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Cisco Subinterfaces on 1841

I have a Cisco 1841 router that connects to a point-to-point T1 line.  The T1 connects a branch office to the main office.  The network at the main office is  The network at the branch office is  If you are on the network you have access to all the network resources of the main office and you are unrestricted.  However I would like to create a network at the branch office as well.  Anyone on this network will only have access to the internet and nothing else.  I will accomplish this through access lists.  Right now I have two separate vlans 91 and 93 setup as subinterfaces on the router.  I noticed that the 1841 router supports vlans just like a catalyst switch.  Should I use the subinterfaces or could I configure the router to use the vlans differently?  Instead of having a subinterface I could have an interface vlan 91 and so on?  Thanks for the help!


interface FastEthernet0/1.91
 encapsulation dot1Q 91
 ip address
interface FastEthernet0/1.93
 encapsulation dot1Q 93
 ip address
1 Solution
As long as the switchport that this router is connected to has the vlans set up, then what you have is perfectly fine.
The vlan support in the router is meant to be used with a 4-port 10/100 switch module. You can create vlan's on the switch.
You could also use one physical interface for each vlan instead of subinterfaces, plugging two cables into your switch, each switch/router port in access mode, assigned to the proper vlan, instead of a single uplink to the router in trunk mode.
molardAuthor Commented:
Thanks for the help :-)
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