259Configuration exampleNetwork requirementsAs shown in Figure 107, the two subnets Group 1 and Group 2 use private IPv4 addresses. Configure anIPv4 over IPv4 tunnel between Router A and Router B to make the two subnets reachable to each other.Figure 107 Network diagramConfiguration procedureMake sure Router A and Router B can reach each other through IPv4.• Configure Router A:# Specify an IPv4 address for Ethernet 1/1. system-view[RouterA] interface ethernet 1/1[RouterA-Ethernet1/1] ip address 10.1.1.1 255.255.255.0[RouterA-Ethernet1/1] quit# Specify an IPv4 address for Serial 2/0, which is the physical interface of the tunnel.[RouterA] interface serial 2/0[RouterA-Serial2/0] ip address 2.1.1.1 255.255.255.0[RouterA-Serial2/0] quit# Create an IPv4 over IPv4 tunnel interface tunnel 1.[RouterA] interface tunnel 1 mode ipv4-ipv4# Specify an IPv4 address for the tunnel interface.[RouterA-Tunnel1] ip address 10.1.2.1 255.255.255.0# Specify the IP address of Serial 2/0 as the source address for the tunnel interface.[RouterA-Tunnel1] source 2.1.1.1# Specify the IP address of Serial 2/0 on Router B as the destination address for the tunnelinterface.[RouterA-Tunnel1] destination 3.1.1.1[RouterA-Tunnel1] quit# Configure a static route destined for the IP network Group 2 through the tunnel interface.[RouterA] ip route-static 10.1.3.0 255.255.255.0 tunnel 1• Configure Router B:# Specify an IPv4 address for Ethernet 1/1. system-view[RouterB] interface ethernet 1/1[RouterB-Ethernet1/1] ip address 10.1.3.1 255.255.255.0
