diff options
Diffstat (limited to 'docs/textdocs/DHCP-Server-Configuration.txt')
| -rw-r--r-- | docs/textdocs/DHCP-Server-Configuration.txt | 240 |
1 files changed, 0 insertions, 240 deletions
diff --git a/docs/textdocs/DHCP-Server-Configuration.txt b/docs/textdocs/DHCP-Server-Configuration.txt deleted file mode 100644 index 499706955f..0000000000 --- a/docs/textdocs/DHCP-Server-Configuration.txt +++ /dev/null @@ -1,240 +0,0 @@ -Subject: DHCP Server Configuration for SMB Clients -Date: March 1, 1998 -Updated: May 15, 2001 -Contributor: John H Terpstra <jht@samba.org> -Support: This is an unsupported document. Refer to documentation that is - supplied with the ISC DHCP Server. Do NOT email the contributor - for ANY assistance. -=============================================================================== - -Background: -=========== - -We wish to help those folks who wish to use the ISC DHCP Server and provide -sample configuration settings. Most operating systems today come ship with -the ISC DHCP Server. ISC DHCP is available from: - ftp://ftp.isc.org/isc/dhcp - -Incorrect configuration of MS Windows clients (Windows9X, Windows ME, Windows -NT/2000) will lead to problems with browsing and with general network -operation. Windows 9X/ME users often report problems where the TCP/IP and related -network settings will inadvertantly become reset at machine start-up resulting -in loss of configuration settings. This results in increased maintenance -overheads as well as serious user frustration. - -In recent times users on one mailing list incorrectly attributed the cause of -network operating problems to incorrect configuration of Samba. - -One user insisted that the only way to provent Windows95 from periodically -performing a full system reset and hardware detection process on start-up was -to install the NetBEUI protocol in addition to TCP/IP. This assertion is not -correct. - -In the first place, there is NO need for NetBEUI. All Microsoft Windows clients -natively run NetBIOS over TCP/IP, and that is the only protocol that is -recognised by Samba. Installation of NetBEUI and/or NetBIOS over IPX will -cause problems with browse list operation on most networks. Even Windows NT -networks experience these problems when incorrectly configured Windows95 -systems share the same name space. It is important that only those protocols -that are strictly needed for site specific reasons should EVER be installed. - -Secondly, and totally against common opinion, DHCP is NOT an evil design but is -an extension of the BOOTP protocol that has been in use in Unix environments -for many years without any of the melt-down problems that some sensationalists -would have us believe can be experienced with DHCP. In fact, DHCP in covered by -rfc1541 and is a very safe method of keeping an MS Windows desktop environment -under control and for ensuring stable network operation. - -Please note that MS Windows systems as of MS Windows NT 3.1 and MS Windows 95 -store all network configuration settings a registry. There are a few reports -from MS Windows network administrators that warrant mention here. It would appear -that when one sets certain MS TCP/IP protocol settings (either directly or via -DHCP) that these do get written to the registry. Even though a subsequent -change of setting may occur the old value may persist in the registry. This -has been known to create serious networking problems. - -An example of this occurs when a manual TCP/IP environment is configured to -include a NetBIOS Scope. In this event, when the administrator then changes the -configuration of the MS TCP/IP protocol stack, without first deleting the -current settings, by simply checking the box to configure the MS TCP/IP stack -via DHCP then the NetBIOS Scope that is still persistent in the registry WILL be -applied to the resulting DHCP offered settings UNLESS the DHCP server also sets -a NetBIOS Scope. It may therefore be prudent to forcibly apply a NULL NetBIOS -Scope from your DHCP server. The can be done in the dhcpd.conf file with the -parameter: - option netbios-scope ""; - -While it is true that the Microsoft DHCP server that comes with Windows NT -Server provides only a sub-set of rfc1533 functionality this is hardly an issue -in those sites that already have a large investment and commitment to Unix -systems and technologies. The current state of the art of the DHCP Server -specification in covered in rfc2132. - -This document aims to provide enough background information so that the -majority of site can without too much hardship get the Internet Software -Consortium's (ISC) DHCP Server into operation. The key benefits of using DHCP -includes: - -1) Automated IP Address space management and maximised re-use of available IP -Addresses, - -2) Automated control of MS Windows client TCP/IP network configuration, - -3) Automatic recovery from start-up and run-time problems with Windows95. - - - -Client Configuration for SMB Networking: -======================================== -SMB network clients need to be configured so that all standard TCP/IP name to -address resolution works correctly. Once this has been achieved the SMB -environment provides additional tools and services that act as helper agents in -the translation of SMB (NetBIOS) names to their appropriate IP Addresses. One -such helper agent is the NetBIOS Name Server (NBNS) or as Microsoft called it -in their Windows NT Server implementation WINS (Windows Internet Name Server). - -A client needs to be configured so that it has a unique Machine (Computer) -Name. - -This can be done, but needs a few NT registry hacks and you need to be able to -speak UNICODE, which is of course no problem for a True Wizzard(tm) :) -Instructions on how to do this (including a small util for less capable -Wizzards) can be found at - - http://www.unixtools.org/~nneul/sw/nt/dhcp-netbios-hostname.html - - -All remaining TCP/IP networking parameters can be assigned via DHCP. These include: - -a) IP Address, -b) Netmask, -c) Gateway (Router) Address, -d) DNS Domain Name, -e) DNS Server addresses, -f) WINS (NBNS) Server addresses, -g) IP Forwarding, -h) Timezone offset, -i) Node Type, -j) NetBIOS Scope - -Other assignments can be made from a DHCP server too, but the above cover the -major needs. - -Note: IF ever an entry has has been made to the NetBIOS Scope field of the -TCP/IP configuration panel on an MS Windows machine, and it has then been -committed, then that setting may become persistent. In such a c ase it is better -to configure the DHCP server with a NetBIOS Scope consisting of an empty string -(ie: A NULL scope). - - -DHCP Server Installation: -========================= -It is assumed that you will have obtained a copy of the GPL'd ISC DHCP server -source files from ftp://ftp.isc.org/isc/dhcp, it is also assumed that you have -compiled the sources and have installed the binary files. - -The following simply serves to provide sample configuration files to enable -dhcpd to operate. The sample files assume that your site is configured to use -private IP network address space using the Class B range of 172.16.1.0 - -172.16.1.255 and is using a netmask of 255.255.255.0 (ie:24 bits). It is -assumed that your router to the outside world is at 172.16.1.254 and that your -Internet Domain Name is bestnet.com.au. The IP Address range 172.16.1.100 to -172.16.1.240 has been set aside as your dynamically allocated range. In -addition, bestnet.com.au have two print servers that need to obtain settings -via BOOTP. The machine linux.bestnet.com.au has IP address 172.16.1.1 and is -you primary Samba server with WINS support enabled by adding the parameter to -the /etc/smb.conf file: [globals] wins support = yes. The dhcp lease time will -be set to 20 hours. - -Configuration Files: -==================== -Before dhcpd will run you need to install a file that speifies the -configuration settings, and another that holds the database of issued IP -addresses. On many systems these are stored in the /etc directory on the Unix -system. - -Example /etc/dhcpd.conf: -======================== -server-identifier linux.bestnet.com.au; - -subnet 172.16.1.0 netmask 255.255.255.0 { - range 172.16.1.100 172.16.1.240; - default-lease-time 72000; - max-lease-time 144000; - option subnet-mask 255.255.255.0; - option broadcast-address 172.16.1.255; - option routers 172.16.1.254; - option domain-name-servers 172.16.1.1, 172.16.1.2; - option domain-name "bestnet.com.au"; - option time-offset 39600; - option ip-forwarding off; - option netbios-name-servers 172.16.0.1, 172.16.0.1; - option netbios-dd-server 172.16.0.1; - option netbios-node-type 8; - option netbios-scope ""; -} - -; Note: The above netbios-scope is purposely an empty (NULL) string. - -group { - next-server 172.16.1.10; - option subnet-mask 255.255.255.0; - option domain-name "bestnet.com.au"; - option domain-name-servers 172.16.1.1, 172.16.0.2; - option netbios-name-servers 172.16.0.1, 172.16.0.1; - option netbios-dd-server 172.16.0.1; - option netbios-node-type 8; - option netbios-scope "SomeCrazyScope"; - option routers 172.16.1.240; - option time-offset 39600; - host lexmark1 { - hardware ethernet 06:07:08:09:0a:0b; - fixed-address 172.16.1.245; - } - host epson4 { - hardware ethernet 01:02:03:04:05:06; - fixed-address 172.16.1.242; - } -} - - -Creating the /etc/dhcpd.leases file: -==================================== -At a Unix shell create an empty dhcpd.leases file in the /etc directory. -You can do this by typing: cp /dev/null /etc/dhcpd.leases - - -Setting up a route table for all-ones addresses: -================================================ -Quoting from the README file that comes with the ISC DHCPD Server: - - BROADCAST - -In order for dhcpd to work correctly with picky DHCP clients (e.g., -Windows 95), it must be able to send packets with an IP destination -address of 255.255.255.255. Unfortunately, Linux insists on changing -255.255.255.255 into the local subnet broadcast address (here, that's -192.5.5.223). This results in a DHCP protocol violation, and while -many DHCP clients don't notice the problem, some (e.g., all Microsoft -DHCP clients) do. Clients that have this problem will appear not to -see DHCPOFFER messages from the server. - -It is possible to work around this problem on some versions of Linux -by creating a host route from your network interface address to -255.255.255.255. The command you need to use to do this on Linux -varies from version to version. The easiest version is: - - route add -host 255.255.255.255 dev eth0 - -On some older Linux systems, you will get an error if you try to do -this. On those systems, try adding the following entry to your -/etc/hosts file: - -255.255.255.255 all-ones - -Then, try: - - route add -host all-ones dev eth0 - - -For more information please refer to the ISC DHCPD Server documentation. |