ssh tunnelling

To Create a local ssh tunnel on your machine (port 1234 – example) to the POP3 server’s port 110. You will need to be the root user to bind to “privileged” ports

ssh -f -N -L 1234:localhost:110 user@POP3_server

Test the tunnel.
telnet localhost 1234
You should see the POP3 server’s banner information.

Allow AOL Messenger in Squid

To allow AOL Instant Messenger traffic via https with Squid, change the following line in the Squid configuration file

1. vi /etc/squid/squid.conf

2. Change:
acl SSL_ports port 443 563

acl SSL_ports port 443 563 5190

3. Send the Squid process a SIGHUP or use the service command.
/sbin/service squid reload

Updating BIND default ROOT servers (

Use the BIND dig utility to retrieve a list of root name servers.

dig . ns >

Make sure to copy to the directory containing your DNS maps. Restart BIND for the changes to take effect.

The 7 Layers of OSI