said by birdfeedr :

DMZ does not appear to be a straight pass-through.

said by cdru :

The DMZ is just a catch all for incoming connections. Instead of having to explicitly forward a port or range of ports to a particular host, you can put a machine in the DMZ and have any connections that don't match a particular port forwarding rule or existing connection get forwarded to that machine. The router still has to maintain the NAT mapping, thus your NAT table will fill up.

My guess is the difference between getting 25 servers and 159 servers wasn't the fact that you were using the DMZ, but rather what initial peers you were connecting to and the NAT table utilization prior to launching Steam. To get a more accurate gauge, I would reset the actiontec to ensure the NAT table was empty (or as reasonably empty as possible) as well as delete any cached data from within the application. Then repeat the process several times to get an average.

said by birdfeedr :

There are vastly more UDP connections than TCP. Would this be a factor in the behavior seen so far?

said by aaronwt :

1. First it showed 3184, then 3212, then 3418, and then 3438 servers.

2. I was able to log into my ActionTec like normal during all of this, it popped up quick as usual. Nothing is in the ActionTec log except the hourly IP renewal which is normal.

3. I was also able to get into the Dlink router with no problems each time. That log does show bunch of entries.

4. But the whole time this was going on the only thing I noticed was when I refreshed the DSLR page instead of popping up in a split second it would take 5 to 10 seconds.

5. Other sites I tried would either do the same thing or pop up right away. And then of course as soon as I stopped the server refresh all pages would pop up in a split second.

6. What should I look for specifically in the Dlink logs?
From a user stand point it just slowed down loading a few sites. My three VUDU boxes were still uploading during all of this at around 300kbs for each one which is normal, and my squeeze boxes didn't have any problem streaming music during all of this either. And of course my internal network was fine. My transfers from my TiVos were still fine during this to my TiVo Server.

said by birdfeedr :

@ aaronwt: I will try to establish additional benchmark tests to explore the NAT table problem. My Actiontec is not currently running the new 10.11.3 firmware. Is yours?

I'm just trying to find the differences between your setup and mine to explain why you have different results. Perhaps internal perormace of the DGL is also a factor.

said by birdfeedr :

Very interesting. The 10.11.3 firmware no longer logs the "NAT error connection pool is full" error message.

Under the new firmware with DLink connected LAN-to-LAN, the Steam application exhibits the same behavior already reported. It seems it took longer to recover once I canceled the Steam Server Refresh.

[edit to add]Confirmed. Same behavior when DLink is LAN-to-LAN in the DMZ. Reverted to 10.7, and error messages reappear. No change in Log settings from one firmware to the next.

said by aaronwt :

I connect my DLINK WAN port to the Actiontec LAN port. Would that create any differences?