1 Internet Systems Consortium DHCP Distribution 2 Version 4.3.0 3 3 February 2014 4 5 README FILE 6 7You should read this file carefully before trying to install or use 8the ISC DHCP Distribution. 9 10 TABLE OF CONTENTS 11 12 1 WHERE TO FIND DOCUMENTATION 13 2 RELEASE STATUS 14 3 BUILDING THE DHCP DISTRIBUTION 15 3.1 UNPACKING IT 16 3.2 CONFIGURING IT 17 3.2.1 DYNAMIC DNS UPDATES 18 3.2.2 LOCALLY DEFINED OPTIONS 19 3.3 BUILDING IT 20 4 INSTALLING THE DHCP DISTRIBUTION 21 5 USING THE DHCP DISTRIBUTION 22 5.1 FIREWALL RULES 23 5.2 LINUX 24 5.2.1 IF_TR.H NOT FOUND 25 5.2.2 SO_ATTACH_FILTER UNDECLARED 26 5.2.3 PROTOCOL NOT CONFIGURED 27 5.2.4 BROADCAST 28 5.2.6 IP BOOTP AGENT 29 5.2.7 MULTIPLE INTERFACES 30 5.3 SCO 31 5.4 HP-UX 32 5.5 ULTRIX 33 5.6 FreeBSD 34 5.7 NeXTSTEP 35 5.8 SOLARIS 36 5.8.1 Solaris 11 37 5.8.2 Solaris 11 and ATF 38 5.8.3 Other Solaris Items 39 5.9 AIX 40 5.10 MacOS X 41 6 SUPPORT 42 6.1 HOW TO REPORT BUGS 43 7 HISTORY 44 45 WHERE TO FIND DOCUMENTATION 46 47Documentation for this software includes this README file, the 48RELNOTES file, and the manual pages, which are in the server, common, 49client and relay subdirectories. The README file (this file) includes 50late-breaking operational and system-specific information that you 51should read even if you don't want to read the manual pages, and that 52you should *certainly* read if you run into trouble. Internet 53standards relating to the DHCP protocol are listed in the References 54document that is available in html, txt and xml formats in doc/ 55subdirectory. You will have the best luck reading the manual pages if 56you build this software and then install it, although you can read 57them directly out of the distribution if you need to. 58 59DHCP server documentation is in the dhcpd man page. Information about 60the DHCP server lease database is in the dhcpd.leases man page. 61Server configuration documentation is in the dhcpd.conf man page as 62well as the dhcp-options man page. A sample DHCP server 63configuration is in the file server/dhcpd.conf.example. The source for 64the dhcpd, dhcpd.leases and dhcpd.conf man pages is in the server/ sub- 65directory in the distribution. The source for the dhcp-options.5 66man page is in the common/ subdirectory. 67 68DHCP Client documentation is in the dhclient man page. DHCP client 69configuration documentation is in the dhclient.conf man page and the 70dhcp-options man page. The DHCP client configuration script is 71documented in the dhclient-script man page. The format of the DHCP 72client lease database is documented in the dhclient.leases man page. 73The source for all these man pages is in the client/ subdirectory in 74the distribution. In addition, the dhcp-options man page should be 75referred to for information about DHCP options. 76 77DHCP relay agent documentation is in the dhcrelay man page, the source 78for which is distributed in the relay/ subdirectory. 79 80To read installed manual pages, use the man command. Type "man page" 81where page is the name of the manual page. This will only work if 82you have installed the ISC DHCP distribution using the ``make install'' 83command (described later). 84 85If you want to read manual pages that aren't installed, you can type 86``nroff -man page |more'' where page is the filename of the 87unformatted manual page. The filename of an unformatted manual page 88is the name of the manual page, followed by '.', followed by some 89number - 5 for documentation about files, and 8 for documentation 90about programs. For example, to read the dhcp-options man page, 91you would type ``nroff -man common/dhcp-options.5 |more'', assuming 92your current working directory is the top level directory of the ISC 93DHCP Distribution. 94 95Please note that the pathnames of files to which our manpages refer 96will not be correct for your operating system until after you iterate 97'make install' (so if you're reading a manpage out of the source 98directory, it may not have up-to-date information). 99 100 RELEASE STATUS 101 102This is ISC DHCP 4.3.0. The major theme for this release is "ipv6 uplift", 103in which we enhance the v6 code to support many of the features found 104in the v4 code. These include: support for v6, support for on_commit, 105on_expiry and on_release in v6, support for accessing v6 relay options 106and better log messages for v6 addresses. Non v6 features include: 107support for the standard DDNS, better OMAPI class and sub-class support 108allowing for dynamic addition and removal of sub-classes, and support for 109DDNS without zone statements. 110 111In this release, the DHCPv6 server should be fully functional on Linux, 112Solaris, or any BSD. The DHCPv6 client should be similarly functional 113except on Solaris. 114 115The DHCPv4 server, relay, and client, should be fully functional 116on Linux, Solaris, any BSD, HPUX, SCO, NextSTEP, and Irix. 117 118If you are running the DHCP distribution on a machine which is a 119firewall, or if there is a firewall between your DHCP server(s) and 120DHCP clients, please read the section on firewalls which appears later 121in this document. 122 123If you wish to run the DHCP Distribution on Linux, please see the 124Linux-specific notes later in this document. If you wish to run on an 125SCO release, please see the SCO-specific notes later in this document. 126You particularly need to read these notes if you intend to support 127Windows 95 clients. If you are running HP-UX or Ultrix, please read the 128notes for those operating systems below. If you are running NeXTSTEP, 129please see the notes on NeXTSTEP below. 130 131If you start dhcpd and get a message, "no free bpf", that means you 132need to configure the Berkeley Packet Filter into your operating 133system kernel. On NetBSD, FreeBSD and BSD/os, type ``man bpf'' for 134information. On Digital Unix, type ``man pfilt''. 135 136 137 BUILDING THE DHCP DISTRIBUTION 138 139 UNPACKING IT 140 141To build the DHCP Distribution, unpack the compressed tar file using 142the tar utility and the gzip command - type something like: 143 144 gunzip dhcp-4.3.0.tar.gz 145 tar xvf dhcp-4.3.0.tar 146 147 CONFIGURING IT 148 149Now, cd to the dhcp-4.3.0 subdirectory that you've just created and 150configure the source tree by typing: 151 152 ./configure 153 154If the configure utility can figure out what sort of system you're 155running on, it will create a custom Makefile for you for that 156system; otherwise, it will complain. If it can't figure out what 157system you are using, that system is not supported - you are on 158your own. 159 160Several options may be enabled or disabled via the configure command. 161You can get a list of these by typing: 162 163 ./configure --help 164 165 DYNAMIC DNS UPDATES 166 167A fully-featured implementation of dynamic DNS updates is included in 168this release. It uses libraries from BIND and, to avoid issues with 169different versions, includes the necessary BIND version. The appropriate 170BIND libraries will be compiled and installed in the bind subdirectory 171as part of the make step. In order to build the necessary libraries you 172will need to have "gmake" available on your build system. 173 174 175There is documentation for the DDNS support in the dhcpd.conf manual 176page - see the beginning of this document for information on finding 177manual pages. 178 179 LOCALLY DEFINED OPTIONS 180 181In previous versions of the DHCP server there was a mechanism whereby 182options that were not known by the server could be configured using 183a name made up of the option code number and an identifier: 184"option-nnn" This is no longer supported, because it is not future- 185proof. Instead, if you want to use an option that the server doesn't 186know about, you must explicitly define it using the method described 187in the dhcp-options man page under the DEFINING NEW OPTIONS heading. 188 189 BUILDING IT 190 191Once you've run configure, just type ``make'', and after a while 192you should have a dhcp server. If you get compile errors on one 193of the supported systems mentioned earlier, please let us know. 194If you get warnings, it's not likely to be a problem - the DHCP 195server compiles completely warning-free on as many architectures 196as we can manage, but there are a few for which this is difficult. 197If you get errors on a system not mentioned above, you will need 198to do some programming or debugging on your own to get the DHCP 199Distribution working. 200 201 INSTALLING THE DHCP DISTRIBUTION 202 203Once you have successfully gotten the DHCP Distribution to build, you 204can install it by typing ``make install''. If you already have an old 205version of the DHCP Distribution installed, you may want to save it 206before typing ``make install''. 207 208 USING THE DHCP DISTRIBUTION 209 210 FIREWALL RULES 211 212If you are running the DHCP server or client on a computer that's also 213acting as a firewall, you must be sure to allow DHCP packets through 214the firewall. In particular, your firewall rules _must_ allow packets 215from IP address 0.0.0.0 to IP address 255.255.255.255 from UDP port 68 216to UDP port 67 through. They must also allow packets from your local 217firewall's IP address and UDP port 67 through to any address your DHCP 218server might serve on UDP port 68. Finally, packets from relay agents 219on port 67 to the DHCP server on port 67, and vice versa, must be 220permitted. 221 222We have noticed that on some systems where we are using a packet 223filter, if you set up a firewall that blocks UDP port 67 and 68 224entirely, packets sent through the packet filter will not be blocked. 225However, unicast packets will be blocked. This can result in strange 226behaviour, particularly on DHCP clients, where the initial packet 227exchange is broadcast, but renewals are unicast - the client will 228appear to be unable to renew until it starts broadcasting its 229renewals, and then suddenly it'll work. The fix is to fix the 230firewall rules as described above. 231 232 PARTIAL SERVERS 233 234If you have a server that is connected to two networks, and you only 235want to provide DHCP service on one of those networks (e.g., you are 236using a cable modem and have set up a NAT router), if you don't write 237any subnet declaration for the network you aren't supporting, the DHCP 238server will ignore input on that network interface if it can. If it 239can't, it will refuse to run - some operating systems do not have the 240capability of supporting DHCP on machines with more than one 241interface, and ironically this is the case even if you don't want to 242provide DHCP service on one of those interfaces. 243 244 LINUX 245 246There are three big LINUX issues: the all-ones broadcast address, 247Linux 2.1 ip_bootp_agent enabling, and operations with more than one 248network interface. There are also two potential compilation/runtime 249problems for Linux 2.1/2.2: the "SO_ATTACH_FILTER undeclared" problem 250and the "protocol not configured" problem. 251 252 LINUX: PROTOCOL NOT CONFIGURED 253 254If you get the following message, it's because your kernel doesn't 255have the linux packetfilter or raw packet socket configured: 256 257 Make sure CONFIG_PACKET (Packet socket) and CONFIG_FILTER (Socket 258 Filtering) are enabled in your kernel configuration 259 260If this happens, you need to configure your Linux kernel to support 261Socket Filtering and the Packet socket, or to select a kernel provided 262by your Linux distribution that has these enabled (virtually all modern 263ones do by default). 264 265 LINUX: BROADCAST 266 267If you are running a recent version of Linux, this won't be a problem, 268but on older versions of Linux (kernel versions prior to 2.2), there 269is a potential problem with the broadcast address being sent 270incorrectly. 271 272In order for dhcpd to work correctly with picky DHCP clients (e.g., 273Windows 95), it must be able to send packets with an IP destination 274address of 255.255.255.255. Unfortunately, Linux changes an IP 275destination of 255.255.255.255 into the local subnet broadcast address 276(here, that's 192.5.5.223). 277 278This isn't generally a problem on Linux 2.2 and later kernels, since 279we completely bypass the Linux IP stack, but on old versions of Linux 2802.1 and all versions of Linux prior to 2.1, it is a problem - pickier 281DHCP clients connected to the same network as the ISC DHCP server or 282ISC relay agent will not see messages from the DHCP server. It *is* 283possible to run into trouble with this on Linux 2.2 and later if you 284are running a version of the DHCP server that was compiled on a Linux 2852.0 system, though. 286 287It is possible to work around this problem on some versions of Linux 288by creating a host route from your network interface address to 289255.255.255.255. The command you need to use to do this on Linux 290varies from version to version. The easiest version is: 291 292 route add -host 255.255.255.255 dev eth0 293 294On some older Linux systems, you will get an error if you try to do 295this. On those systems, try adding the following entry to your 296/etc/hosts file: 297 298255.255.255.255 all-ones 299 300Then, try: 301 302 route add -host all-ones dev eth0 303 304Another route that has worked for some users is: 305 306 route add -net 255.255.255.0 dev eth0 307 308If you are not using eth0 as your network interface, you should 309specify the network interface you *are* using in your route command. 310 311 LINUX: IP BOOTP AGENT 312 313Some versions of the Linux 2.1 kernel apparently prevent dhcpd from 314working unless you enable it by doing the following: 315 316 echo 1 >/proc/sys/net/ipv4/ip_bootp_agent 317 318 319 LINUX: MULTIPLE INTERFACES 320 321Very old versions of the Linux kernel do not provide a networking API 322that allows dhcpd to operate correctly if the system has more than one 323broadcast network interface. However, Linux 2.0 kernels with version 324numbers greater than or equal to 2.0.31 add an API feature: the 325SO_BINDTODEVICE socket option. If SO_BINDTODEVICE is present, it is 326possible for dhcpd to operate on Linux with more than one network 327interface. In order to take advantage of this, you must be running a 3282.0.31 or greater kernel, and you must have 2.0.31 or later system 329headers installed *before* you build the DHCP Distribution. 330 331We have heard reports that you must still add routes to 255.255.255.255 332in order for the all-ones broadcast to work, even on 2.0.31 kernels. 333In fact, you now need to add a route for each interface. Hopefully 334the Linux kernel gurus will get this straight eventually. 335 336Linux 2.1 and later kernels do not use SO_BINDTODEVICE or require the 337broadcast address hack, but do support multiple interfaces, using the 338Linux Packet Filter. 339 340 LINUX: OpenWrt 341 342DHCP 4.1 has been tested on OpenWrt 7.09 and 8.09. In keeping with 343standard practice, client/scripts now includes a dhclient-script file 344for OpenWrt. However, this is not sufficient by itself to run dhcp on 345OpenWrt; a full OpenWrt package for DHCP is available at 346ftp://ftp.isc.org/isc/dhcp/dhcp-4.1.0-openwrt.tar.gz 347 348 LINUX: 802.1q VLAN INTERFACES 349 350If you're using 802.1q vlan interfaces on Linux, it is necessary to 351vconfig the subinterface(s) to rewrite the 802.1q information out of 352packets received by the dhcpd daemon via LPF: 353 354 vconfig set_flag eth1.523 1 1 355 356Note that this may affect the performance of your system, since the 357Linux kernel must rewrite packets received via this interface. For 358more information, consult the vconfig man pages. 359 360 SCO 361 362ISC DHCP will now work correctly on newer versions of SCO out of the 363box (tested on OpenServer 5.05b, assumed to work on UnixWare 7). 364 365Older versions of SCO have the same problem as Linux (described earlier). 366The thing is, SCO *really* doesn't want to let you add a host route to 367the all-ones broadcast address. 368 369You can try the following: 370 371 ifconfig net0 xxx.xxx.xxx.xxx netmask 0xNNNNNNNN broadcast 255.255.255.255 372 373If this doesn't work, you can also try the following strange hack: 374 375 ifconfig net0 alias 10.1.1.1 netmask 8.0.0.0 376 377Apparently this works because of an interaction between SCO's support 378for network classes and the weird netmask. The 10.* network is just a 379dummy that can generally be assumed to be safe. Don't ask why this 380works. Just try it. If it works for you, great. 381 382 HP-UX 383 384HP-UX has the same problem with the all-ones broadcast address that 385SCO and Linux have. One user reported that adding the following to 386/etc/rc.config.d/netconf helped (you may have to modify this to suit 387your local configuration): 388 389INTERFACE_NAME[0]=lan0 390IP_ADDRESS[0]=1.1.1.1 391SUBNET_MASK[0]=255.255.255.0 392BROADCAST_ADDRESS[0]="255.255.255.255" 393LANCONFIG_ARGS[0]="ether" 394DHCP_ENABLE[0]=0 395 396 ULTRIX 397 398Now that we have Ultrix packet filter support, the DHCP Distribution 399on Ultrix should be pretty trouble-free. However, one thing you do 400need to be aware of is that it now requires that the pfilt device be 401configured into your kernel and present in /dev. If you type ``man 402packetfilter'', you will get some information on how to configure your 403kernel for the packet filter (if it isn't already) and how to make an 404entry for it in /dev. 405 406 FreeBSD 407 408Versions of FreeBSD prior to 2.2 have a bug in BPF support in that the 409ethernet driver swaps the ethertype field in the ethernet header 410downstream from BPF, which corrupts the output packet. If you are 411running a version of FreeBSD prior to 2.2, and you find that dhcpd 412can't communicate with its clients, you should #define BROKEN_FREEBSD_BPF 413in site.h and recompile. 414 415Modern versions of FreeBSD include the ISC DHCP 3.0 client as part of 416the base system, and the full distribution (for the DHCP server and 417relay agent) is available from the Ports Collection in 418/usr/ports/net/isc-dhcp3, or as a package on FreeBSD installation 419CDROMs. 420 421 NeXTSTEP 422 423The NeXTSTEP support uses the NeXTSTEP Berkeley Packet Filter 424extension, which is not included in the base NextStep system. You 425must install this extension in order to get dhcpd or dhclient to work. 426 427 SOLARIS 428 429There are two known issues seen when compiling using the Sun compiler. 430 431The first is that older Sun compilers generate an error on some of 432our uses of the flexible array option. Newer versions only generate 433a warning, which can be safely ignored. If you run into this error 434("type of struct member "buf" can not be derived from structure with 435flexible array member"), upgrade your tools to Oracle Solaris Studio 436(previously Sun Studio) 12 or something newer. 437 438The second is the interaction between the configure script and the 439makefiles for the Bind libraries. Currently we don't pass all 440environment variables between the DHCP configure and the Bind configure. 441 442If you attempt to specify the compiler you wish to use like this: 443 444 CC=/opt/SUNWspro/bin/cc ./configure 445 446"make" may not build the Bind libraries with that compiler. 447 448In order to use the same compiler for Bind and DHCP we suggest the 449following commands: 450 451 CC=/opt/SUNWspro/bin/cc ./configure 452 CC=/opt/SUNWspro/bin/cc make 453 454 Solaris 11 455 456We have integrated a patch from Oracle to use sockets instead of 457DLPI on Solaris 11. This functionality was written for use with 458Solaris Studio 12.2 and requires the system/header package. 459 460By default this code is disabled in order to minimize disruptions 461for current users. In order to enable this code you will need to 462enable both USE_SOCKETS and USE_V4_PKTINFO as part of the 463configuration step. The command line would be something like: 464 465 ./configure --enable-use-sockets --enable-ipv4-pktinfo 466 467 Solaris 11 and ATF 468 469We have reports that ATF 0.15 and 0.16 do not build on Solaris 11. The 470following changes to the ATF source code appear to fix this issue: 471 472diff -ru atf-0.15/atf-c/tp_test.c atf-0.15-patched/atf-c/tp_test.c 473--- atf-0.15/atf-c/tp_test.c 2011-12-06 06:31:11.000000000 +0100 474+++ atf-0.15-patched/atf-c/tp_test.c 2012-06-19 15:54:57.000000000 +0200 475@@ -28,6 +28,7 @@ 476*/ 477 478#include <string.h> 479+#include <stdio.h> 480#include <unistd.h> 481 482#include <atf-c.h> 483 484diff -ru atf-0.15/atf-run/requirements.cpp atf-0.15-patched/atf-run/requirements.cpp 485--- atf-0.15/atf-run/requirements.cpp 2012-01-13 20:44:25.000000000 +0100 486+++ atf-0.15-patched/atf-run/requirements.cpp 2012-06-19 15:41:51.000000000 +0200 487@@ -29,7 +29,7 @@ 488 489extern "C" { 490#include <sys/param.h> 491-#include <sys/sysctl.h> 492+//#include <sys/sysctl.h> 493} 494 495#include <cerrno> 496 497 Other Solaris Items 498 499One problem which has been observed and is not fixed in this 500patchlevel has to do with using DLPI on Solaris machines. The symptom 501of this problem is that the DHCP server never receives any requests. 502This has been observed with Solaris 2.6 and Solaris 7 on Intel x86 503systems, although it may occur with other systems as well. If you 504encounter this symptom, and you are running the DHCP server on a 505machine with a single broadcast network interface, you may wish to 506edit the includes/site.h file and uncomment the #define USE_SOCKETS 507line. Then type ``make clean; make''. As an alternative workaround, 508it has been reported that running 'snoop' will cause the dhcp server 509to start receiving packets. So the practice reported to us is to run 510snoop at dhcpd startup time, with arguments to cause it to receive one 511packet and exit. 512 513 snoop -c 1 udp port 67 > /dev/null & 514 515The DHCP client on Solaris will only work with DLPI. If you run it 516and it just keeps saying it's sending DHCPREQUEST packets, but never 517gets a response, you may be having DLPI trouble as described above. 518If so, we have no solution to offer at this time, aside from the above 519workaround which should also work here. Also, because Solaris requires 520you to "plumb" an interface before it can be detected by the DHCP client, 521you must either specify the name(s) of the interface(s) you want to 522configure on the command line, or must plumb the interfaces prior to 523invoking the DHCP client. This can be done with ``ifconfig iface plumb'', 524where iface is the name of the interface (e.g., ``ifconfig hme0 plumb''). 525 526It should be noted that Solaris versions from 2.6 onward include a 527DHCP client that you can run with ``/sbin/ifconfig iface dhcp start'' 528rather than using the ISC DHCP client, including DHCPv6. Consequently, 529we don't believe there is a need for the client to run on Solaris, and 530have not engineered the needed DHCPv6 modifications for the dhclient-script. 531If you feel this is in error, or have a need, please contact us. 532 533 AIX 534 535The AIX support uses the BSD socket API, which cannot differentiate on 536which network interface a broadcast packet was received; thus the DHCP 537server and relay will work only on a single interface. (They do work 538on multi-interface machines if configured to listen on only one of the 539interfaces.) 540 541We have reports of Windows XP clients having difficulty retrieving 542addresses from a server running on an AIX machine. This issue 543was traced to the client requiring messages be sent to the all ones 544broadcast address (255.255.255.255) while the AIX server was sending 545to 192.168.0.255. 546 547You may be able to solve this by including a relay between the client 548and server with the relay configured to use a broadcast of all-ones. 549 550A second option that worked for AIX 5.1 but doesn't seem to work for 551AIX 5.3 was to: 552 create a host file entry for all-ones (255.255.255.255) 553and then add a route: 554 route add -host all-ones -interface <local-ip-address> 555 556The ISC DHCP distribution does not include a dhclient-script for AIX-- 557AIX comes with a DHCP client. Contribution of a working dhclient-script 558for AIX would be welcome. 559 560 561 MacOS X 562 563The MacOS X system uses a TCP/IP stack derived from FreeBSD with a 564user-friendly interface named the System Configuration Framework. 565As it includes a builtin DHCPv4 client (you are better just using that), 566this text is only about the DHCPv6 client (``dhclient -6 ...''). The DNS 567configuration (domain search list and name servers' addresses) is managed 568by a System Configuration agent, not by /etc/resolv.conf (which is a link 569to /var/run/resolv.conf, which itself only reflects the internal state; 570the System Configuration framework's Dynamic Store). 571 572This means that modifying resolv.conf directly doesn't have the 573intended effect, instead the macos script sample creates its own 574resolv.conf.dhclient6 in /var/run, and inserts the contents of this 575file into the Dynamic Store. 576 577When updating the address configuration the System Configuration 578framework expects the prefix and a default router along with the 579configured address. As this extra information is not available via 580the DHCPv6 protocol the System Configuration framework isn't usable 581for address configuration, instead ifconfig is used directly. 582 583Note the Dynamic Store (from which /var/run/resolv.conf is built) is 584recomputed from scratch when the current location/set is changed. 585Running the dhclient-script reinstalls the resolv.conf.dhclient6 586configuration. 587 588 SUPPORT 589 590The Internet Systems Consortium DHCP server is developed and distributed 591by ISC in the public trust, thanks to the generous donations of its 592sponsors. ISC now also offers commercial quality support contracts for 593ISC DHCP, more information about ISC Support Contracts can be found at 594the following URL: 595 596 https://www.isc.org/services/support/ 597 598Please understand that we may not respond to support inquiries unless 599you have a support contract. ISC will continue its practice of always 600responding to critical items that effect the entire community, and 601responding to all other requests for support upon ISC's mailing lists 602on a best-effort basis. 603 604However, ISC DHCP has attracted a fairly sizable following on the 605Internet, which means that there are a lot of knowledgeable users who 606may be able to help you if you get stuck. These people generally 607read the dhcp-users@isc.org mailing list. Be sure to provide as much 608detail in your query as possible. 609 610If you are going to use ISC DHCP, you should probably subscribe to 611the dhcp-users or dhcp-announce mailing lists. 612 613WHERE TO SEND FEATURE REQUESTS: We like to hear your feedback. We may 614not respond to it all the time, but we do read it. If ISC DHCP doesn't 615work well for you, or you have an idea that would improve it for your 616use, please send your suggestion to dhcp-suggest@isc.org. This is also 617an excellent place to send patches that add new features. 618 619WHERE TO REPORT BUGS: If you want the act of sending in a bug report 620to result in you getting help in the form of a fixed piece of 621software, you are asking for help. Your bug report is helpful to us, 622but fundamentally you are making a support request, so please use the 623addresses described in the previous paragraphs. If you are _sure_ that 624your problem is a bug, and not user error, or if your bug report 625includes a patch, you can send it to our ticketing system at 626dhcp-bugs@isc.org. If you have not received a notice that the ticket 627has been resolved, then we're still working on it. 628 629PLEASE DO NOT REPORT BUGS IN OLD SOFTWARE RELEASES! Fetch the latest 630release and see if the bug is still in that version of the software, 631and if it is still present, _then_ report it. ISC release versions 632always have three numbers, for example: 1.2.3. The 'major release' is 6331 here, the 'minor release' is 2, and the 'maintenance release' is 3. 634ISC will accept bug reports against the most recent two major.minor 635releases: for example, 1.0.0 and 0.9.0, but not 0.8.* or prior. 636 637PLEASE take a moment to determine where the ISC DHCP distribution 638that you're using came from. ISC DHCP is sometimes heavily modified 639by integrators in various operating systems - it's not that we 640feel that our software is perfect and incapable of having bugs, but 641rather that it is very frustrating to find out after many days trying 642to help someone that the sources you're looking at aren't what they're 643running. When in doubt, please retrieve the source distribution from 644ISC's web page and install it. 645 646 HOW TO REPORT BUGS OR REQUEST HELP 647 648When you report bugs or ask for help, please provide us complete 649information. A list of information we need follows. Please read it 650carefully, and put all the information you can into your initial bug 651report. This will save us a great deal of time and more informative 652bug reports are more likely to get handled more quickly overall. 653 654 1. The specific operating system name and version of the 655 machine on which the DHCP server or client is running. 656 2. The specific operating system name and version of the 657 machine on which the client is running, if you are having 658 trouble getting a client working with the server. 659 3. If you're running Linux, the version number we care about is 660 the kernel version and maybe the library version, not the 661 distribution version - e.g., while we don't mind knowing 662 that you're running Redhat version mumble.foo, we must know 663 what kernel version you're running, and it helps if you can 664 tell us what version of the C library you're running, 665 although if you don't know that off the top of your head it 666 may be hard for you to figure it out, so don't go crazy 667 trying. 668 4. The specific version of the DHCP distribution you're 669 running, as reported by dhcpd -t. 670 5. Please explain the problem carefully, thinking through what 671 you're saying to ensure that you don't assume we know 672 something about your situation that we don't know. 673 6. Include your dhcpd.conf and dhcpd.leases file as MIME attachments 674 if they're not over 100 kilobytes in size each. If they are 675 this large, please make them available to us eg via a hidden 676 http:// URL or FTP site. If you're not comfortable releasing 677 this information due to sensitive contents, you may encrypt 678 the file to our release signing key, available on our website. 679 7. Include a log of your server or client running until it 680 encounters the problem - for example, if you are having 681 trouble getting some client to get an address, restart the 682 server with the -d flag and then restart the client, and 683 send us what the server prints. Likewise, with the client, 684 include the output of the client as it fails to get an 685 address or otherwise does the wrong thing. Do not leave 686 out parts of the output that you think aren't interesting. 687 8. If the client or server is dumping core, please run the 688 debugger and get a stack trace, and include that in your 689 bug report. For example, if your debugger is gdb, do the 690 following: 691 692 gdb dhcpd dhcpd.core 693 (gdb) where 694 [...] 695 (gdb) quit 696 697 This assumes that it's the dhcp server you're debugging, and 698 that the core file is in dhcpd.core. 699 700Please see https://www.isc.org/software/dhcp/ for details on how to subscribe 701to the ISC DHCP mailing lists. 702 703 HISTORY 704 705ISC DHCP was originally written by Ted Lemon under a contract with 706Vixie Labs with the goal of being a complete reference implementation 707of the DHCP protocol. Funding for this project was provided by 708Internet Systems Consortium. The first release of the ISC DHCP 709distribution in December 1997 included just the DHCP server. 710Release 2 in June 1999 added a DHCP client and a BOOTP/DHCP relay 711agent. DHCP 3 was released in October 2001 and included DHCP failover 712support, OMAPI, Dynamic DNS, conditional behaviour, client classing, 713and more. Version 3 of the DHCP server was funded by Nominum, Inc. 714The 4.0 release in December 2007 introduced DHCPv6 protocol support 715for the server and client. 716 717This product includes cryptographic software written 718by Eric Young (eay@cryptsoft.com). 719