DHCP

1
DHCP

• Ana Chanaba
• Robert Huylo

2
DHCP Background / Server

• dhcpd - Dynamic Host Configuration Protocol
  Server
• allows hosts on a TCP/IP network to request and
  be assigned IP addresses from a pool defined in
  dhcpd.conf
• adds lease concept to BOOTP predecessor

3
DHCP Background / Server

• reads dhcpd.conf and assembles list of addresses
  for use in subnet
• allocates address following request
• assigns a lease to client
• records lease in dhcpd.leases
• server can keep lease states across boots
• renews expired leases for clients

4
DHCP Background / Client

• dhcpcd dhcp client
• gets host info (IP address, netmask, gateway,
  etc.) from a DHCP server
• lab1 134.198.161.101
• configures own network interface
• requests lease and lease renewals

5
DHCP Server Installation

• lab1.research.cs.uofs.edu
• Network Servers installation package
• dhcp-3.0.1-11

6
etc/dhcpd.conf

• option domain-name "lab1.research.cs.uofs.edu"
• option domain-name-servers 134.198.10.10,
  134.198.100.150
• default-lease-time 600
• max-lease-time 7200
• ddns-update-style ad-hoc
• subnet 134.198.161.0 netmask 255.255.255.0
• range 134.198.161.50 134.198.161.99
• option routers 134.198.161.254

7
Starting DHCP Server

• System Settings ?
• Server Settings ?
• Services ?
• dhcpd
• dhcrelay
• - dhcp servers on different subnets

8
var/lib/dhcp/dhcpd.leases

• lease 134.198.161.99
• starts 2 2005/03/01 184539
• ends 2 2005/03/01 185539
• tstp 2 2005/03/01 185539
• binding state free
• hardware ethernet 00c0f030d711
• uid "\001\000\300\3600\327\021"
• lease 134.198.161.98
• starts 4 2005/03/03 030159
• ends 4 2005/03/03 031159
• binding state active
• next binding state free
• hardware ethernet 00e04c96f395
• client-hostname "lab112.research.cs.uofs.edu"

9
References

• man pages dhcpd.conf, dhcpcd,
• dhcpd, dhcpd.leases
• DHCP RFC 2131 2132 -- R. Droms
• DHCP HOWTO Vladimir Vuksan
• www.linux.org
• Text Chp. 13.7