Manage The Mtu Size; Mtu Concepts - NETGEAR D6100 User Manual

AC1200 WiFi DSL Modem Router—Essentials Edition Model D6100

Manage the MTU Size

The maximum transmission unit (MTU) is the largest data packet a network device transmits.

MTU Concepts

When one network device communicates across the Internet with another, the data packets
travel through many devices along the way. If a device in the data path uses a lower MTU
setting than the other devices, the data packets must be split or "fragmented" to
accommodate the device with the smallest MTU.
The best MTU setting for NETGEAR equipment is often the default value. In some situations,
changing the value fixes one problem but causes another.
Leave the MTU unchanged unless one of these situations occurs:
• You experience problems connecting to your ISP or other Internet service, and the
technical support of either the ISP or NETGEAR recommends changing the MTU setting.
These 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
- America Online's DSL service
• You use VPN and experience severe performance problems.
• You used a program to optimize MTU for performance reasons and now you are
experiencing 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. The following table describes common MTU sizes and
applications.
Table 3. Common MTU sizes
MTU Application
1500 The largest Ethernet packet size. This setting is typical for connections that do not use PPPoE
or VPN and is the default value for NETGEAR modem 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 do not send or receive large email attachments, for example.
1436 Used in PPTP environments or with VPN.
1400 Maximum size for AOL DSL.
Manage the Internet Settings Manually
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