I have spent literally dozens of hours trying to troubleshoot this.
The SETTING: I have redundant internet connections coming in from two different companies and I am trying to use the SA520 in "load balancing" mode. The primary connection is working just fine as long as it is the only one.
PROBLEM: The WAN connection on the 2nd ("optional") port does not allow most websites to be loaded, or if it does load, it can take literally minutes for the header image to load. (I can ping just fine, so maybe it isn't DNS?)
Here is the interesting thing, though: certain websites will work without problems! I can pull up most Google pages (including subpages, such as news & images) and Cisco.com just fine. But it refuses to load most any other website I would try, including MSN, Yahoo, etc.
TROUBLESHOOTING: Here is what I have tried:
-- Different browsers (IE & Chrome)
-- Different OS (Win 7 Pro, Win Server 2k3)
-- Different DNS servers (ISP, OpenDNS, 18.104.22.168)
All with the same results when using the 2nd WAN connection. It will sit forever "waiting for XYZ.com to respond". It's like it will allow a few KB of data through (it will resolve the page name at the top of the browser!), then it cuts it off for that site.
When plugging the modem straight into a laptop (bypassing the SA520W), all webpages work fine, with any of the 3 DNS servers. So I know I have a good connection to the web.
Also, I have switched the primary and secondary ISP connections (from dedicated to optional WAN port) and the SAME problem happens with the Optional WAN port, regardless of which ISP is plugged into it. They both work fine independently on the primary port.
Here is the CRAZY thing, though! When connected wirelessly through my iPhone (mobile Safari), I can pull up any page that I want, connected through the SA520W, using only the 2nd Port! So I am at a complete loss!
Any suggestions / ideas / help? It would be much appreciated. Thanks!
(Original Post: 8/29/10. Edited by: metachimp on 9/12/10)