User:Saul/networking

Useful Commands

General

# Ping with a payload of 500 bytes 3 times
ping -s 500 -c 3 <HOSTNAME>

# Traceroute (UDP) to show a path to HOSTNAME
traceroute <HOSTNAME>

# Traceroute (ICMP) to show a path to HOSTNAME
traceroute -I <HOSTNAME>

# Traceroute (TCP) to show a path to HOSTNAME
traceroute -T <HOSTNAME>
# Alternatively
tcptraceroute <HOSTNAME>

DNS

# Resolve hostname to ip address where type = {A, AAAA, MX, NS...}
dig <TYPE> <HOSTNAME>

# Reverse dns lookup
dig -x <ADDRESS>

# Lookup using host
host <HOSTNAME or ADDRESS>

# Find who is responsible for a subnet.
whois <ADDRESS>

ip

# Show configured interfaces
ip address show

# Show info for the interface IFACE
ip address show dev <IFACE>

# Show configured routes
ip route show
# Alternative
netstat -rn

# Add a static route
ip route add <NETWORK>/<MASK> via <ROUTER>

# Add a default route
ip route add default via <ROUTER>
# Alternatively use 0.0.0.0/0 instead of default

# Add a direct route through an interface
ip route add <NETWORK>/<MASK> dev <IFACE>

# Delete a route from the routing table
ip route delete <NETWORK>/<MASK> dev <IFACE>

tcpdump

tcpdump is the command line alternative to the GUI Wireshark.

# Capture packets on an interface.
tcpdump -i <IFACE>

# Write capture to a file
tcpdump -i <IFACE> -w <FILENAME>

# Read a capture file
tcpdump -r <FILENAME>