Link Layer Discovery Protocol

by Michael Tremer, May 28, 2011

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Today, I contributed a few lines of code to a project that is called lldpd and built by Vincent Bernat.

Technically known as IEEE 802.1AB, the Link Layer Discovery Protocol (LLDP) is – simply – used to figure out the network cabling. If you have a switch running LLDP it will receive LLDP packets that are sent from the host (which is in my case IPFire 3). In that packet, there is information about the IPFire system like management IP address and kernel version (won’t talk about the security issue here) and the switch adds the name of the port, the IPFire system is plugged in.

So what is the result? If you have a bigger kind of network with servers who have the LLDP daemon installed and running, you may easily find out on what switch port it is connected. Makes life of the average administrator a bit easier.

My patch was about adding support for the /etc/os-release file, which was introduced with systemd and acknowledged to be included in all major distributions. lldpd recently used the lsb_release command to figure out the distribution it was running on.;a=commitdiff;h=ae87586a12eaf4e8329b88f6e0c629e7b14f27bc

Thanks to Vincent, who accepted this upstream quickly.