If you're using older clients, you need to upgrade!!!! CLIP2 is no longer providing host caches, so clients like Bearshare 2.2.4 can't connect using the default servers. Time to upgrade.

FROM CLIP2:

We have discontinued our Gnutella, OpenNap, and JXTA network tracking services. Our Gnutella host cache (gnutellahosts.com:6346) and JXTA rendezvous (jxta.clip2.com:6001 & 6002) services have been discontinued as well. The Clip2 Reflector, a proxy-and-index server for Gnutella, is no longer available for download or supported, and we have discontinued our listing service for public-access Reflectors.