 | Moderator with 58,613 posts. | | Join Date: Mar 2005 Location: Ottawa, IL | |
The following was obviously written for a router, but it works if you just have PC connected directly to your DSL modem. I don't know offhand how you set the MTU (if it needs to be changed) in the case of just PC and modem. Most times, I think, the MTU should be 1500 or 1492.
On your router there should be an option for mtu. use this formula.
To find the proper MTU Size, you'll have to do a special ping of the
destination you're trying to go to. A destination could be another
computer, or a URL.
1. Click on the Start button, then select the Run option.
2. In the "Open" field type in command (If you're using Windows
2K/NT/XP use CMD instead)
3. Once the window opens, you'll need to do a special ping. It
should be formatted:
ping [url] [-f] [-l] [MTU value] [Enter] an example would be:
ping yahoo.com -f -l 1472 <result = fragmented packet>
ping yahoo.com -f -l 1462 <result = fragmented packet>
ping yahoo.com -f -l 1452 <result = reply>
You should always start at 1472 and work your way down by 10 each
time. Once you get a reply, go up by 2 until you get a fragmented
packet. Take that value and add 28 to the value to account for the
various TCP/IP headers. For example, lets say that 1452 was the
proper value, the actual MTU size would be 1480, which is the optimum
for the network we're working with.
4. Once you've found the optimum MTU size open up your browser,
usually Internet Explorer, which is located on your desktop (Or on
the Start menu in Windows XP)
Enter the MTU you get from this into the MTU settings on the router. Or on the modem. |
