RHCE Study Notes DHCP

This RHCE Study Notes include common dhcp applications, assigned fixed ip addresses, relay proxy 1. in the experiment environment, set up four CentOS5.4 virtual machines, which are S (dhcpserver), A (dhcp-client), R (route), and B (relay proxy) Nic configurations as follows: /etc/sysconfig/network-scripts/The ifcfg-eth0 or eth1S: DEVICE = eth0 & n

This RHCE Study Notes include common dhcp applications, assigned fixed ip addresses, and relay proxies.

1. Set up an experiment environment
Four CentOS5.4 virtual machines, namely S (dhcpserver), A (dhcp-client), R (route), and B (relay proxy)
Nic configuration:/etc/sysconfig/network-scripts/ifcfg-eth0 or eth1
S: DEVICE = eth0
BOOTPRTO = static
HWADDR = XX: XX
ONBOOT = yes
IPADDR = 192.168.8.2
NETMASK = 255.255.255.0
GATEWAY = 192.168.8.1 (required by the relay proxy)
A: DEVICE = eth0
BOOTPRTO = dhcp
ONBOOT = yes
HWADDR: 00: 0C: 29: 0A: 4B: EE (required for fixed IP addresses)
R: DEVICE = eth0
BOOTPRTO = static
HWADDR = XX: XX
IPADDR = 192.168.8.1
NETMASK = 255.255.255.0

DEVICE = eth1
BOOTPRTO = static
HWADDR = XX: XX
IPADDR = 192.168.38.1
NETMASK = 255.255.255.0
B: DEVICE = eth0
BOOTPRTO = static
HWADDR = XX: xX: XX: xX
IPADDR = 192.168.38.2
NETMASK = 255.255.255.0
GATEWAY = 192.168.38.1
2. topology structure description:
The Virtual Machine S is located on the 192.168.8.x network segment, and the gateway is the IP address of the Virtual Machine R eth0.
Virtual Machine B is located on the 192.168.38.x network segment, and the gateway is the IP address of the Virtual Machine R eth1
Virtual Machine R acts as a router, so configure forwarding:
Check whether the NIC can forward data
Cat/proc/sys/net/ipv4/ip_forward
Echo "1">/proc/sys/net/ipv4/ip_forward
Try Virtual Machine B to ping dhcp server S after setting successful
Vm a and S are in the same network segment (VMnet2) first)
2. Install the dhcp package
Because the dhcp package contains dhcp services for the relay service, the virtual machine S Virtual Machine B needs to be installed.
Rpm-ivh dhcp-xxxx.rpm
Copy configuration file dhcp
Cp/usr/share/doc/dhcp-3.0xx/dhcpd. conf. sample/etc/dhcpd. conf
Relay Service dhcrelay does not need to copy the configuration file

3. Configure dhcpd. conf for virtual machine S
Vi/etc/dhcpd. conf
Ddns-update-style interim;
Ignore client-updates;
Subnet 192.168.8.0 netmask 255.255.255.0 {
 
# --- Default gateway
Option routers 192.168.8.1;
Option subnet-mask limit 255.0;
 
# Option nis-domain "domain.org ";
# Option domain-name "domain.org ";
# Option domain-name-servers 192.168.13.220;
 
Option time-offset-18000; # Eastern Standard Time
# Option ntp-servers 192.168.1.1;
# Option netbios-name-servers 192.168.1.1;
# --- Selects point-to-point node (default is hybrid). Don't change this unless
# -- You understand Netbios very well
# Option netbios-node-type 2;

Range dynamic-bootp 192.168.8.120 192.168.13.167; (set the address pool here)
Range dynamic-bootp 192.168.8.169 192.168.13.254; (168 reserved for a specific mac)
Default-lease-time 21600;
Max-lease-time 43200;

# We want the nameserver to appear at a fixed address
Host ns {
Next-server marvin.RedHat.com;
Hardware ethernet 00: 0C: 29: 0A: 4B: EE; (Reserved IP addresses for A specific mac are reserved for vm)
Fixed-address 192.168.8.168;
}
}