than this, you could also try the "Cisco Security Check" tool in the solarwinds.net toolset. It can sometimes break into a switch/router if the IOS is old enough and allow you to upload a config.

Hope this helps a bit. These techniques have worked pretty well for me in recovering lost switches.

ffurholm · ‎01-05-2004

Hi

This solved my problem - thanks.

Do you know where I can find some information regarding this URL ?

Thanks again

ffur@danskebank.dk