lldpd: implementation of IEEE 802.1ab (LLDP)
--------------------------------------------

  https://trac.luffy.cx/lldpd/

LLDP (Link Layer Discovery Protocol) is an industry standard protocol
designed to supplant proprietary Link-Layer protocols such as
Extreme's EDP (Extreme Discovery Protocol) and CDP (Cisco Discovery
Protocol). The goal of LLDP is to provide an inter-vendor compatible
mechanism to deliver Link-Layer notifications to adjacent network
devices.

lldpd implements both reception and sending. It also implements an
SNMP subagent for net-snmp to get local and remote LLDP
information. The LLDP MIB is partially implemented but the most useful
tables are here. lldpd also partially implements LLDP-MED.

lldpd supports bridge, vlan and bonding. bonding need to be done on
real physical devices, not on bridges, vlans, etc. However, vlans can
be mapped on the bonding device. You can bridge vlan but not add vlans
on bridges. More complex setups may give false results.

To compile lldpd, use the following:
 ./configure
 make
 sudo make install

If it complains about a missing agent/struct.h, your installation of
Net-SNMP is incomplete. The easiest way to fix this is to provide an
empty struct.h:
 touch src/struct.h

lldpd uses privilege separation to increase its security. Two
processes, one running as root and doing minimal stuff and the other
running as an unprivileged user into a chroot doing most of the stuff,
are cooperating. You need to create a user called "_lldpd" in a group
"_lldpd" (this can be change with ./configure). You also need to
create an empty directory "/var/run/lldpd" (it needs to be owned by
root, not "_lldpd"!).

lldpctl allows to query information collected through the command
line. If you don't want to run it as root, just install it setuid or
setgid _lldpd.

lldpd also implements CDP (Cisco Discovery Protocol), FDP (Foundry
Discovery Protocol), SONMP (Nortel Discovery Protocol) and EDP
(Extreme Discovery Protocol). However, recent versions of IOS should
support LLDP and most Extreme stuff support LLDP. When a EDP, CDP or
SONMP frame is received on a given interface, lldpd starts sending
EDP, CDP, FDP or SONMP frame on this interface. Informations collected
through EDP/CDP/FDP/SONMP are integrated with other informations and
can be queried with lldpctl or through SNMP.

For bonding, you need 2.6.24 (in previous version, PACKET_ORIGDEV
affected only non multicast packets). See:
 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=80feaacb8a6400a9540a961b6743c69a5896b937
 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=8032b46489e50ef8f3992159abd0349b5b8e476c

Otherwise, real device will be choosen randomly.

On 2.6.27, we are able to receive packets on real interface for bonded
devices. This allows to get neighbor information on active/backup
bonds. Without the 2.6.27, lldpd won't receive any information on
inactive slaves. Here are the patchs (thanks to Joe Eykholt):
 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0d7a3681232f545c6a59f77e60f7667673ef0e93
 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cc9bd5cebc0825e0fabc0186ab85806a0891104f
 http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f982307f22db96201e41540295f24e8dcc10c78f

More information:
 http://en.wikipedia.org/wiki/LLDP
 http://standards.ieee.org/getieee802/download/802.1AB-2005.pdf
 http://wiki.wireshark.org/LinkLayerDiscoveryProtocol

lldpd is distributed under the following license:
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

OpenLLDP is another implementation of LLDP. It supports several OS
(Windows, Mac OS X, *BSD) and LLDP-MED extensions but does not include
an SNMP subagent or the support for CDP/SONMP.
 http://openlldp.sourceforge.net/