D-Link DCM-604 Series User Manual page 24

DCM-604 Series EMTA Embedded Multimedia Terminal Adaptor
User's Manual
To reset the router, locate the reset button (hole) on the rear panel of the unit. With the
router powered on, use a paperclip to hold the button down for 10 seconds. Release the
button and the router will go through its reboot process. Wait about 30 seconds to access
the router. The default IP address is 192.168.0.1. When logging in, the username is
"admin" and the password is "password".
3. Why can't I connect to certain sites or send and receive emails when connecting
through my router?
If you are having a problem sending or receiving email, or connecting to secure sites such
as eBay, banking sites, and Hotmail, we suggest lowering the MTU in increments of ten
(Ex. 1492, 1482, 1472, etc).
Note: AOL DSL+ users must use MTU of 1400.
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.
• Click on Start and then click Run.
• Windows® 95, 98, and Me users type in command (Windows® NT, 2000, and XP users
type in cmd) and press Enter (or click OK).
• Once the window opens, you'll need to do a special ping. Use the following syntax: ping
[url] [-f] [-l] [MTU value]
Example: ping yahoo.com -f -l 1472
You should 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 (1452+28=1480).
Once you find your MTU, you can now configure your router with the proper MTU size.
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