D-Link DIR-605L User Manual page 77

Section 6 - Troubleshooting
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, let's 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.
To change the MTU rate on your router follow the steps below:
• Open your browser, enter the IP address of your router (the default is 192.168.0.1) and click OK.
• Enter your username and password. Click OK to enter the web configuration page for the device.
• Click on Setup then click Manual Setup.
• To change the MTU enter the number in the MTU field and click the Save Settings button to save your settings.
• Test your e-mail. If changing the MTU does not resolve the problem, continue changing the MTU in increments
of ten.
D-Link DIR-605L User Manual 73