Cisco VPN tunnel between router and firewall will only accept “cisco” for the PSK

[annahernandez99]

Had a head scratcher today. This tunnel worked for months without issue. Both sides claim nothing changed.

After various steps and finally blowing away the entire tunnel config on the ASA side and starting fresh, comparing side by side all other things for a config on a client's router and our ASA firewall, we decided, what the hell, let's change the pre-share key (even though we had verified on both ends we matched) to something very simple on both ends.

We changed it to "cisco" and the tunnel worked fine. We tried to change it to anything else, the authentication failed. Tried another 5 letter lower case word, would not work. Change it back to "cisco" works fine. What gives?

[marce1000]

 - So the intended pre-shared key was correctly set on both platforms I guess (?) -  Also make sure that you do not suffer from volatile-effects where for instance a configuration must be 'sufficiently saved' first. If not working check and or post the logs from both platforms pointing to the issue.

 M.

[MHM Cisco World]

Hmm interest, 
I think the password-encryption in one side do this effect.
please confirm if you config such like this feature in one side.