I have a debian box running squid in an active directory environment. The windows users dont have to provide a username/password to browse the net via squid as NTLM_auth is used with the Domain Controller.

However when the DC is offline ntlm authentication doesn't work so the users get prompted for a username/password. What I would like to do instead is allow all access when the DC is not responding or alternatively is there a way to cache the credentials? it would be rare for a new user to connect that isn't already connected while the DC is down?

At the moment if I know the DC is going to be down I uncomment a rule which allows full access to the local subnet but I would like something a bit smarter any ideas?

My configuration is based on this.