ifstat

Ifstat is a software tool that provides real-time bandwidth reports for network interface, similar to the functions of vmstat and iostat for other system counters. There are two options for monitoring interfaces: polling the kernel counters for local interfaces, and using SNMP to access remote hosts' interfaces. Ifstat collects these statistics from kernel internal counters, which is highly dependent on the operating system used.

Fortunately, ifstat supports a variety of operating systems, including Linux, FreeBSD, Solaris, IRIX, OpenBSD, NetBSD, Darwin, Digital Unix, Tru64, Aix, and HP-UX. Ifstat obtains performance data for each system by utilizing unique interface such as file (/proc/net/dev), ifmib(4), kstat (3K), SIOCGIFDATA ioctl, route(4) sysctl, kvm(3), legacy kmem, and DPLI streams interface.

In addition, if net-snmp or ucd-snmp library is available, ifstat can be used to monitor remote equipments such as hosts, routers or switches. A SNMP daemon on local host is also an option for SNMP monitoring capability.

Ifstat has functionalities such as a static application, and configuration is straightforward by passing --enable-library. This feature provides an alternative way to use ifstat.

The recent release has added Digital Unix (OSF/1) and Tru64 support, Aix support, HP-UX support with DLPI streams interface, and native Win32 support (or with Cygwin) with GetIfTable interface. Another improvement is the utilization of net-snmp-config to find out SNMP flags.

Overall, Ifstat is a highly useful software tool for network administrators to obtain interface performance data.