lldpd - LLDP daemon
lldpd [-dxcseikl] [-S description] [-X socket] [-m management] [-M class]
lldpd is a daemon able to receive and send LLDP frames. The Link Layer
Discovery Protocol is a vendor-neutral Layer 2 protocol that allows a
network device to advertise its identity and capabilities on the local
lldpd also implements an SNMP subagent using AgentX protocol to interface
to a regular SNMP agent like Net-SNMP. To enable this subagent, you need
something like that in your snmpd.conf(5):
This daemon implements both reception and sending. It will collect
various information to send LLDP frames to all Ethernet interfaces,
including management address, speed and VLAN names.
The options are as follows:
-d Do not daemonize. If this option is specified, lldpd will run in
the foreground and log to stderr. This option can be specified
many times to increase verbosity.
-k Disable advertising of kernel release, version and machine.
Kernel name (ie: Linux) will still be shared, and Inventory
software version will be set to ’Unknown’.
Override system description with the provided description. The
default description is the kernel name, the node name, the kernel
version, the build date and the architecture (except if you use
the -k flag described above).
-x Enable SNMP subagent. With this option, lldpd will enable an
SNMP subagent using AgentX protocol. This allows to get
information about local system and remote systems through SNMP.
Enable SNMP subagent using the specified socket. lldpd will
enable an SNMP subagent using AgentX protocol for the given
socket. This option implies the previous one. The default socket
is usally /var/agentx/master. You can specify a socket like
tcp:127.0.0.1:705 for example. Since the process that will open
this socket is enclosed in a chroot, you need to specify an IP
address (not a hostname) when using a TCP or UDP socket.
-c Enable the support of CDP protocol to deal with Cisco routers
that do not speak LLDP. If repeated, CDPv1 packets will be sent
even when there is no CDP peer detected.
-f Enable the support of FDP protocol to deal with Foundry routers
that do not speak LLDP. If repeated, FDP packets will be sent
even when there is no FDP peer detected.
-s Enable the support of SONMP protocol to deal with Nortel routers
and switches that do not speak LLDP. If repeated, SONMP packets
will be sent even when there is no SONMP peer detected.
-e Enable the support of EDP protocol to deal with Extreme routers
and switches that do not speak LLDP. If repeated, EDP packets
will be sent even when there is no EDP peer detected.
-l Force to send LLDP packets even when there is no LLDP peer
detected but there is a peer speaking another protocol detected.
By default, LLDP packets are sent when there is a peer speaking
LLDP detected or when there is no peer at all.
Specify the management address of this system. lldpd only sends
one management address. It will use the first one that it finds
or the one that you specify with this option. This option can use
Enable emission of LLDP-MED frame. The class should be one of the
1 Generic Endpoint (Class I)
2 Media Endpoint (Class II)
3 Communication Device Endpoints (Class III)
4 Network Connectivity Device
-i Disable LLDP-MED inventory TLV transmission. lldpd will still
receive (and publish using SNMP if enabled) those LLDP-MED TLV
but will not send them. Use this option if you don’t want to
transmit sensible information like serial numbers.
In a heterogeneous network, you may see several different hosts
on the same port, even if there is only one physically plugged to
this port. For example, if you have a Nortel switch running LLDP
which is plugged to a Cisco switch running CDP and your host is
plugged to the Cisco switch, you will see the Nortel switch as
well because LLDP frames are forwarded by the Cisco switch. This
may not be what you want. The -H hide parameter will allow you to
tell lldpd to discard some frames that it receives and to avoid
to send some other frames. The rationale behind the possible
modes is that we should guess which protocol the equipment we are
linked with is speaking. Moreover, it can speak several
protocols. The main idea used is that if we receive on one port
one CDP frame and three LLDP frames, we assume that the equipment
is speaking CDP and that LLDP frames are just flooded through
this equipment. The possible values are:
0 Do not be smart, do not filter any frame
1 For each port, get the protocol with less neighbors and use
only this protocol for reception and sending; in case of a
tie, LLDP protocol wins. This is the default mode.
2 For each port, get the protocol with less neighbors and use
only this protocol for reception; in case of a tie, LLDP
protocol wins. No frame is filtered when sending.
3 For each port, get the protocol with less neighbors and use
only this protocol for sending; in case of a tie, LLDP
protocol wins. No frame is filtered on reception.
4 Same as 1 but in case of a tie, both protocols win.
5 Same as 2 but in case of a tie, both protocols win.
6 Same as 3 but in case of a tie, both protocols win.
7 Same as 1 but only one neighbor is kept.
8 Same as 2 but only one neighbor is kept.
9 Same as 3 but only one neighbor is kept.
/var/run/lldpd.socket Unix-domain socket used for communication with
The lldpd program is inspired from a preliminary work of Reyk Floeter.
The lldpd program was written by Pierre-Yves Ritschard 〈firstname.lastname@example.org〉,
and Vincent Bernat 〈email@example.com〉.