Changes in version 2.3 Polar Bear:

Bug fix: policing configuration changes for subscribers having several IPs did not work.

Netflow shaping was added to avoid losses on weak collectors.

Update manual

Do not update Linux kernel to the latest version kernel-2.6.32-431.29.2 or above. This kernel is not binary compatible with Kernel ABI. The network driver can not be loaded after this update. In case you made this update - please configure grab loader to load the previous version while solving the problem1) Set the parameter default=1 in the file /etc/grub.conf .

Check what's new in previous version.