Squid Server Interview Questions And Answers for linux admin

Q: - On Which port Proxy server work ? Can we change proxy server port ?

By default proxy server runs on 3128 port. yes we can change proxy server port.

vi /etc/squid/squid.conf

http_port 3128

Q: - How to block Some domains by Squid server ?

Make a file

vi /etc/squid/bad_domains

.xxx.com
.abcd.com
.sexy.com

Now make following changes in Squid.conf file

acl BAD_DOMAINS dstdom_regex -i "/etc/squid/bad_domains"
http_access deny BAD_DOMAINS

Q: - How to clear Cache in Squid proxy? 
Firstly stop squid server.

service squid stop

rm -rf /var/lib/squid/cache/*

squid -z

Q: - How to restart squid server ?

service squid restart

Q: - What is the name of main configuration file for Squid server ?

/etc/squid/squid.conf

Q: - How to restrict web access by Time ?

acl MY_TIME time M T W H F 9:00-17:00

http_access allow MY_TIME

Q: - What is Squid ?

SQUID is a webcache and proxy server for Linux and UNIX.
Users configure their web browsers to use the Squid proxy server instead of going to the web directly. The Squid server then checks its web cache for the web information requested by the user. It will return any matching information that finds in its cache, and if not, it will go to the web to find it on behalf of the user. Once it finds the information, it will populate its cache with it and also forward it to the user's web browser. 

Q: - What is location of Cache directories for SQUID ?

/var/spool/squid

Q: - What this command "squid -z" will do ?

This command will create cache directories.

Q: - Explain "maximum_object_size" directive?

It defines maximum size for objects to be stored in the disk.The value are specified in kilobytes, and the default is 4MB.

Q: - Explain "cache_dir" directive?

This is used to define cache directory, its path, type and size.

cache_dir Type Directory-Name Mbytes Level1 Level2

Q: - What is ufs?

ufs is a squid storage format.