interface loopback 0
 ip address 10.4.100.1 255.255.255.255
 ipv6 address 1234::10:4:100:1/128
 cdp enable
 no shutdown
interface serial 0
 description labf-s1
 ip address 10.4.1.1 255.255.255.252
 ipv6 address 1234::10:4:1:1/126
 clock rate 125000
 cdp enable
 no shutdown
interface serial 1
 description labe-s0
 ip address 10.5.1.2 255.255.255.252
 ipv6 address 1234::10:5:1:2/126
 cdp enable
 no shutdown
interface ethernet 0
 description cata1-fe8 (laba-e1)
 ip address 10.4.3.1 255.255.255.0
 ipv6 address 1234::10:4:3:1/120
 cdp enable
 no shutdown