R1
[R1]isis
[R1-isis-1]network-entity 49.0001.0000.0000.0001.00
[R1-isis-1]int e0/0/0
[R1-Ethernet0/0/0]isis enable
[R1-Ethernet0/0/0]ip ad 12.1.1.1 24
[R1-Ethernet0/0/0]int e0/0/1
[R1-Ethernet0/0/1]ip ad 12.1.2.254 24
[R1-Ethernet0/0/1]isis enable
R2
[R2]isis
[R2-isis-1]network-entity 49.0001.0000.0000.0002.00
[R2-isis-1]int e0/0/0
[R2-Ethernet0/0/0]isis enable
[R2-Ethernet0/0/0]ip ad 12.1.1.2 24
[R2-Ethernet0/0/0]int e0/0/1
[R2-Ethernet0/0/1]ip ad 12.1.3.254 24
[R2-Ethernet0/0/1]isis enable