Configuration procedure

Configure Router A:

# Specify the IP address of GigabitEthernet 1/0/1.

<RouterA> system-view
[RouterA] interface gigabitethernet 1/0/1
[RouterA-GigabitEthernet1/0/1] ip address 10.1.1.1 24
[RouterA-GigabitEthernet1/0/1] quit

# Enable DHCP.

[RouterA] dhcp enable

# Exclude an IP address from dynamic allocation.

[RouterA] dhcp server forbidden-ip 10.1.1.2

# Configure DHCP address pool 0. 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
[RouterA-dhcp-pool-0] expired day 10
[RouterA-dhcp-pool-0] dns-list 20.1.1.1
[RouterA-dhcp-pool-0] option 121 hex 181401010A010102

Configure Router B:

# Configure GigabitEthernet 1/0/1 to use DHCP for IP address acquisition.

<RouterB> system-view
[RouterB] interface gigabitethernet 1/0/1
[RouterB-GigabitEthernet1/0/1] ip address dhcp-alloc
[RouterB-GigabitEthernet1/0/1] quit