Cisco 881W DHCP and VLANS

[jsrobison]

Hey everybody.  First time poster facing a very infuriating issue (at least for me, because I've been working on this for the last 4 days and have gotten no where).  I am trying to set up a lab enviroment where I have three networks (172.x.x.x, 192.x.x.x, 10.x.x.x) which connect to three unmanaged switches; one switch per network.  I am also trying to configure DHCP on this router to where if I plug in a device to FastEthernet 0 or FastEthernet 3, it gets a 172.x.x.x address from DHCP.  FastEthernet 1 gets a 192.x.x.x address, and FastEthernet 2 gets a 10.x.x.x address.  Here's the tricky part. When I tell the router "switchport access vlan x" and then "ip add 172.x.x.x 255.255.254.0", I get the correct network address for that port.  The problem is I want all of the networks to be able to talk to each other.  The only way that I know to do that is through a trunk.  Once I set the ports up on a trunk, they lose the ability to get a DHCP address.  Any help would be greatly appreciated. 

-Justin

[Iliya Gatsev · Accepted solution]

Hi,
My name is Iliya Gatsev from Cisco Technical Support Team.

The 800 series routers are not considered Small Business devices so I can suggest to post your question in the Network Infrastructure section to get to resolution quicker.

Please rate this post or marked as answered to help other Cisco customers.

Iliya Gatsev
Cisco STAC Network Engineer
Together we are the human network .:|:.:|:. CISCO