Hi, I discovered the problem was because I hadn't specified 'visible_hostname' option. After I set this option to my m/c hostname it doesn't give this error any more. But I don't understand why does one HAS TO specify this since according to below statement in "squid.conf" file
# TAG: visible_hostname
# If you want to present a special hostname in error messages, etc,
# then define this. Otherwise, the return value of gethostname()
# will be used. If you have multiple caches in a cluster and
# get errors about IP-forwarding you must set them to have individual
# names with this setting.
It doesn't seem necessary if gethistname() can get it.
Can anyone please explain this to me.