Mtu Concepts - NETGEAR Nighthawk D7000 User Manual

Nighthawk AC1900 WiFi VDSL/ADSL Modem Router Model D7000

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 9. Common MTU sizes
MTU
1500
1492
1472
1468
1460
1458
Application
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.
Used in PPPoE environments.
Maximum size to use for pinging. (Larger packets are fragmented.)
Used in some DHCP environments.
Usable by AOL if you do not send or receive large email attachments, for example.
Used in PPPoA environments.
Manage the Internet Settings Manually
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