Squid 2.6 dynamic IP host name resolving problem
 

In SQUID I have an ACL with a host "somename.no-ip.org" which looks like this:
"acl bo src somename.no-ip.org"
"http_access allow bo"

And everything works fine until the IP address (which is dynamically assigned) of the host "someone.no-ip.org" changes. And to give access to the proxy to this host I have to restart the squid server.

So my question is: How to make SQUID to auto-sense the new IP address of the host without manually restarting it?

You can't. If you rely on a dynamic IP here, you have to make sure that the IP time outs very fast (verify your TTL), which restricts the underlying name resolving library in glibc to reload the IP address.

Squid itself doesn't care.

So, there is no way to give access to my proxy server to an outside client who has a dynamically changing IP and just writing down his DNS name which is one of "no-ip.org " to my access list in squid.conf file. Any suggestions for a workaround.

You may authenticate privileged users to your web cache (see here for example). This doesn't require you to know client IPs in advance.