If you can access some, but not all websites or parts of some websites, experience FTP problems and/or cannot send and/or receive email, it may be caused by your MTU (maximum transmission Unit) size being set too high. Reducing the Maximum MTU size setting on the PC might correct this problem.
To determine the maximum MTU size for your Windows PC use the following procedure:•Open a Command or "DOS" Window.
•Ping a known "pingable" address with the command: ping -f -l 1500 somesite.com
•If the ping fails with the message "packet needs to be fragmented but DF set", keep trying the ping command but lower the packet size (1490, 1480, etc.) each time until you find a size that is successful.
Add 28 more to this (since you specified ping packet size, not including IP/ICMP header of 28 bytes) And this is your MaxMTU.
•Set the MaxMTU registry key on the PC to the successful packet size + 28. You can edit the registry manually or you can use a program such as DrTCP that will help you change the setting.
•Reboot the PC.
•Test the changes by trying to access a problem website or send/receive email.
Normal operation. You cannot access your server on the same LAN by using it's Domain Name (FQDN) or Public IP Address as loopback is completely disabled in quite a few SoHo Routers. It's a feature found in some, but not all Routers (it used be only in units starting at $600.00 and up until a few years ago). There is nothing you can do to enable loopback either. Sorry.
However, there are 3 work-a-rounds:
1) You can use the server's Private LAN IP to access it. 2) You can use a web proxy to access it (»www.guardster.com) by FQDN. 3) You can add an entry into your HOSTS file that shows your server domain name linked to the Private LAN IP.
Notation from the above page: If you do not find a kernel that matches your part number call (877) 820-0005 for assistance. Note: Using the wrong kernel can render your equipment useless and is not covered under warranty!
Siemens Subscriber Networks, Inc., A Siemens Company Hardware Extended Warranty Registration
Thank you for purchasing Siemens Subscriber Networks products. Our extended warranty program has concluded. Please see extended warranty card for conclusion details. SpeedStream products included in the extended warranty program were discontinued in June 2003. Henceforth the extended warranty program expired June 2004.
Products are covered by a standard one year warranty. Please maintain purchase documentation, as this will be needed for any warranty claims. Thank you.
Note: If you don't get a response during the ping test, you have another issue that needs to be diagnosed if you actually have a Router version of a SpeedStream Modem (not all SpeedStream Modems are Routers and not all ISP provided SpeedStream use 192.168.254.254 as the Gateway IP). If you have a 5100, 5200, 4100, or 4200 then not all of those were sold as Routers either. See Accessing the Web Management Interface on my SpeedStream 5100 or 5200 which steps also apply to the 4100 and the 4200 versions.