Interview Questions.

Question 1. What Is Proxy Server And Why It Is Used ?

Answer :

A proxy server presents Internet access to different users at equal time i.E with the aid of sharing a single Internet connection. A excellent proxy server also gives for caching of the requests, which helps to get entry to statistics from nearby resources as an alternative fetching the information from web therefore decreasing get right of entry to time and bandwidth.

Question 2. What Is Squid And Its Features ?

Answer :

Squid is proxy server for UNIX like working system, A Squid proxy server filters Web site visitors and caches often accessed files. A proxy server limits Internet bandwidth usage, accelerates Web get admission to, and lets you filter URLs. Centrally blockading commercials and threatening downloads is cost effective and transparent for the cease user. Squid is a excessive in keeping with-formance implementation of a loose Open-Source, complete-featured proxy caching server.

Linux Interview Questions
Question 3. What Is The Default Configuration File Of Squid ?

Answer :

‘/etc/squid/squid.Conf‘ is the default configuration report of Squid.

Question 4. What Is The Default Port Of Squid And How To Change It ?

Answer :

Default port of squid is 3128 and we will alternate the default port by using the editing the record /and so forth/squid/squid.Conf:

http_port 3128

Change this port in keeping with your setup. After modifying the record one ought to restart the squid service.

Linux Tutorial
Question 5. How To Restart The Squid Service In Centos And Rhel?

Answer :

Service squid restart or /and so forth/init.D/squid restart

Exchange Server 2010 Interview Questions
Question 6. What Are The Different Filters That We Can Apply Using Squid ?

Answer :

Some of the filters are listed beneath :

domains of consumer or server
IP subnets of consumer or server
URL path
Full URL such as parameters
key phrases
ports
protocols: HTTP, FTP
techniques: GET, POST, HEAD, CONNECT
Question 7. What Is Acl In Squid ?

Answer :

ACL stands for Access Control List , using ACL get admission to to internet may be managed  in phrases of access all through specific time c language, caching, get entry to to specific or organization of web sites, and many others.Squid access control has two one of a kind additives i.E. ACL elements and get entry to list. An get entry to listing infact allows or deny the get entry to to the service.

Groupware servers Interview Questions
Question 8. What Are The Important Acl Elements In Squid ?

Answer :

A few vital type of ACL elements are listed below:

src : Source i.E. Customer’s IP addresses

dst : Destination i.E. Server’s IP addresses

srcdomain : Source i.E. Customer’s area name

dstdomain : Destination i.E. Server’s domain call

time : Time of day and day of week

url_regex : URL normal expression sample matching

urlpath_regex: URL-route normal expression pattern matching, leaves out the protocol and hostname

proxy_auth : User authentication via outside processes

maxconn : Maximum quantity of connections restriction from a unmarried customer IP deal with

To practice the controls, one has to first outline set of ACL and then follow policies on them. The format of an ACL announcement is

acl acl_element_name type_of_acl_element values_to_acl

Question 9. Write A Rule Allowing Only Selected Machines To Have Access To The Internet ?

Answer :

Edit the config record /and so on/squid/squid.Conf :

acl allowed_clients src 192.168.1.10 192.168.1.20 192.168.1.30

http_access permit allowed_clients

http_access deny !Allowed_clients

Above rule will allow most effective device whose IPs are 192.168.1.10,192.168.1.20 & 192.168.1.30 to have get entry to to Internet and the relaxation of IP addresses (no longer indexed ) are denied the service. After enhancing the report don’t neglect to restart the squid service.

Samba Server Interview Questions
Question 10. Allow Internet Access During Particular Period Of Time ?

Answer :

Edit the file ‘/and many others/squid/squid.Conf’ and upload the beneath guidelines :

acl allowed_clients src 192.168.1.1/255.255.255.Zero

acl regular_days time MTWHF 10:00-16:00

http_access permit allowed_clients regular_days

http_access deny allowed_clients

This will allow the get entry to to all the customers in network 192.168.1.1 to get entry to the net from Monday to Friday from 10:00am to four:00 pm.

Question 11. How To Enable Multiple Time Internet Access To Different Clients In Squid ?

Answer :

Edit the config file and add below guidelines :

acl hosts1 src192.168.1.10

acl hosts2 src 192.168.1.20

acl hosts3 src 192.168.1.30

acl daybreak 10:00-thirteen:00

acl lunch time thirteen:30-14:30

acl evening time 15:00-18:00

http_access allow host1 morning

http_access allow host1 evening

http_access allow host2 lunch

http_access permit host3 nighttime

http_access deny all

The above rule will permit host1 access at some stage in each morning in addition to evening hours; in which as host2 and host3 may be allowed get admission to best during lunch and evening hours respectively.

Mail Server Interview Questions
Question 12. How To Block Websites Using Squid ?

Answer :

Squid can save you the access to a selected web site or to websites which include a selected phrase. This may be implemented via adding the beneath rules inside the ‘/etc/squid/squid.Conf’ file.

Acl allowed_clients src 192.168.1.1/255.255.255.0

acl banned_sites url_regex "/and many others/banned.Listing"

http_access deny banned_sites

http_access allow allowed_clients

Create a document /and so forth/banned.Listing , add all of the web sites that you need to block.

Linux Interview Questions
Question 13. How To Limit The Number Of Connections From A Client Machine In Squid ?

Answer :

Squid can restrict number the of connections from the consumer gadget and this is viable via the maxconn element. To use this selection, client_db feature should be enabled first.

Acl mynetwork 192.168.1.1/255.255.255.Zero

acl numconn maxconn five

http_access deny mynetwork numconn

maxconn ACL makes use of less-than evaluation. This ACL is matched while the variety of connections is extra than the required value. This is the primary cause for which this ACL isn't used with the http_access permit rule.

Question 14. What Is Reverse Proxy ?

Answer :

A reverse proxy is a kind of proxy server or ‘webserver acceleration’ (the use of http_port 80 accel vhost) , in this sort of proxy server , the cache serves an infinite variety of clients for a constrained wide variety of or simply one net server. 

Question 15. What Is Transparent Proxy ?

Answer :

Transparent proxy is a form of proxy server where customers are not aware that their requests are processed thru the proxy. The important benefit of placing transparent proxy is that  machine admins do not must setup up individual browsers to paintings with proxies, squid will transparently choose up the suitable packets and cache requests.

Qmail Interview Questions
Question sixteen. How To Clear Squid Cache ?

Answer :

To clean the squid cache , first prevent the squid carrier and run underneath command :

# service squid prevent

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

Not create swap directories :

# squid –z

Question 17. How To Check Live Running Logs Of Squid ?

Answer :

To see the stay logs of squid use the underneath command :

# tailf /var/log/squid/access.Log

Exchange Server 2007 Interview Questions