COMP9331 - lab1

Ping
to check connectivitiy to a host
$ ping host

Traceroute
used to discover the routes that packets actually take when traveling to their destination.
$ traceroute host

Telnet(obsolete)
used to connect form one host to another (remote login) via the internet network

SSH
allows establishing a secure channel between a local and a remote computer.
 *ssh supports terminal protocols is typically used for remote administration of the SSH server computer via terminal console. it is used as an alternative to telnet. 
 $ ssh -l username hostname
 $ ssh username@hostname
 
ifconfig
used to assign an address to a network interface and to configure or display the current network interface configuration information.
*Note: the directory /sbin is not the path of a typical ser. So you may have to type /sbin/ifconfig

netstat
allos to print the various data related to the network configuration of a station.
Option -i allows to print the state of the network interfaces

Option -r displays the kernel routing table

Option -n makes netsate print address as dotted quad IP numbers rather than the symbolic host and network names

netpref
provides test for both unidirectional throughput and end-to-end latency. 
The calculation of these parameters is based on measuring the time necessary to transmit messages of fixed size by TCP.
$ netperf host [message_size [count]]

nslookup, dig, host
nslookup is used to find out the corresponding IP address of a host name(
$ nslookup redhat.com

dig is similar to nslookup, it is a tool for querying DNS nameservers for information about host address,
mail exchanges, nameservers, and related information.
More Info: https://www.thegeekstuff.com/2012/02/dig-command-examples/
$ dig host
HEADER:
QUESTION SECTION:
ANSWER SECTION:
AUTHORITY SECTION:
ADDITIONAL SECTION:

Display particular section only
+nocomments; +noauthority, +noadditional, +nostats, +noanswer
e.g. only show the answer section
$ dig rehad.com +noall +answer

Query MX records using -t MX
$ dig redhat.com MX +noall +answer
$ dig -t MX redhat.com +noall +answer

Query NS Records using -t NS
$ dig redhat.com NS +noall +answer
$ dig -t NS redhat.com +noall +answer

View all DNS Records TYPES(A, MX, NS, etc) using dig -t ANY
$ dig redhat.com ANY +noall +answer
$ dig -t ANY redhat.com +noall +answer

View short Output using +short
$ dig redhat.com +short
$ dig redhat.com ns +short

DNS Reverse Look-up Using -x
$ dig -x 209.132.183.81 +short

Bluk DNS Query Using dig -f
1. create a txx file
$ vi names.txt
  redhat.com
  centos.org
2.using dig -f
$ dig -f names.txt +noall +answer
$ dig -f names.txt MX +noall +answer
Other Methods:
$ dig redhat.com +noall +answer centos.org ns +noall +answer

grep
the grep utility searches text files for a pattern and prints all lines that contain that pattern
if you want to search for a fixed string you should rather use fgrep