Hello, I have the reverse proxy config as: cache_peer 175.6.1.216 parent 80 0 no-query originserver name=caiyuan acl resdomain dstdomain www.52caiyuan.com www.52huayuan.cn 52caiyuan.com 52huayuan.cn huayuan.52caiyuan.com cache_peer_access caiyuan allow resdomain When accessing to the cache, the domains www.52caiyuan.com and 52caiyuan.com work fine. But huayuan.52caiyuan.com got failed, the cache.log says: 2013/04/28 16:36:13| Failed to select source for 'http://huayuan.52caiyuan.com/' 2013/04/28 16:36:13| always_direct = 0 2013/04/28 16:36:13| never_direct = 1 2013/04/28 16:36:13| timedout = 0 For the same originserver, why some domains work but some not? The squid and OS version: Squid Cache: Version 3.1.6 Debian GNU/Linux 6.0 (apt-get install squid3) Can you help? thanks.