002. DHCP Configuration

A DHCP Server Installation Package

  1 yum -y install dhcp

2. Corresponding Port

IPv4 udp67 and udp68

IPv6 udp546 and udp547

3. File Path

Service name: DHCPD

• Main configuration file:/etc/DHCP/DHCPD. conf
• Template File:/usr/share/doc/DHCP */DHCPD. conf. Example

Iv. configuration file 4.1 common configuration items

1 option domain-name # Set the DNS domain 2 3 option domain-name-servers # Set the DNS server address 4 5 default-lease-time # Set the default lease time, in seconds 6 7 max-lease-time # sets the maximum lease time, in seconds 8 9 ddns-Update-style # sets the DNS update mode, generally, 10 11 authoritative # is not used to identify the authoritative server. The valid identifier 12 13 log-facility local7 # is sent to the local7 Log service.

5. modify configuration items on the server side of instance 5.1

Note: To make the configuration clear, you can delete unnecessary subnet items and only retain the items to be configured. If you do not need to configure DHCP for a specific host, you can also delete the host items.

1 option domain-name-servers 61.153.177.198, 223.5.5.5; # global DNS configuration 2 3 default-lease-time 7200; # global minimum lease time 4 5 max-lease-time 14400; # global maximum lease time 6 7 subnet 192.168.10.0 netmask 255.255.255.0 {# Set CIDR Block 8 9 Range 192.168.10.11 192.168.10.254; # Set the allocable address pool 10 11 option domain-name-servers 61.153.177.198, 223.5.5.5 # It can be configured globally and globally. It can also be configured under subnet. It only takes effect for a specific subnet 12 13 option routers 192.168.10.2; # Set the gateway 14 15 option broadcast-address 192.168.10.255; # broadcast 16 17}

5.2 restart the dncp service on the server

1 [[email protected] DHCP] service DHCPD restart # centos6. * series commands 2 3 [[email protected] DHCP] systemctl restart DHCPD # centos7 series commands

5.3 set the client to DHCP for retrieval

  1 TYPE=Ethernet  2   3 BOOTPROTO=dhcp  4   5 DEFROUTE=yes  6   7 NAME=eth0  8   9 ONBOOT=yes

5.4 restart the client NETWORK SERVICE

  1 [[email protected] ~]systemctl restart network

5.5 check and verify the client

[[Email protected] ~] # Ifconfig

Eth0: Flags = 4163 <up, broadcast, running, multicast> MTU 1500

Inet 192.168.10.11 netmask 255.255.255.0 broadcast 192.168.10.255

......

5.6 view lease information of a service

  1 [[email protected] dhcp]# cat /var/lib/dhcpd/dhcpd.leases  2   3 # The format of this file is documented in the dhcpd.leases(5) manual page.  4   5 # This lease file was written by isc-dhcp-4.2.5  6   7 server-duid "\000\001\000\001\037S(\244\000\014)\371Xn";  8   9 lease 192.168.10.11 { 10  11 starts 5 2016/08/26 16:25:24; 12  13 ends 5 2016/08/26 18:25:24; 14  15 cltt 5 2016/08/26 16:25:24; 16  17 binding state active; 18  19 next binding state free; 20  21 rewind binding state free; 22  23 hardware ethernet 00:50:56:36:ad:b9; 24  25 client-hostname "imxhy"; 26  27 }

Appendix:

Obtain the DHCP Client address:

  1 tail -n +4 /var/lib/dhcpd/dhcpd.leases | less | grep -v ‘server-duid‘ | awk ‘BEGIN{RS=ORS="}"}{print $2,$25,$29"\n"}‘ | sed ‘s/}//g‘ | sed ‘s/;//g‘ | sed ‘s/"//g‘ | sort -n | column -t

002. DHCP Configuration