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New Member

Cannot get DHCP working

I have a router I'm setting up for a branch office.  I got NAT and VPN working.  All good.  DHCP is failing me though.

Here's what I added to make the router do DHCP:

no ip dhcp use vrf connected

ip dhcp excluded-address 172.16.31.1 172.16.31.9

!

ip dhcp pool [pool-name]

   network 172.16.31.0 255.255.255.224

   default-router 172.16.31.5

I then went into int fa2 and did "no shutdown."

I also did "service dhcp" from config t, but I think I read that's already enabled.

But my laptop will not pull a DHCP address when I plug into int fa2.

I know the laptop is good bcs it pulls fine from the live network DHCP server when I retried it to see if it was the laptop.

ty

  • LAN Switching and Routing
7 REPLIES
Hall of Fame Super Silver

Cannot get DHCP working

You have given  us some information. But not enough to see what the problem is. The configuration of the DHCP pool looks ok. You tell us that you connect to fa2 but do not tell us how fa2 is configured. If you can tell us that we might be on the way to finding your problem.

HTH

Rick

New Member

Cannot get DHCP working

It is an 1811 router.  For fa2, I did, "no shutdown".

It looks like this:

interface FastEthernet2

!

Is there more?

Cannot get DHCP working

Hi,

Fa2 should be in the same subnet as ip dchp pool or in vlan that is in the same subnet as the pool.

Best regards,

Alex

New Member

Cannot get DHCP working

In other 1811 configs I've found online with DHCP, the client interfaces look the same.  I tried giving fa2 an ip and got this:

(config-if)#ip address 172.16.31.6 255.255.255.224

% IP addresses may not be configured on L2 links.

I'm not setting any vlans and/or, it should have the access vlan gtg right?

I can set a static IP on the laptop and it works great.  Just not DHCP.

Purple

Cannot get DHCP working

Hi,

From the output you got when trying to configure an ip address, the port is a switch port and so you must configure the correct vlan interface with an  ip address

Regards.

Alain

Don't forget to rate helpful posts.
Hall of Fame Super Silver

Cannot get DHCP working

Based on what you have told us so far the fa2 interface is a layer 2 switch port. So it would default to be in VLAN 1. So you need to configure VLAN 1. And since your DHCP says the default router is 172.16.31.5 then this needs to be the IP address assigned to VLAN 1.

HTH

Rick

Cannot get DHCP working

Hi,

In addition to what Alain and Rick said:

config t

int vlan1

ip address 172.16.31.5  255.255.255.224  (if is not used somewhere else, then you have to modify  maybe your config)

exit

Best regards,

Alex

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