Passing DHCP through a wireless AP (Cisco Aironet)

  • Thread starter Thread starter Jack B. Pollack
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J

Jack B. Pollack

I have a Cisco Aironet 1100 wireless access point. I have given it a fixed
IP address (Network Interface - IP Addresses - Static IP).

Some of my wireless computers require fixed IP's for ports that are being
forwarded to them. Other wireless PC can/do have dynamic IP's.

Problem is that the AP is not broadcasting the DHCP from the router.

Anyone know in general, or specifically for this AP if there is a setting,
or service that I have to enable so that SOME of the wireless PCs can use &
see the DHCP server through the AP (I want the AP to still have a static
address)?

Thanks
 
We have several of these APs. They do not support DHCP. you need a 3rd
party authentication software to do DHCP.
 
We have several of these APs. They do not support DHCP. you need a 3rd
party authentication software to do DHCP.
Click to expand...

Eh?

Where would this "3rd party authentication software" execute to get around a
WAP that not only doesn't provide a DHCP server itself, it supposedly doesn't
even pass through DHCP requests from its own clients, and responses from, say,
the router that the WAP is plugged into?

One of us must be confused (and yeah, it might be me ;-)
Perhaps those WAPs don't *provide* DHCP services, but it's hard to imagine why
one would even attempt to market a WAP that didn't pass through DHCP
traffic...

/daytripper
 
I have a Cisco Aironet 1100 wireless access point. I have given it a fixed
IP address (Network Interface - IP Addresses - Static IP).

Some of my wireless computers require fixed IP's for ports that are being
forwarded to them. Other wireless PC can/do have dynamic IP's.

Problem is that the AP is not broadcasting the DHCP from the router.

Anyone know in general, or specifically for this AP if there is a setting,
or service that I have to enable so that SOME of the wireless PCs can use &
see the DHCP server through the AP (I want the AP to still have a static
address)?

Thanks
Click to expand...

The following is excerpted from your WAPs installation guide, which can be
seen at

http://www.cisco.com/en/US/products...figuration_guide_chapter09186a008010234f.html

=============================================================
"If the access point is configured with default values and not connected to a
DHCP server or cannot obtain an IP address, it defaults to IP address 10.0.0.1
and becomes a mini-DHCP server. In that capacity, the access point provides up
to twenty IP addresses between 10.0.0.11 and 10.0.0.30 to the following
devices:

- An Ethernet-capable PC connected to its Ethernet port
- Wireless client devices configured to use either no SSID or tsunami as the
SSID, and with all security settings disabled.

The mini-DHCP server feature is disabled automatically when you assign a
static IP address to the access point."
==============================================================

So, that isn't a TOTAL piece of crap router. You *can* configure it so
wireless clients can be granted IP addresses via DHCP.
You just have to have your wireless segment exist in a specific subnet ;-)

hth

/daytripper
 
So it sounds like If I assign my own IP to the AP it wont act as a DHCP
server and more importantly wont pass DHCP from the router.

Any way around this (like to pass DHCP from the router through)?

Thanks

 
daytripper said:
Eh?

Where would this "3rd party authentication software" execute to get around a
WAP that not only doesn't provide a DHCP server itself, it supposedly doesn't
even pass through DHCP requests from its own clients, and responses from, say,
the router that the WAP is plugged into?

One of us must be confused (and yeah, it might be me ;-)
Perhaps those WAPs don't *provide* DHCP services, but it's hard to imagine why
one would even attempt to market a WAP that didn't pass through DHCP
traffic...

/daytripper
Click to expand...

I am not entirely sure either, when the consultants came in to install our
APs and such, we had to call them back because of the problem. they said it
was something about LEAP that made it so it can forward DHCP requests only
after you authenticate with the Radius Server.

I could be also confused myself. 4 days trying to rescue Exchange 2000 can
make one confused...crazy...even homicidal!
 
Jack B. Pollack said:
So it sounds like If I assign my own IP to the AP it wont act as a DHCP
server and more importantly wont pass DHCP from the router.

Any way around this (like to pass DHCP from the router through)?

Thanks
Click to expand...
<snip>

You could set the access point to obtain an IP address by DHCP and reserve
the address you want it to get from the scope at your DHCP server.

Stace.
 
<snip>

You could set the access point to obtain an IP address by DHCP and reserve
the address you want it to get from the scope at your DHCP server.
Click to expand...

Right. And if the concern about not having the WAP use a fixed address is not
being able to find the maintenance gui through a browser, there was reference
to a handy Windows widget that remembers the WAP's mac address and provides
its IP address when launched...

/daytripper (bottom line, though, that WAP's a piece o' crap)
 
I have some 1200 waps and these pass on dhcp info no probs.
Can you not set up a dhcp-helper address in the config to pass requests back
to the server ?
 
How to make your AP "pass" DHCP

I had the same problem...tried ip dhcp relay, smart-relay, pools, etc. (you need console access to configure DHCP settings, cannot access these settings from the HTTP interface)
Nothing seemed to work.
So I basically reset the device to defaults (step 2 below) and it worked fine with NO config changes
To fix:
1. Load the most recent IOS image from Cisco...I am a few revs back, using c1200-k9w7-tar.123-7.JA.tar
2. The Web interface did NOT erase the device, therefore I used the console method below:
***erase nvram as follows:
From the privileged EXEC mode, you can reset the access point/bridge configuration to factory default
values using the CLI by following these steps:
Step 1 Enter erase nvram: to erase all NVRAM files including the startup configuration.
Step 2 Enter Y when the following CLI message displays: Erasing the nvram filesystem will remove all
configuration files! Continue? [confirm].
Step 3 Enter reload when the following CLI message displays: Erase of nvram: complete. This command
reloads the operating system.
Step 4 Enter Y when the following CLI message displays: Proceed with reload? [confirm].
Caution Do not interrupt the boot process to avoid damaging the configuration file. Wait until the access
point/bridge Install Mode LED begins to blink green before continuing with CLI configuration changes.
You can also see the following CLI message when the load process has finished: Line protocol on
Interface Dot11Radio0, changed state to up.
Step 5 After the access point/bridge reboots, you can reconfigure the access point/bridge by using the
Web-browser interface or the CLI (refer to the Cisco IOS Software Configuration Guide for Cisco
Aironet Bridges or to the Cisco IOS Software Configuration Guide for Cisco Aironet Access Points).
The access point/bridge is configured with the factory default values including the IP address (set to
receive an IP address using DHCP). To obtain the unit’s new IP address, you can use the show interface
bvi1 CLI command. If the unit does not receive an IP address from a DHCP server, the access
point/bridge IP address is 10.0.0.1.
3. Your AP will then reboot and get its address from a DHCP server
4. Perform an IP Scan to find your AP, Angry IP will do this for you, http://www.angryziber.com/ipscan/
5. Configure via HTTP browser
6. Try connecting to your AP via wireless client...this tests your DHCP relay
7. It should work, you can now change your AP to static via HTTP browser
8. Ta Da
note, you should NOT have to configure any DHCP settings from the console, i.e. no pools, etc.

Hope this helps!
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