Re: AP 1200 dhcp relay features

dtongue · ‎08-08-2004

hi

i am trying to setup our firm wireless network by configuring the 10 AP 1200 series we have to act like dhcp relay.

does anyone know how i can do that?

one's of my AP 1200 configuration file looks like :

ip dhcp smart-relay

ip dhcp relay information option

ip dhcp relay information trust-all

!

ip dhcp-server x.x.x.x

but it does'nt work!

thanks

kmarrero · ‎08-09-2004

I believe you have to put "ip dhcp relay information trusted" under the VLAN or interface on the AP.

paddyxdoyle · ‎08-09-2004

Hi,

I have just implemented similar.

All you need to do is under your BVI1 interface add the address of your DHCP server using "ip helper-address IP_of_DHCP_Server"

#sh run int BVI1

Building configuration...

Current configuration : 116 bytes

!

interface BVI1

ip address x.x.x.x x.x.x.x

ip helper-address x.x.x.x

no ip route-cache

end

Rgds

Paddy

dtongue · ‎08-09-2004

thanks for the advice

it works!!

Un0riginal · ‎08-18-2004

Paddy,

Wonder if you might be able to shed some light on my problem, after reading your suggestion I put that configuration in. That kept timing out when the wireless laptop was attempting to connect, so added the other 3 DHCP servers in as well.

As below

#show run int bvi1

Building configuration...

Current configuration : 214 bytes

!

interface BVI1

ip address dhcp client-id FastEthernet0

ip helper-address xxx.xxx.xx6.140

ip helper-address xxx.xxx.xx6.193

ip helper-address xxx.xxx.xx7.145

ip helper-address xxx.xxx.xx7.146

no ip route-cache

end

still getting time out

any suggestions would be gratefully received

cheers

Daryl

*******EDIT********

Just for kicks and giggles reset the router to defaults. With ip helper and no security will allow dhcp requests to be passed back and forth.

Any idea how I set it to still go through with encription and mac authentication (all local list no radius servers)

paddyxdoyle · ‎08-19-2004

Daryl,

You need to check your security settings as it you can't authenticate with your AP then you won't get a IP address etc. What security are you using?

Rgds

Paddy

Un0riginal · ‎08-19-2004

Paddy,

Using 128bit Hex WEP, the key being pushed out by the AP. The client appears to authenticate fine, it connects and alleges to have strong signal strength but I have noticed a lack of traffic between the two when it is authenticated, would assume it should still be sending and receiving some broadcast packets.

**Update**

Don't I feel stupid, just as I was typing this out I realised that I had just been ticking 'the key is provided for me box' and not tried just putting it in manually on the client. This done and the client now connects fine. Is there an inherent problem with telling the client that the key is provided? I thought that was the whole point of having the 'transmit key' radio button

Regards

Daryl

**edit** forgot to add, leaving rest of text in there in case anyone has similar problem and can skip the embarrasing step of asking and then finding out it works :P

steveb_coda · ‎09-21-2004

I'm having a similar problem with about the same configuration. My security is set to 40bit Hex WEP. Anything over 10 connections, the 11th can see the AP but can't get an IP from it.

I've configured the AP with a Static IP, maybe I should set it DHCP? We have a DHCP server, I just figured I'd need to assign the AP a Static so I can admin it.

Any help greatly appreciated!

paddyxdoyle · ‎09-22-2004

Steve,

You should keep your AP on a static address as if your DHCP server was out of action you would have no inband access to your AP, DHCP should only be used for your clients.

Are you currently using DHCP from your AP or your DHCP server?

How big is the DHCP scope you created?

It sounds like you have run out of available

addresses in your scope.

HTH

Paddy

steveb_coda · ‎09-22-2004

Hey Paddy,

I thought so on leaveing the AP with Static.. thanks for verifying that for me. DHCP comes from the server not the AP. Do I have to configure the scope from the server that gets passed through the AP or is there a setting on the AP that allows so many IPs to passthrough by default?

Steve

paddyxdoyle · ‎09-22-2004

Hi,

Its all done on your server

In your scenario, the AP doesn't get involved in the actual allocating of the IPs, if just relays the DHCP request to your DHCP server using the IP helpder address.

I would check the size of the scope on your server.

Rgds

Paddy

steveb_coda · ‎09-22-2004

DCHP scope has plenty. 153 IPs to lease out, we are a small office of 30 employees with at the most 60 IPs leased. DHCP works fine with everyone connected via hard LAN, but when we go wireless, the fist 10 get on. The rest get windows XP default IP.

Anything else I can look at? Maybe change the IP of the AP to a lower address instead of the top IP? That shouldn't matter...should it?

Un0riginal · ‎09-22-2004

Steve,

Paddy told you to use the iphelper, this forwards all DHCP requests received on the router. this is set on the on the interface (enable, configure terminal, interface BVI 1,iphelper xxx.xxx.xxx.xxx)You can have multiple iphelper address, to take one out you just use the no form of the command (no iphelper xxx.xxx.xxx.xxx)

Daryl

steveb_coda · ‎09-23-2004

Chaging encryption seems to have helped tremendously. I've been reading alot of posts about how people have taken encryption completely off and they get IPs so I chenged from 40 to 128 (good idea anyway) And went from WEP to Cipher Mode. Cipher is set to TKIP + WEP 128 bit. I now have 13 IPs passing through and as more users are coming in this morning I'm updating thier key and they are getting IPs!

This post is FYI incase any other have experienced similar issues. Thanks to all who helped.

Steve