Deb of the Day: conntrack

So I was trying (unsuccessfully) to get pyctd installed and was looking doing the dselect dependency dance (yeah, I'm old school) and I ran across conntrack

Being spoiled with PF (or pfctl actually) I always wondered how you could do this in Linux.

# conntrack -E
[UPDATE] tcp 6 30 LAST_ACK src=192.168.2.170 dst=72.14.205.83 sport=52241 dport=80 packets=9 bytes=2262 src=72.14.205.83 dst=24.136.2.99 sport=80 dport=52241 packets=7 bytes=606
[UPDATE] tcp 6 120 TIME_WAIT src=192.168.2.170 dst=72.14.205.83 sport=52241 dport=80 packets=9 bytes=2262 src=72.14.205.83 dst=24.136.2.99 sport=80 dport=52241 packets=8 bytes=658
[NEW] tcp 6 120 SYN_SENT src=192.168.2.170 dst=72.14.205.83 sport=52242 dport=80 packets=1 bytes=64 [UNREPLIED] src=72.14.205.83 dst=24.136.2.99 sport=80 dport=52242 packets=0 bytes=0
[UPDATE] tcp 6 60 SYN_RECV src=192.168.2.170 dst=72.14.205.83 sport=52242 dport=80 packets=1 bytes=64 src=72.14.205.83 dst=24.136.2.99 sport=80 dport=52242 packets=1 bytes=60
[UPDATE] tcp 6 432000 ESTABLISHED src=192.168.2.170 dst=72.14.205.83 sport=52242 dport=80 packets=2 bytes=116 src=72.14.205.83 dst=24.136.2.99 sport=80 dport=52242 packets=1 bytes=60 [ASSURED]
[NEW] udp 17 30 src=192.168.100.25 dst=216.106.191.180 sport=123 dport=123 packets=1 bytes=76 [UNREPLIED] src=216.106.191.180 dst=24.136.2.99 sport=123 dport=123 packets=0 bytes=0
[UPDATE] udp 17 30 src=192.168.100.25 dst=216.106.191.180 sport=123 dport=123 packets=1 bytes=76 src=216.106.191.180 dst=24.136.2.99 sport=123 dport=123 packets=1 bytes=76
# conntrack -L | wc -l
41