D315 - Network Commands

nslookup

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

ARP

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

finger (Linux)

Displays info about a user on a remote system

nmap

Scans network for hosts and open ports

tcpdump

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

telnet/ssh

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

ping

Tests connectivity to other hosts using ICMP

ipconfig (Windows)

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

ifconfig (Linux)

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

traceroute/tracert

Traces route an IP packet takes

tracepath (Linux)

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

netstat

Displays info about active ports and their state.

dig (domain information groper)

Used to query DNS (Linux)

whois (Linux)

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)

TFTP (Trivial File Transfer Protocol)

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