Squid has been updated to 3.1, and now provides native IPv6 support. The configuration file /etc/squid/squid.conf has been significantly shortened; the configuration options for Squid 3.1 have changed and are not entirely backwards compatible with some older versions. For complete details on configuration and other changes, please refer to the Squid 3.1 release notes: http://www.squid-cache.org/Versions/v3/3.1/RELEASENOTES.html.

Squid provides the ability to authenticate users via ncsa_auth and pam_auth helpers. The permissions of these helpers has changed in Red Hat Enterprise Linux 6. Previous releases enabled the setuid flag for the ncsa_auth and pam_auth, as elevated privileges were needed to access system files needed for authentication. Now, in Red Hat Enterprise Linux 6, Squid does not require the setting of the setuid flag for these helpers. This change has been made because of the security risks present when running setuid flags. Normal functionality has been maintained without setting these flags.