For the bored techies:problems running thu broadband router on Wimax

Hi Guys,
I was running thru wimax from one PC 100%. All email (outlook on Win2000) and web pages (IE 6.0) worked. I then purchased a Dlink router (DIR-100) as a cheap way to drive a small LAN to get a laptop to share the Internet (not the mail).This seemed to work perfectly until I noticed there was one web page I could not get to. It gave "cannot find server or DNS error" on the orignal desktop yet worked from the laptop. I can ping the page IP address and the domain name from the desktop and that works. I then noticed that the outgoing email from our account was not going thru. The “send/receive” takes a minute or so to clear . When it does, there are no errors and it looks like the SMTP server (smtp.saix.net) takes it, but the mail never gets to destination. Receive mail works 100%.
The strange part of this is if I go onto Outlook and do a “test account settings” from the email account admin. The mail is sent immediately (by Microsoft Outlook manager) and takes about 30 seconds before I receive it back from my ISP. I moved my PC back to direct on the Wimax and mail leaves immediately , reaches the destination and I receive it back within 30 seconds as with Microsoft Outlook manager.
The webpage also works 100% so the issue seems to be in the router. It is set for DHCP and NAT.
Any ideas would be welcome as I have spent hours on this without any progress, so I have given up now, will get a cup of coffee and wait for one of our experts on this forum to fix it for me

Check the DNS settings of the desktop (should be set to automatic). Maybe also do a ipconfig /flushdns. Is that Dlink a broadband router? In other works the PPP connection is now being made from the router?

Thanks for your response.
Both laptop and desktop have identical settings, ie all automatic settings and they both pick up the SAIX dns server addresses. Have tried flushing DNS and registering a number of times. No luck. The router is a broadband that now handles the PPPOE to my ISP instead of the PPPOE stack I had in the desktop. This is really the only change on the desktop except that it now gets an DHCP IP address from the router. Just wondering if it has something to do with NAT translation but it "should" work.. I can also tracert to the SMTP server with no issues.In fact when the mail goes there are no errors logged anywhere , it just goes into a big black hole..

Switch all dns to OpenDNS and see if that helps.

I had similar issues with the DLink - changed to a Linsys and the problems are gone. I never did find out what the problem was - now using a WRT 150N and it is great.

hope that helps

Hi Guys,
Many thanks for your suggestions.. OpenDNS made no difference. This weekend I will play with "port forwarding" and "DMZ" and see how that goes. Failing that I will have to look at alternatives.It has worked all week with the router bypassed so it looks like the problem is certainly in that litle box.
cheers

Check the MTU setting on the D-Link. Try reducing it to 1400 if it is around 1492. Should be easy enough to do. Also ping your ISP website e.g D:\ >ping -f -l 1492 smtp.saix.net

Pinging smtp.saix.net [196.25.240.94] with 1492 bytes of data:

Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.

this tells the ip routers not to DeFragment your packets (-l 1492 is the size of the packet you are sending) Reduce this packet size until you get >>
D:\>ping -f -l 1430 smtp.saix.net

Pinging smtp.saix.net [196.25.240.94] with 1430 bytes of data:

Reply from 196.25.240.94: bytes=1430 time=83ms TTL=124
Reply from 196.25.240.94: bytes=1430 time=103ms TTL=124
Reply from 196.25.240.94: bytes=1430 time=78ms TTL=124
Reply from 196.25.240.94: bytes=1430 time=101ms TTL=124

Ping statistics for 196.25.240.94:

This would be a good starting point to set MTU size in the D-Link, but probably a bit lower would be more reliable.
Let us know what happens !!!!

Thanks Hawkhunter, I thought SAIX was 1492... But.. having said that I will give it a whirl as this is probably the ONLY setting I haven't tried yet (even putting the PC in the DMZ didnt help).
I have sent a mail to Dlink support and wait to see what they have to say. Failing that, that box and I will part company and I will have a recommendation for anybody looking for a broadband router on Wimax.
cheers

it works! thank you, thank you ,well done to Hawkerhunter

Well done Mr Hawkerhunter.. I changed the MTU to 1430 and it worked immediately. Mail now goes out and the web pages I was having problems with ie "cannot find server or DNS error", also work. I will do some more testing but it looks like you have given this router a second chance. I must say I didn't think that would make that much difference
Many thanks again for all your help out there