Wireshark is the world's foremost network protocol analyzer. It lets you see what's happening on your network at a microscopic level. It is the de facto (and often de jure) standard across many industries and educational institutions.
Decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2... (
more)
The program works with the following extensions:
bfr,
cap,
fdc,
rf5,
syc,
tpc,
erf,
tr1,
acp,
trc,
wpc,
pkt,
wpz,
enc,
5vw,
apc,
atc,
pcap,
snoop and
trace