TELNET:
Features:
1. Great for basic TCP port diagnosis
Task:
1. Connect to TCP ports on various hosts
•telnet 192.168.75.100 22
•telnet www.linuxcbt.com 80
Netstat:
Features:
1. Provides network connection information from /proc/net/*
Task:
1. Return useful information for various protocols
•netstat
•netstat -a - returns all protocols/sockets
•netstat -ntlp - returns all TCP LISTENERS without name resolution
•netstat -nulp - returns all UDP lISTENERS without name resolution
Note:
•netstat uses /etc/services to translate ports to names
•0.0.0.0:514 - this means that Syslog will accept traffic to any of the defined IP
addresses/interfaces on the system
• netstat -ntp - returns established connections (sockets)
• netstat -rn - returns the routing table