There can be a few occasions where you may need to manually purge the local DNS cache and/or the actual web cache of a Blue Coat ProxySG appliance. While both the DNS cache and web cache will eventually age out it can be helpful to sometimes speed up the process by flushing/purging the DNS and web cache.

While this can all be done from the web interface I generally prefer the CLI (if available). The Blue Coat ProxySG appliances that I managed are setup for SSH access you may need to confirm that SSH is enabled (telnet might be enabled).

Let’s start by connecting to the BlueCoat ProxySG appliance (proxysg.acme.org);

[root@linuxhost etc]# ssh -l admin proxysg.acme.org
admin@proxysg.acme.org's password:

proxysg.acme.org - Blue Coat SG510 Series>

Once we’re connected we need to go into privledged mode to issue the commands;

proxysg.acme.org - Blue Coat SG510 Series>enable
Enable Password:

Now that we’re in privledged mode we can clear the web content cache with the following command;

proxysg.acme.org - Blue Coat SG510 Series#clear-cache
ok

And to clear the DNS cache we can use the following command;

proxysg.acme.org - Blue Coat SG510 Series#purge-dns-cache
ok

And don’t forget to logout when you’re all done.

proxysg.acme.org - Blue Coat SG510 Series#exit
Connection to proxysg.acme.org closed.

Cheers!