Tenda F1200 User Manual page 32

A. You have problems connecting to your ISP or other Internet service, and the
technical support of either your ISP or Tenda suggests changing the MTU value.
Below web-based applications might require an MTU change:
 A secure website that does not open, or displays only part of a web
page
 Yahoo email

MSN portal
B. You use VPN and encounter serious performance problems.
C. You used a program to optimize MTU for performance reasons, and now you
have connectivity or performance problems.
If you suspect an MTU problem, try changing the MTU to 1400. If this does not
help, gradually reduce the MTU from the maximum value of 1500 until the
problem disappears.
The common MTU sizes and applications are listed in the table below.
MTU
1500
1492
1472
1468
1436
Note -------------------------------------------------------------------------------------
A wrong/improper MTU value may cause Internet communication problems. For
example, you may be unable to access certain websites, frames within websites,
secure login pages, or FTP or POP servers.
-----------------------------------------------------------------------------------------------
Application
Typical for connections that do not use PPPoE or VPN.
Used in PPPoE environments.
Maximum size to use for pinging. (Larger packets are
fragmented.)
Used in some DHCP environments.
Used in PPTP environments or with VPN.
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