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virtual interface ip of Wireless controller

Hi,

In our wireless controller, there is a virtual interface having ip 192.168.100.1.

when tracing the packets, we saw this ip being reflected in sniffer as dhcp server address instead of original dhcp server ip.

The controller interfaces of ssid have original dhcp server ip ( 172.16.31.2 ) mentioned in them, this is where clients get there ip from.

In this case, why does virtual interface ip (192.168.100.1) is seen as dhcp server in sniffer traces instead of original dhcp server 172.16.31.2

Appreciate all inputs to help me understand this.

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Hall of Fame Super Silver

Re: virtual interface ip of Wireless controller

If you have dhcp proxy enabled in the WLC, which is default, the WLC will proxy dhcp and it uses the virtual IP address. If you look at a client that is connected to the wireless and on a windows machine you look at the ipconfig /all, you will also see that the dhcp server is the virtual IP address if the WLC. Dhcp proxy can be disabled as long as you dint have the WLC being used as the dhcp server, or else it it's required to have dhcp proxy enabled.

Virtual IP is also used for mobility and guest portal page.

Sent from Cisco Technical Support iPhone App

-Scott
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2 REPLIES
Hall of Fame Super Silver

Re: virtual interface ip of Wireless controller

If you have dhcp proxy enabled in the WLC, which is default, the WLC will proxy dhcp and it uses the virtual IP address. If you look at a client that is connected to the wireless and on a windows machine you look at the ipconfig /all, you will also see that the dhcp server is the virtual IP address if the WLC. Dhcp proxy can be disabled as long as you dint have the WLC being used as the dhcp server, or else it it's required to have dhcp proxy enabled.

Virtual IP is also used for mobility and guest portal page.

Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***
Hall of Fame Super Silver

Re: virtual interface ip of Wireless controller

Here is a link that can help:

http://www.cisco.com/en/US/docs/wireless/controller/7.4/configuration/guides/consolidated/b_cg74_CONSOLIDATED_chapter_011101.html

Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***
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