Network-I is a free network analyser suite, released under the
Grey Binary Licence,
that runs under Unix and does not require any specialised hardware.
It comprises a fast packet sniffer (Niftap) and a suite of additional tools (primarily Nifpan) that collectively perform the following main functions:
Network-I employs a powerful filtering language that allows you to zero in on
relevant services and interesting packets, and employs kernel-level filtering, for optimum performance.
- Capture and display network packets, in a configurable level of detail.
This is obviously useful for admins trouble-shooting network problems, but
is also of use to developers who need to test or debug their programs.
Unlike many other network monitors, Network-I will for instance display HTTP
messages in full.
- Record the peak rates of network traffic over extended periods of time,
in packets/second and bytes/second.
This helps to detect if routers or network segments are operating near
their capacity, and also provides a useful yardstick with which to measure
changes in traffic patterns, over time.
- Analyse traffic logs, and report on retransmissions and lost and corrupted packets.
- Display real-time graphs of bandwidth usage, by selected traffic (including
traffic levels at remote nodes).
The packet analyser can interpret a wide range of TCP/IP protocols
(ie. IP and TCP themselves, plus ICMP, DNS, RIP, BOOTP, DHCP, RADIUS, SNMP, NFS, LDAP, OSPF, etc),
as well as a wide variety of underlying link protocols (such as Ethernet, FDDI,