NETGEAR RangeMax™ NEXT Wireless Router WNR854T User Manual
Fine-Tuning Your Network 6-15
v1.1, January 2007
• You have problems connecting to your ISP, or other Internet service, and either the technical
support of the ISP or of NETGEAR recommends changing MTU. These may require an MTU
change:
— A secure Web site that won't open, or only displays part of a Web page
— Yahoo email
—MSN
— America Online's DSL service
• You use VPN and have severe performance problems.
• You used a program to optimize MTU for performance reasons, and now you have
connectivity or performance problems..
If you suspect an MTU problem, a common solution is to change the MTU to 1400. If you are
willing to experiment, you can gradually reduce the MTU from the maximum value of 1500 until
the problem goes away. Table 6- 1 describes common MTU sizes and applications.
To change the MTU size:
1. In the Advanced section of the main menu, click WAN Setup.
2. Under MTU Size, enter a new size between 64 and 1500.
Note: An incorrect MTU setting can cause Internet communication problems such as the
inability to access certain Web sites, frames within Web sites, secure login pages,
FTP or POP servers.
Table6-1. Common MTU Sizes
MTU Application
1500 The largest Ethernet packet size and the default value. This is the typical setting for non-
PPPoE, non-VPN connections, and is the default value for NETGEAR routers, adapters,
and switches.
1492 Used in PPPoE environments.
1472 Maximum size to use for pinging. (Larger packets are fragmented.)
1468 Used in some DHCP environments.
1460 Usable by AOL if you don't have large email attachments, for example.
1436 Used in PPTP environments or with VPN.
1400 Maximum size for AOL DSL.
576 Typical value to connect to dial-up ISPs.