1 / 10

DHCP server & Client

DHCP server & Client. Objectives to learn how to setup dhcp servers Contents Download and Install The DHCP Package The /etc/dhcpd.conf File Upgrading Your DHCP Server How to get DHCP started Modify Your Routes for DHCP on Linux Server Configuring Linux clients to use DHCP

ranit
Télécharger la présentation

DHCP server & Client

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DHCP server & Client • Objectives • to learn how to setup dhcp servers • Contents • Download and Install The DHCP Package • The /etc/dhcpd.conf File • Upgrading Your DHCP Server • How to get DHCP started • Modify Your Routes for DHCP on Linux Server • Configuring Linux clients to use DHCP • Simple DHCP TroubleshootingPracticals • working with TCP/IP utilities and files

  2. Download and Install The DHCP Package • You have three ways to install DHCP server on RedHat • With yum/up2date (install sample config and prepare lease data base) • RPM (Simply install it, togeather with sample config) • You need at least RPM-package dhcp-server if you download manually • TAR-BALL (Allways latest version, the ISC standard dhcp, manual work) • Getting the DHCP server with yum • Will download and start configure DHCP • Installing from RPM’s • You can also obtain dhcp sources directly from ISC The version rpm number is dhcp-3.0.2-6in our example, and 3.0.3 for the tar ball. # yum install dhcp-server # rpm –ivh dhcp-3.0.2-6.i586.rpm # rpm –ivh dhcp-server-3.0.2-6.i586.rpm # cd /usr/local/src #wget ftp://ftp.isc.org/isc/dhcp/dhcp-3.0.3.tar.gz

  3. The /etc/dhcpd.conf File basics • Sample dhcpd.conf file: /usr/share/doc/dhcp-<version-number>/dhcpd.conf.sample Their version number is dhcp-3.0pl1-23 in this example • Begin with the sample configuration file • Basic file format # cp /usr/share/doc/dhcp-3.0pl1-23/dhcpd.conf.sample \   /etc/dhcpd.conf subnet 192.168.1.0 netmask 255.255.255.0 { default-lease-time 86400; max-lease-time 86400; option routers 192.168.1.100; option log-servers 192.168.1.100; option broadcast-address 192.168.1.255; option domain-name-servers 192.168.1.100, 80.84.37.3; option nntp-server 192.168.1.100; range 192.168.1.201 192.168.1.220; }

  4. The /etc/dhcpd.conf File fix/denial • Deliver fixed address to a host • Dont do DHCP on all interfaces/subnets if multihomed • TFTP boot server and boot loader file host printer { hardware ethernet 00:50:DA:38:CE:23; fixed-address 192.168.1.64; option domain-name-servers 192.168.1.100; option broadcast-address 192.168.1.255; option domain-name "printer.ikea.se"; } subnet 80.84.37.0 netmask 255.255.255.240 { not authoritative; } next-server 192.168.1.60; # tftp-server filename "pxelinux.0"; # bootloader host brutebert { hardware ethernet00:B0:D0:39:63:8C; }

  5. Dynamic DNS & DHCP • This is not the full story, DNS is also needed • You will need a DNS in order to update zonefiles • Main entries in /etc/dhcpd.conf • You also need one authorized key to allow updates • These entries comes before any subnet declaration authoritative; ddns-update-style interim; ddns-domainname "radio.ing-steen.se"; update-static-leases on; key "DHCP-UPDATER" { algorithm HMAC-MD5; secret ”<keydata>"; }

  6. Dynamic DNS & DHCP • The Forward and Reverse name Zone-files to update • They came after the ddns entries in same file. • Zones must be specified to the DHCP • Last comes the standard subnet declaration, like on page 3 with this added to it zone radio.ing-steen.se. { primary 172.16.0.5; key DHCP-UPDATER; } zone 16.172.in-addr.arpa. { primary 172.16.0.5; key DHCP-UPDATER; } authoritative; get-lease-hostnames true; do-forward-updates true; allow unknown-clients; ddns-updates on;

  7. Upgrading Your DHCP Server • When updating Look in header of sample file: /usr/share7doc/dhcp<version>/dhcpd.conf.sample Add those lines in your existing /etc/dhcpd.conf file ddns-update-style interim # Redhat Version 8.0+ ignore client-updates # Fedora Core 1+

  8. How to get DHCP started • DHCPD is depending on /var/lib/dhcp/dhcpd.leases You might need to erase existing lease files and create an empty: dhcpd.leases contain leases database format when in action: • Starting the dhcpd server • Stoppinig and Reloading the server # rm –f /var/lib/dhcp/dhcpd.leases # touch /var/lib/dhcp/dhcpd.leases lease 172.16.0.67 { starts 0 2004/09/05 04:41:09; ends 1 2004/09/06 04:41:09; hardware ethernet 00:0d:93:83:8a:8e; uid 01:00:0d:93:83:8a:8e; } # chkconfig dhcpd on # service dhcpd start # service dhcpd stop # service dhcpd restart

  9. Modify Your Routes for DHCP on Linux Server • Temporary solution Add the route to 255.255.255.255 from the command line If the message 255.255.255.255: Unknown host appears then try adding the following entry to your /etc/hosts file: Then, try: • Permanent solution add in /etc/sysconfig/static-routes If this doesn't work properly try adding the following entry to your /etc/hosts file: # route add -host 255.255.255.255 dev eth0 255.255.255.255 dhcp # route add -host dhcp dev eth0 eth0 host 255.255.255.255 255.255.255.255 dhcp

  10. Summary • DHCP server is used to deliver IP parameters • Configuration sit in /etc/dhcpd.conf • Leases sit in /var/lib/dhcp/dhcpd.leases • DHCP can deliver boot strap files to diskless • With options you can deliver many functions • DHCP server usally run as stand alone server • Start dhcp server with /etc/init.d/dhcpd start • Stop dhcp server with /etc/init.d/dhcpd stop • Reload dhcp server with /etc/init.d/dhcpd restart

More Related