ip unnumbered with 2 FE Ints?

Unanswered Question
Jan 29th, 2008
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Hi,


Is it possible to use ip unnumbered on fasteth interfaces?


With the following config, if we connect a device with 192.168.122.2/24 to FE 0/0 we are unable to ping 192.168.122.1?


interface FastEthernet0/0

no ip address

duplex auto

speed auto

!

interface FastEthernet0/0.1

ip unnumbered FastEthernet0/1

!

interface FastEthernet0/1

ip address 192.168.122.1 255.255.255.0

duplex auto

speed auto



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Richard Burts Tue, 01/29/2008 - 15:21
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What kind of device is it and how is it connected to FA0/0?


The use of ip unnumbered was originally restricted to point to point serial interfaces. Cisco has extended the concept and now you can configure VLAN subinterfaces of a router as ip unnumbered. This presumes that the connection on the interface is a trunk. So is the device that is connected doing trunking?


HTH


Rick

wazza_bayer Tue, 01/29/2008 - 16:06
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The device currently connected to FA0/0 is simply a Laptop - We will be connecting the router(1841) to a cisco switch and running dot1q.


So, if we have somthing like:


interface FastEthernet0/0.10

encapsulation dot1Q 10

ip unnumbered FastEthernet0/1


With vlan 10 running on switch port, and a trunk port back to 1841 FA0/0, it should work?

Richard Burts Tue, 01/29/2008 - 19:56
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I believe that this should work.


HTH


Rick

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