R3721-F3210-F3171-HP High-End Firewalls Network Management Configuration Guide-6PW101

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DHCP client configuration example
Network requirements
As shown in Figure 118, on a LAN, the Firewall contacts the DHCP server via GigabitEthernet 0/1 to
obtain an IP address, DNS server address, and static route information. The IP address resides on
network 10.1.1.0/24. The DNS server address is 20.1.1.1. The next hop of the static route to network
20.1.1.0/24 is 10.1.1.2.
The DHCP server uses Option 121 to assign static route information to DHCP clients. Figure 117 sh
ow
s the
format of Option 121. The destination descriptor field comprises two parts, subnet mask length and
destination network address. In this example, the value of the destination descriptor field takes 18 14 01
01, a hexadecimal number indicating that the subnet mask length is 24 and destination network address
is 20.1.1.0, and the value of the next hop address field takes 0A 01 01 02, a hexadecimal number
indicating that the next hop is 10.1.1.2.
Figure 117 Option 121 format
Figure 118 Network diagram
Configuration procedure
• Configure Router A
# Specify the IP address of GigabitEthernet 0/1.
<RouterA> system-view
[RouterA] interface GigabitEthernet 0/1
[RouterA-GigabitEthernet0/1] ip address 10.1.1.1 24
[RouterA-GigabitEthernet0/1] quit
# Enable DHCP.
[RouterA] dhcp enable
# Exclude an IP address from automatic allocation.
[RouterA] dhcp server forbidden-ip 10.1.1.2
# Configure DHCP address pool 0 and specify the subnet, lease duration, DNS server address,
and a static route to subnet 20.1.1.0/24.
[RouterA] dhcp server ip-pool 0
[RouterA-dhcp-pool-0] network 10.1.1.0 mask 255.255.255.0
Firewall
DHCP Client
DNS server
Router A
DHCP server
GE0/1
10.1.1.1/24
GE0/1
Router B
10.1.1.2/24 20.1.1.2/24
20.1.1.1/24