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SA520W DNS help required


Let me start by stating that I am very weak in router-speak so please step-by-step.

SA 520W with latest firmware.  Static IP from Comcast.  No DHCP at SA520.  DHCP provided by SBS 2003 server.  DNS points to Comcast DNS.  My problem is only on the wireless.side.

Wireless devices can all connect well. All report a good connection.  Wireless devices are also receiving a DHCP provided by the SBS 2003 server (in the 10.0.0.x range)  But wireless devices do not seem to be rsolving DNS.  They cannot connect to the Internet.

Wireless computers can be set to manual DNS addresses (Comcast DNS) and then they can resolve and connect to the Intenet.  Wired computers on the intenal network the same.  But wireless devices such as smart phones have no manual DNS setting and so will not connect to the Internet.

The SA520W is otherwise in default configuration.  Only the one WAN, no VLANS, 

The goofy tthing is, we ran this same SA520W in test mode at our shop before deployment and it worked perfectly.  All wireless devices connected perfectly.  We may have misconfigured something but what??  The only difference we can see is the test network was on a 192.168.16.x .  Could this matter?

Any guidance or suggestions are most welcome.

Thank you!

4 Replies 4

Ismael Arroyo

Hi jrengel

So to my understanding all wireless clients are able to resolve by name, except the wireless smart phones. Were this phones able to resolve by name while you were running a test in your shop?

Hello Ismael:

Yes, in our test rnvironment...  Also set up on a windows SBS network, and with a static comcast ip using the same comcast dns entries and no DHCP on the SA520W.  The only difference UNLESS we misconfigured the device when we reinstalled, is the SBS ip range which was the 192.168.16.x.

The wireless smart phones worked as expected in the test environment.  Both Android and iPhone devices worked in the test environment.

Is there anybody out there that can help us with this??  It is really becoming a major issue with our customer.


Kremena Ivanova
Cisco Employee
Cisco Employee


In the LAN configuration menu you have the option DNS proxy ( Enable DNS Proxy: Check this box to allow the security appliance to act as a proxy for all DNS requests and to communicate with the DNS servers of the

ISP. When this feature is disabled, all DHCP clients receive the DNS IP addresses of the ISP. )

Can you share if this option is enabled or disabled



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