Networking Tools

Connection

curl/wget

Used for downloading files. Depending on how the website redirects, curl or wget may be easier to use.

ping

Used to check to see if a host is up by sending ICMP packets.

traceroute

Shows the different connections established between you and the destination. Useful for debuging routing issues.

DNS

DIG

Prints out DNS records for a specified domain

Packet Capture

tcpdump

Dumps all TCP packets to output. Useful for a quick way to confirm that packets are indeed flowing.

wireshark

Extremely useful tool for analyzing packet captures, does protocol parsing among other things.

Ports

nmap

Port scanner, can tell you what ports are open, as well as what protocol they are using.