LLDPD(8) BSD System Manager's Manual LLDPD(8)NAMElldpd — LLDP daemon
SYNOPSISlldpd [-dxcseiklrv] [-D debug] [-S description] [-P platform] [-X socket]
[-m management] [-u file] [-I interfaces] [-C interfaces]
[-M class] [-H hide] [-L lldpcli]
DESCRIPTIONlldpd 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
network.
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):
master agentx
This daemon implements both reception and sending. It will collect vari‐
ous 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. When specified one more time, will log to stderr
instead of using syslog. Then, this option can be specified many
times to increase verbosity. When specified four times, debug
logs will be enabled. They can be filtered with -D flag.
-D debug
This option allows the user to filter out debugging information
by specifying allowed tokens. This option can be repeated several
times to allow several tokens. This option must be combined with
the -d flag to have some effect. Only debugging logs can be fil‐
tered. Here is a list of allowed tokens with their description:
main Main daemon.
interfaces Discovery of local interfaces.
lldp LLDP PDU encoding/decoding.
edp EDP PDU encoding/decoding.
cdp CDP/FDP PDU encoding/decoding.
sonmp SONMP PDU encoding/decoding.
event Events management.
libevent Events management but for logs generated by
libevent.
privsep Privilege separation.
localchassis
Retrieval of information related to the local
chassis.
rpc Client communication.
control Management of the Unix control socket.
snmp SNMP subagent.
libsnmp SNMP subagent but for logs generated by NetSNMP.
decode Generic PDU decoding.
marshal Low-level serialization mechanisms.
alloc Low-level allocation mechanisms.
send Sending PDU to some interface.
receive Receiving PDU from some interface.
loop Main loop.
smartfilter
Smart filtering of different protocols on the
same port.
netlink Netlink subsystem.
-k Disable advertising of kernel release, version and machine. Ker‐
nel name (ie: Linux) will still be shared, and Inventory software
version will be set to 'Unknown'.
-S description
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).
-P platform
Override the CDP platform name with the provided value. The
default description is the kernel name (Linux).
-x Enable SNMP subagent. With this option, lldpd will enable an
SNMP subagent using AgentX protocol. This allows you to get
information about local system and remote systems through SNMP.
-X socket
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. If repeated once again,
CDPv2 packets will be sent even when there is no CDP peer
detected. If repeated once again (i.e. -cccc), CDPv1 will be
disabled and CDPv2 will be enabled. If repeated once again (i.e.
-ccccc), CDPv1 will be disabled and CDPv2 will be forced.
-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. If repeated, LLDP
is disabled.
-r Receive-only mode. With this switch, lldpd will not send any
frame. It will only listen to neighbors.
-m management
Specify the management addresses of this system. As for inter‐
faces (described below), this option can use wildcards and inver‐
sions. Without this option, the first IPv4 and the first IPv6
are used. If an exact IP address is provided, it is used as a
management address without any check. If only negative patterns
are provided, only one IPv4 and one IPv6 addresses are chosen.
Otherwise, many of them can be selected. If you want to blacklist
IPv6 addresses, you can use !*:*.
-u file
Specify the Unix-domain socket used for communication with
lldpctl(8).
-I interfaces
Specify which interface to listen and send LLDPDU to. Without
this option, lldpd will use all available physical interfaces.
This option can use wildcards. Several interfaces can be speci‐
fied separated by commas. It is also possible to blacklist an
interface by suffixing it with an exclamation mark. It is possi‐
ble to whitelist an interface by suffixing it with two exclama‐
tion marks. A whitelisted interface beats a blacklisted interface
which beats a simple matched interface. For example, with
eth*,!eth1,!eth2 lldpd will only use interfaces starting by eth
with the exception of eth1 and eth2. While with *,!eth*,!!eth1
lldpd will use all interfaces, except interfaces starting by eth
with the exception of eth1. When an exact match is found, it
will circumvent some tests. For example, if eth0.12 is specified,
it will be accepted even if this is a VLAN interface.
-C interfaces
Specify which interfaces to use for computing chassis ID. Without
this option, all interfaces are considered. lldpd will take the
first MAC address from all the considered interfaces to compute
the chassis ID. The logic of this option is the same as for -I
flag: you can exclude interfaces with an exclamation mark and use
globbing to specify several interfaces. If all interfaces are
blacklisted (with !*), the system name is used as a chassis ID
instead.
-M class
Enable emission of LLDP-MED frame. The class should be one of the
following value:
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.
-H hide
Filter neighbors. See section FILTERING NEIGHBORS for details.
-L lldpcli
Provide an alternative path to lldpcli for configuration. If
empty, does not use lldpcli for configuration.
-v Show lldpd version.
FILTERING NEIGHBORS
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.
Incoming filtering and outgoing filtering are unrelated. Incoming filter‐
ing will hide some remote ports to get you a chance to know exactly what
equipment is on the other side of the network cable. Outgoing filtering
will avoid to use some protocols to avoid flooding your network with a
protocol that is not handled by the nearest equipment. Keep in mind that
even without filtering, lldpd will speak protocols for which at least one
frame has been received and LLDP otherwise (there are other options to
change this behaviour, for example -cc, -ss, -ee, -ll and -ff ).
When enabling incoming filtering, lldpd will try to select one protocol
and filter out neighbors using other protocols. To select this protocol,
the rule is to take the less used protocol. If on one port, you get 12
CDP neighbors and 1 LLDP neighbor, this mean that the remote switch
speaks LLDP and does not filter CDP. Therefore, we select LLDP. When
enabling outgoing filtering, lldpd will also try to select one protocol
and only speaks this protocol. The filtering is done per port. Each port
may select a different protocol.
There are two additional criteria when enabling filtering: allowing one
or several protocols to be selected (in case of a tie) and allowing one
or several neighbors to be selected. Even when allowing several proto‐
cols, the rule of selecting the protocols with the less neighbors still
apply. If lldpd selects LLDP and CDP, this means they have the same num‐
ber of neighbors. The selection of the neighbor is random. Incoming fil‐
tering will select a set of neighbors to be displayed while outgoing fil‐
tering will use the selected set of neighbors to decide which protocols
to use: if a selected neighbor speaks LLDP and another one CDP, lldpd
will speak both CDP and LLDP on this port.
There are some corner cases. A typical example is a switch speaking two
protocols (CDP and LLDP for example). You want to get the information
from the best protocol but you want to speak both protocols because some
tools use the CDP table and some other the LLDP table.
The table below summarize all accepted values for the -H hide parameter.
The default value is 15 which corresponds to the corner case described
above. The filter column means that filtering is enabled. The 1proto col‐
umn tells that only one protocol will be kept. The 1neigh column tells
that only one neighbor will be kept.
incoming outgoing
filter 1proto 1neigh filter 1proto 1neigh
0
1 x x x x
2 x x
3 x x
4 x x
5 x
6 x
7 x x x x x
8 x x x
9 x x x x
10 x x
11 x x
12 x x x x
13 x x x
14 x x x x
15 x x x
16 x x x x x
17 x x x x
18 x x x
19 x x x
FILES
/var/run/lldpd.socket Unix-domain socket used for communication with
lldpctl(8).
/etc/lldpd.conf Configuration file for lldpd. Commands in this
files are executed by lldpcli(8) at start.
/etc/lldpd.d Directory containing configuration files whose
commands are executed by lldpcli(8) at start.
SEE ALSOlldpctl(8), lldpcli(8), snmpd(8)HISTORY
The lldpd program is inspired from a preliminary work of Reyk Floeter.
AUTHORS
The lldpd program was written by Pierre-Yves Ritschard ⟨pyr@openbsd.org⟩,
and Vincent Bernat ⟨bernat@luffy.cx⟩.
BSD April 28, 2024 BSD
