In the following example, a VLAN interface is configured, and then the Dialer interface is configured with an unnumbered IP address, borrowing the IP address from the VLAN interface.
//enter the context of vlan interface 1:
Gxxx-001(super)# interface Vlan 1
//to configure the IP address of the vlan interface:
Gxxx-001(super-if:Vlan 1)# ip address 180.0.0.1 255.255.255.0
Gxxx-001(super-if:Vlan 1)# exit
Gxxx-001# !
//enter the context of the Dialer interface:
Gxxx-001(super)# interface dialer 1
Gxxx-001(super-if:Dialer 1)# dialer string 1 3001
Gxxx-001(super-if:Dialer 1)# dialer persistent delay 1
Gxxx-001(super-if:Dialer 1)# dialer modem-interface USB-modem
//to configure IP unnumbered on the Dialer interface, borrowing the IP address from vlan interface 1, configured above:
Gxxx-001(super-if:Dialer 1)# ip unnumbered 1 Vlan 1
Gxxx-001(super-if:Dialer 1)# exit
Gxxx-001(super)# !
The following sample routing table shows how routes discovered on unnumbered interfaces by routing protocols are listed as via routes in the Next-Hop column:
Network |
Mask |
Interface |
Next-Hop |
Cost |
TTL |
Source |
----------- |
----- |
------------- |
--------------- |
-------- |
----- |
--------- |
0.0.0.0 |
0 |
FastEth10/3 |
149.49.54.1 |
1 |
n/a |
STAT-HI |
2.2.2.0 |
24 |
Vlan15 |
2.2.2.1 |
1 |
n/a |
LOCAL |
10.0.0.0 |
8 |
Vlan1 |
0.0.0.40 |
1 |
n/a |
LOCAL |
3.0.0.0 |
8 |
Tunnel1 |
Via Dia.1 |
2 |
172 |
RIP |
4.0.0.0 |
8 |
Tunnel 1 |
Via Dia.1 |
2 |
172 |
RIP |
20.0.0.0 |
8 |
Tunnel 1 |
Via Dia.1 |
11112 |
n/a |
OSPF |
20.0.0.1 |
32 |
Tunnel 1 |
Via Dia.1 |
22222 |
n/a |
OSPF |
26.0.0.0 |
8 |
Vlan 15 |
2.2.2.2 |
3 |
n/a |
STAT-LO |
31.0.0.0 |
8 |
Serial 3/1:1.1 |
31.0.0.1 |
1 |
n/a |
LOCAL |
32.0.0.0 |
8 |
Serial 3/1:1.2 |
32.0.0.1 |
1 |
n/a |
LOCAL |
33.0.0.0 |
8 |
Serial 3/1:1.3 |
33.0.0.1 |
1 |
n/a |
LOCAL |
99.0.0.0 |
8 |
Vlan 99 |
99.1.1.1 |
1 |
n/a |
LOCAL |
135.64.0.0 |
16 |
FastEth 10/3 |
149.49.54.1 |
1 |
n/a |
STAT-HI |
138.0.0.0 |
8 |
Serial 3/1:1.1 |
Via Ser.3/1:1.1 |
2 |
n/a |
STAT-LO |
139.0.0.0 |
8 |
Serial 3/1:1.1 |
Via Ser.3/1:1.1 |
1 |
n/a |
STAT-LO |
149.49.54.0 |
24 |
FastEth 10/3 |
149.49.54.112 |
1 |
n/a |
LOCAL |
180.0.0.0 |
8 |
Loopback 1 |
180.0.0.1 |
1 |
n/a |
LOCAL |
