Netstat-nat is a small program written in C. It displays NAT connections, managed by netfilter/iptables which comes with the > 2.4.x linux kernels. The program reads its information from '/proc/net/ip_conntrack', which is the temporary conntrack-storage of netfilter. (http://netfilter.samba.org/). Netstat-nat takes several arguments but they not needed.
-h displays help
-n don't resolve IPs/ports to host/portnames.
-p 'protocol' display NAT connections with protocol selection.
-s 'source host' display connections by source IP/hostname.
-d 'destination host' display connections by destination IP/hostname.
-S display SNAT connections
-D display DNAT connections
-L display only connections to NAT box self (disables display of SNAT & DNAT)
-x extended view of hostnames
-r src | dst | src-port | dst-port | state sort connections
-o strip output-header
What's New in This Release:
· nf_conntrack support was added.
· A feature to show NAT host information (port and IP address) was added.
· A feature to show only routed connections was added.
· Some memory allocation and releasing bugs were squashed.