linux -DHCP

Linux 7 DHCP+NAT

※ 環境設置

1. 防火牆

2. 網卡資訊

ens192:external (host only or NAT config)

ens224:internal (internal config)

3. /etc/sysctl.conf

# sysctl settings are defined through files in

# /usr/lib/sysctl.d/, /run/sysctl.d/, and /etc/sysctl.d/.

# Vendors settings live in /usr/lib/sysctl.d/.

# To override a whole file, create a new file with the same in

# /etc/sysctl.d/ and put new settings there. To override

# only specific settings, add a file with a lexically later

# name in /etc/sysctl.d/ and put new settings there.

# For more information, see sysctl.conf(5) and sysctl.d(5).

net.ipv6.conf.all.disable_ipv6=1

net.ipv6.conf.default.disable_ipv6=1

net.ipv4.ip_forward=1

sysctl -p

1. 安裝 dhcp 套件

yum install dhcp

yum list *dhcp*

2. 設定 dhcp.conf

cp /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example /etc/dhcp/dhcpd.conf

vi / etc/dhcp/dhcpd.conf

# A slightly different configuration for an internal subnet.

subnet 10.5.5.0 netmask 255.255.255.224 {

range 10.5.5.26 10.5.5.30;

option domain-name-servers ns1.internal.example.org;

option domain-name "internal.example.org";

option routers 10.5.5.1;

option broadcast-address 10.5.5.31;

default-lease-time 600;

max-lease-time 7200;

}

exam:

# A slightly different configuration for an internal subnet.

subnet 10.0.0.0 netmask 255.255.255.0 {

range 10.0.0.101 10.0.0.200;

option domain-name-servers 10.0.0.254, 168.95.1.1;

option domain-name "route";

option routers 10.0.0.254;

option broadcast-address 10.0.0.255;

default-lease-time 600;

max-lease-time 7200;

}

ex:設定固定IP

host passacaglia { #passacaglia 為自定義名字可以改成hostname或 host IP

hardware ethernet 00:50:FC:8E:D2:3D; //指定分配給此 MAC Address 的 DHCP Client 固定 IP

fixed-address 192.168.1.78; //指定分配給上述 MAC Address 的 DHCP Client 固定 IP 位址

}

3. 重啟dhcp

systemctl enable dhcpd

systemctl restart dhcpd

systemctl status dhcpd

4. NAT設定

firewall-cmd --permanent --direct --add-rule ipv4 nat POSTROUTING 0 -o ens192 -j MASQUERADE #public network interface

firewall-cmd --permanent --direct --add-rule ipv4 filter FORWARD 0 -i ens224 -o ens192 -j ACCEPT #dhcp ,private network interface

firewall-cmd --permanent --direct --add-rule ipv4 filter FORWARD 0 -i ens192 -o ens224 -m state --state RELATED,ESTABLISHED -j ACCEPT

firewall-cmd --reload

Client端以Window Server 2016測試

※ 網卡設定

※ 連線測試