README.md

   1 lldpd: implementation of IEEE 802.1ab (LLDP)
   2 ============================================
   3
   4   https://github.com/vincentbernat/lldpd/wiki
   5
   6 LLDP (Link Layer Discovery Protocol) is an industry standard protocol
   7 designed to supplant proprietary Link-Layer protocols such as
   8 Extreme's EDP (Extreme Discovery Protocol) and CDP (Cisco Discovery
   9 Protocol). The goal of LLDP is to provide an inter-vendor compatible
  10 mechanism to deliver Link-Layer notifications to adjacent network
  11 devices.
  12
  13 lldpd implements both reception and sending. It also implements an
  14 SNMP subagent for net-snmp to get local and remote LLDP
  15 information. The LLDP MIB is partially implemented but the most useful
  16 tables are here. lldpd also partially implements LLDP-MED.
  17
  18 lldpd supports bridge, vlan and bonding. bonding need to be done on
  19 real physical devices, not on bridges, vlans, etc. However, vlans can
  20 be mapped on the bonding device. You can bridge vlan but not add vlans
  21 on bridges. More complex setups may give false results.
  22
  23 To compile lldpd, use the following:
  24
  25     ./configure
  26     make
  27     sudo make install
  28
  29 If it complains about a missing agent/struct.h, your installation of
  30 Net-SNMP is incomplete. The easiest way to fix this is to provide an
  31 empty struct.h:
  32
  33     touch src/struct.h
  34
  35 If you are missing some headers or if some headers are incorrect
  36 (if_vlan.h and if_bonding.h on RHEL 2.1 for example), you can copy
  37 some more current version (for example from Debian Lenny or from
  38 Fedora) in some directory like "extra-headers/":
  39
  40  - `./extra-headers/linux/if_vlan.h`
  41  - `./extra-headers/linux/if_bonding.h`
  42
  43 Then, configure like this:
  44
  45     ./configure CFLAGS="-Wall -I${PWD}/extra-headers"
  46
  47 This has been tested with RHEL 2.1.
  48
  49 lldpd uses privilege separation to increase its security. Two
  50 processes, one running as root and doing minimal stuff and the other
  51 running as an unprivileged user into a chroot doing most of the stuff,
  52 are cooperating. You need to create a user called `_lldpd` in a group
  53 `_lldpd` (this can be change with `./configure`). You also need to
  54 create an empty directory `/var/run/lldpd` (it needs to be owned by
  55 root, not `_lldpd`!). If you get fuzzy timestamps from syslog, copy
  56 `/etc/locatime` into the chroot.
  57
  58 `lldpctl` allows to query information collected through the command
  59 line. If you don't want to run it as root, just install it setuid or
  60 setgid `_lldpd`.
  61
  62 lldpd also implements CDP (Cisco Discovery Protocol), FDP (Foundry
  63 Discovery Protocol), SONMP (Nortel Discovery Protocol) and EDP
  64 (Extreme Discovery Protocol). However, recent versions of IOS should
  65 support LLDP and most Extreme stuff support LLDP. When a EDP, CDP or
  66 SONMP frame is received on a given interface, lldpd starts sending
  67 EDP, CDP, FDP or SONMP frame on this interface. Informations collected
  68 through EDP/CDP/FDP/SONMP are integrated with other informations and
  69 can be queried with `lldpctl` or through SNMP.
  70
  71 For bonding, you need 2.6.24 (in previous version, PACKET_ORIGDEV
  72 affected only non multicast packets). See:
  73
  74  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=80feaacb8a6400a9540a961b6743c69a5896b937
  75  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=8032b46489e50ef8f3992159abd0349b5b8e476c
  76
  77 Otherwise, a packet received on a bond will be affected to all
  78 interfaces of the bond.
  79
  80 On 2.6.27, we are able to receive packets on real interface for bonded
  81 devices. This allows to get neighbor information on active/backup
  82 bonds. Without the 2.6.27, lldpd won't receive any information on
  83 inactive slaves. Here are the patchs (thanks to Joe Eykholt):
  84
  85  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0d7a3681232f545c6a59f77e60f7667673ef0e93
  86  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cc9bd5cebc0825e0fabc0186ab85806a0891104f
  87  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f982307f22db96201e41540295f24e8dcc10c78f
  88
  89 Some devices (notably Cisco IOS) send frames on the native VLAN while
  90 they should send them untagged. If your network card does not support
  91 accelerated VLAN, you will receive those frames as well. However, if
  92 your network card handles VLAN encapsulation/decapsulation, you need a
  93 recent kernel to be able to receive those frames without listening on
  94 all available VLAN. Starting from Linux 2.6.27, lldpd is able to
  95 capture VLAN frames when VLAN acceleration is supported by the network
  96 card. Here is the patch:
  97  http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bc1d0411b804ad190cdadabac48a10067f17b9e6
  98
  99 More information:
 100  * http://en.wikipedia.org/wiki/LLDP
 101  * http://standards.ieee.org/getieee802/download/802.1AB-2005.pdf
 102  * http://wiki.wireshark.org/LinkLayerDiscoveryProtocol
 103
 104 lldpd is distributed under the following license:
 105
 106  > Permission to use, copy, modify, and distribute this software for any
 107  > purpose with or without fee is hereby granted, provided that the above
 108  > copyright notice and this permission notice appear in all copies.
 109  >
 110  > THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 111  > WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 112  > MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 113  > ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 114  > WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 115  > ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 116  > OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.