D315 - Network Commands

tcpdump

Displays TCP/IP packets being transmitted over network; form of protocol analyzer (sniffer); shows packet contents in human language

ipconfig

IP, subnet mask, and default gateway for each network adapter. /all will show more info.

ifconfig

Configure kernel network interfaces (make changes); shows IP, subnet mask, gateway, MAC.

traceroute/tracert

Traces route an IP packet takes

dig (domain information groper)

Used to query DNS (Linux)

whois

Used to look up owner of domain or block of IP addresses

route(print)

Used to display current route tables on a host; add/remove routes

SCP (Secure Copy Protocol)

Used to copy files between servers using SSH

FTP (File Transfer Protocol)

Copies file from one host to another host (unencrypted)

nmap

Scans network for hosts and open ports

ping

Tests connectivity to other hosts using ICMP

tracepath

Displays path taken by a packet to destination (can be used by any user)

ARP

Displays IP to MAC address mappings for hosts discovered in cache; can add, remove, or modify entries.

netstat

Displays info about active ports and their state.

nslookup

Used to query DNS to find IP addresses and domain name mappings (Windows)

TFTP (Trivial File Transfer Protocol)

Transfers a file from client to server (and vice versa) using UDP; used on local networks

finger

Displays info about a user on a remote system

telnet/ssh

Allows a user to manage accounts and devices remotely. SSH = encrypted; telnet = unencrypted