README.md

   1 lldpd: implementation of IEEE 802.1ab (LLDP)
   2 ============================================
   3
   4 [![Build Status](https://secure.travis-ci.org/vincentbernat/lldpd.png?branch=master)](http://travis-ci.org/vincentbernat/lldpd)
   5
   6   http://vincentbernat.github.com/lldpd/
   7
   8 Features
   9 --------
  10
  11 LLDP (Link Layer Discovery Protocol) is an industry standard protocol
  12 designed to supplant proprietary Link-Layer protocols such as
  13 Extreme's EDP (Extreme Discovery Protocol) and CDP (Cisco Discovery
  14 Protocol). The goal of LLDP is to provide an inter-vendor compatible
  15 mechanism to deliver Link-Layer notifications to adjacent network
  16 devices.
  17
  18 lldpd implements both reception and sending. It also implements an
  19 SNMP subagent for net-snmp to get local and remote LLDP
  20 information. The LLDP-MIB is partially implemented but the most useful
  21 tables are here. lldpd also partially implements LLDP-MED.
  22
  23 lldpd supports bridge, vlan and bonding.
  24
  25 The following OS are supported:
  26
  27  * FreeBSD
  28  * GNU/Linux
  29  * Mac OS X
  30  * NetBSD
  31  * OpenBSD
  32  * Solaris
  33
  34 Installation
  35 ------------
  36
  37 For general instructions
  38 [see the website](http://vincentbernat.github.io/lldpd/installation.html).
  39
  40 To compile lldpd from sources, use the following:
  41
  42     ./configure
  43     make
  44     sudo make install
  45
  46 lldpd uses privilege separation to increase its security. Two
  47 processes, one running as root and doing minimal stuff and the other
  48 running as an unprivileged user into a chroot doing most of the stuff,
  49 are cooperating. You need to create a user called `_lldpd` in a group
  50 `_lldpd` (this can be change with `./configure`). You also need to
  51 create an empty directory `/usr/local/var/run/lldpd` (it needs to be
  52 owned by root, not `_lldpd`!). If you get fuzzy timestamps from
  53 syslog, copy `/etc/locatime` into the chroot.
  54
  55 `lldpcli` lets one query information collected through the command
  56 line. If you don't want to run it as root, just install it setuid or
  57 setgid `_lldpd`.
  58
  59 Installation (Mac OS X)
  60 -----------------------
  61
  62 The same procedure as above applies for Mac OS X. However, there are
  63 simpler alternatives:
  64
  65  1. Use [Homebrew](http://mxcl.github.io/homebrew/):
  66
  67         brew install lldpd
  68         # Or, for the latest version:
  69         brew install https://raw.github.com/vincentbernat/lldpd/master/osx/lldpd.rb
  70
  71  2. Build an OSX installer package which should work on the same
  72     version of OS X (it is important to use a separate build
  73     directory):
  74
  75         mkdir build && cd build
  76         ../configure --prefix=/usr --localstatedir=/var --sysconfdir=/private/etc --with-embedded-libevent
  77         make -C osx pkg ARCHS="i386 x86_64"
  78
  79     If you want to compile for an older version of Mac OS X, you need
  80     to find the right SDK and issues commands like those:
  81
  82         SDK=/Developer/SDKs/MacOSX10.6.sdk
  83         mkdir build && cd build
  84         ../configure --prefix=/usr --localstatedir=/var --sysconfdir=/private/etc --with-embedded-libevent \
  85            CFLAGS="-mmacosx-version-min=10.6 -isysroot $SDK" \
  86            LDFLAGS="-mmacosx-version-min=10.6 -isysroot $SDK"
  87         make -C osx pkg ARCHS="i386 x86_64"
  88
  89 If you don't follow the above procedures, you will have to create the
  90 user/group `_lldpd`. Have a look at how this is done in
  91 `osx/scripts/postinstall`.
  92
  93 Installation (Android)
  94 ----------------------
  95
  96 You need to download [Android NDK][]. Once unpacked, you can generate
  97 a toolchain using the following command:
  98
  99     ./build/tools/make-standalone-toolchain.sh \
 100         --platform=android-9 \
 101         --arch=arm \
 102         --install-dir=../android-toolchain
 103     export TOOLCHAIN=$PWD/../android-toolchain
 104
 105 Then, you can build `lldpd` with the following commands:
 106
 107     mkdir build && cd build
 108     export PATH=$PATH:$TOOLCHAIN/bin
 109     ../configure \
 110         --host=arm-linux-androideabi \
 111         --with-sysroot=$TOOLCHAIN/sysroot
 112
 113 [Android NDK]: http://developer.android.com/tools/sdk/ndk/index.html
 114
 115 Usage
 116 -----
 117
 118 lldpd also implements CDP (Cisco Discovery Protocol), FDP (Foundry
 119 Discovery Protocol), SONMP (Nortel Discovery Protocol) and EDP
 120 (Extreme Discovery Protocol). However, recent versions of IOS should
 121 support LLDP and most Extreme stuff support LLDP. When a EDP, CDP or
 122 SONMP frame is received on a given interface, lldpd starts sending
 123 EDP, CDP, FDP or SONMP frame on this interface. Informations collected
 124 through EDP/CDP/FDP/SONMP are integrated with other informations and
 125 can be queried with `lldpcli` or through SNMP.
 126
 127 For bonding, you need 2.6.24 (in previous version, PACKET_ORIGDEV
 128 affected only non multicast packets). See:
 129
 130  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=80feaacb8a6400a9540a961b6743c69a5896b937
 131  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=8032b46489e50ef8f3992159abd0349b5b8e476c
 132
 133 Otherwise, a packet received on a bond will be affected to all
 134 interfaces of the bond.
 135
 136 On 2.6.27, we are able to receive packets on real interface for bonded
 137 devices. This allows one to get neighbor information on active/backup
 138 bonds. Without the 2.6.27, lldpd won't receive any information on
 139 inactive slaves. Here are the patchs (thanks to Joe Eykholt):
 140
 141  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0d7a3681232f545c6a59f77e60f7667673ef0e93
 142  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cc9bd5cebc0825e0fabc0186ab85806a0891104f
 143  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f982307f22db96201e41540295f24e8dcc10c78f
 144
 145 On FreeBSD, only a recent 9 kernel (9.1 or more recent) will allow to
 146 send LLDP frames on enslaved devices. See this bug report for more
 147 information:
 148
 149  * http://www.freebsd.org/cgi/query-pr.cgi?pr=138620
 150
 151 Some devices (notably Cisco IOS) send frames on tagged with the native
 152 VLAN while they should send them untagged. If your network card does
 153 not support accelerated VLAN, you will receive those frames as long as
 154 the corresponding interface exists (see below). However, if your
 155 network card handles VLAN encapsulation/decapsulation (check with
 156 `ethtool -k`), you need a recent kernel to be able to receive those
 157 frames without listening on all available VLAN. Starting from Linux
 158 2.6.27, lldpd is able to capture VLAN frames when VLAN acceleration is
 159 supported by the network card. Here is the patch:
 160
 161  * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=bc1d0411b804ad190cdadabac48a10067f17b9e6
 162
 163 On some other versions, frames are sent on VLAN 1. If this is not the
 164 native VLAN and if your network card support accelerated VLAN, you
 165 need to subscribe to this VLAN as well. The Linux kernel does not
 166 provide any interface for this. The easiest way is to create the VLAN
 167 for each port:
 168
 169     ip link add link eth0 name eth0.1 type vlan id 1
 170     ip link set up dev eth0.1
 171
 172 You can check both cases using tcpdump:
 173
 174     tcpdump -epni eth0 ether host 01:80:c2:00:00:0e
 175     tcpdump -eni eth0 ether host 01:80:c2:00:00:0e
 176
 177 If the first command does not display received LLDP packets but the
 178 second one does, LLDP packets are likely encapsulated into a VLAN:
 179
 180     10:54:06.431154 f0:29:29:1d:7c:01 > 01:80:c2:00:00:0e, ethertype 802.1Q (0x8100), length 363: vlan 1, p 7, ethertype LLDP, LLDP, name SW-APP-D07.VTY, length 345
 181
 182 In this case, just create VLAN 1 will fix the situation. There are
 183 other solutions:
 184
 185  1. Disable VLAN acceleration on the receive side (`ethtool -K eth0
 186     rxvlan off`) but this may or may not work. Check if there are
 187     similar properties that could apply with `ethtool -k eth0`.
 188  2. Put the interface in promiscuous mode with `ip link set
 189     promisc on dev eth0`.
 190
 191 The last solution can be done directly by `lldpd` (on Linux only) by
 192 using the option `configure system interface promiscuous`.
 193
 194 On modern networks, the performance impact should be nonexistent.
 195
 196 More information:
 197  * http://en.wikipedia.org/wiki/Link_Layer_Discovery_Protocol
 198  * http://standards.ieee.org/getieee802/download/802.1AB-2005.pdf
 199  * http://wiki.wireshark.org/LinkLayerDiscoveryProtocol
 200
 201 Development
 202 -----------
 203
 204 During development, you may want to execute lldpd at its current
 205 location inside of doing `make install`. The correct way to do this is
 206 to issue the following command:
 207
 208     sudo libtool execute src/daemon/lldpd -L $PWD/src/client/lldpcli -d
 209
 210 You can append any further arguments. If lldpd is unable to find
 211 `lldpcli` it will start in an unconfigured mode and won't send or
 212 accept LLDP frames.
 213
 214 Embedding
 215 ---------
 216
 217 To embed lldpd into an existing system, there are two point of entries:
 218
 219  1. If your system does not use standard Linux interface, you can
 220     support additional interfaces by implementing the appropriate
 221     `struct lldpd_ops`. You can look at
 222     `src/daemon/interfaces-linux.c` for examples. Also, have a look at
 223     `interfaces_update()` which is responsible for discovering and
 224     registering interfaces.
 225
 226  2. `lldpcli` provides a convenient way to query `lldpd`. It also
 227     comes with various outputs, including XML which allows one to
 228     parse its output for integration and automation purpose. Another
 229     way is to use SNMP support. A third way is to write your own
 230     controller using `liblldpctl.so`. Its API is described in
 231     `src/lib/lldpctl.h`. The custom binary protocol between
 232     `liblldpctl.so` and `lldpd` is not stable. Therefore, the library
 233     should always be shipped with `lldpd`. On the other hand, programs
 234     using `liblldpctl.so` can rely on the classic ABI rules.
 235
 236 Troubleshooting
 237 ---------------
 238
 239 You can use `tcpdump` to look after the packets received and send by
 240 `lldpd`. To look after LLDPU, use:
 241
 242     tcpdump -s0 -vv -pni eth0 ether dst 01:80:c2:00:00:0e
 243
 244 License
 245 -------
 246
 247 lldpd is distributed under the ISC license:
 248
 249  > Permission to use, copy, modify, and/or distribute this software for any
 250  > purpose with or without fee is hereby granted, provided that the above
 251  > copyright notice and this permission notice appear in all copies.
 252  >
 253  > THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 254  > WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 255  > MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 256  > ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 257  > WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 258  > ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 259  > OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 260
 261 Also, `lldpcli` will be linked to GNU Readline (which is GPL licensed)
 262 if available. To avoid this, use `--without-readline` as a configure
 263 option.