[squid-users] 101 network unreachable

[salah khater]

Hi ALL

I get this error in the client browser.
error: 101 network unreachable
and in squid access log 
TCP_MISS/503 3761 GET http://www.debian.org/ - DIRECT/www.debian.org text/html

is this related to ipv6 sites? or?

squid 3.1.6