DHCP

Ana Chanaba

Robert Huylo

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

DHCP Background / Server

reads dhcpd.conf and assembles list of addresses for use in subnet

allocates address following requestassigns a lease to clientrecords lease in dhcpd.leases

server can keep lease states across bootsrenews expired leases for clients

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

DHCP Server Installation

lab1.research.cs.uofs.eduNetwork Servers installation packagedhcp-3.0.1-11

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;

}

Starting DHCP Server

System Settings Server Settings Services dhcpd

** dhcrelay

- dhcp servers on different subnets

var/lib/dhcp/dhcpd.leases

lease 134.198.161.99 { starts 2 2005/03/01 18:45:39; ends 2 2005/03/01 18:55:39; tstp 2 2005/03/01 18:55:39; binding state free; hardware ethernet 00:c0:f0:30:d7:11; uid "\001\000\300\3600\327\021";}lease 134.198.161.98 { starts 4 2005/03/03 03:01:59; ends 4 2005/03/03 03:11:59; binding state active; next binding state free; hardware ethernet 00:e0:4c:96:f3:95; client-hostname "lab112.research.cs.uofs.edu";}

References

man pages – dhcpd.conf, dhcpcd,

dhcpd, dhcpd.leasesDHCP RFC 2131 & 2132 -- R. DromsDHCP HOWTO – Vladimir Vuksan

www.linux.orgText – Chp. 13.7