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dhcp proxy option in controller

Hi,

While configuring a 5500 wireless controller, i came across this option of DHCP proxy under Advanced tab of Controller Option.

It asks for the dhcp option 82 remote id format & the dhcp timeout.

1. What is the significance of this & when do we use it?

2. Also, under each wlan ssid that we create, there is an option of dhcp address required under the advanced tab. Do we need to use this option, if we are defining a normal dhcp pool in our controller for that ssid.

Thanks in advance.

1 ACCEPTED SOLUTION

Accepted Solutions

dhcp proxy option in controller

DHCP proxy is needed if the WLC is the DHCP server for any WLAN.  Other than that, it's a hold over from the Airespace days, that let the WLC learn the IP address of a client.

In modern WLC deployments you don't need to have it enabled, so long as you have your ip helper configured at L3.

HTH,
Steve

-----------------------------------------
Please remember to rate useful posts, and mark questions as answered

HTH, Steve ------------------------------------------------------------------------------------------------ Please remember to rate useful posts, and mark questions as answered
3 REPLIES

dhcp proxy option in controller

DHCP proxy is needed if the WLC is the DHCP server for any WLAN.  Other than that, it's a hold over from the Airespace days, that let the WLC learn the IP address of a client.

In modern WLC deployments you don't need to have it enabled, so long as you have your ip helper configured at L3.

HTH,
Steve

-----------------------------------------
Please remember to rate useful posts, and mark questions as answered

HTH, Steve ------------------------------------------------------------------------------------------------ Please remember to rate useful posts, and mark questions as answered

Re: dhcp proxy option in controller

Option 82 is used so the dhcp agent (wlc in our case) to add moreinformation about itself to the dhcp request fromthe client before forwarding the Packet to the dhcp server

www.cisco.com/en/US/docs/ios/12_3t/12_3t4/feature/guide/gdhcpopt.html

For dhcp required, mark it if you want to prevent wlan users from using static ip addresses and force them to get an ip from dhcp only.

HTH

Amjad

Sent from Cisco Technical Support iPad App

Rating useful replies is more useful than saying "Thank you"
Cisco Employee

dhcp proxy option in controller

#dhcp proxy on WLC is much like a hack. and can also be used for external dhcp server as well.

#option 82 doesn't work if dhcp proxy is disabled on wlc.

#Enabling DHCP proxy is good as it hides the dhcp server ip over the air, it shows virtual ip of WLC as dhcp server.

#Also, it unicasts the dhcp handshake between WLC - External dhcp server & wireless client - WLC. If ASA firewall act as dhcp server that doesn't like this unicast where it needs to be turned off.

#dhcp required is not good for voice wlan.

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