Owner's Manual

NETGEAR genie Advanced Home
44
N300 Wireless ADSL2+ Modem Router DGN2200v3
The best MTU setting for NETGEAR equipment is often just 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:
• Y
ou have 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 web
site that does not open, or displays only part of a web page
- Y
ahoo email
- MSN port
al
- America Online’
s DSL service
• Y
ou use VPN and have severe performance problems.
• Y
ou used a program to optimize MTU for performance reasons, and now you have
connectivity or performance problems.
Note: An incorrect MTU setting can cause Internet communication
problems. For instance, you might not be able to access certain
websites, frames within websites, secure login pages, or FTP or
POP servers.
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 2. Common MTU Sizes
MTU Application
1500 The largest Ethernet packet size and the default value. This setting is typical for
con
nections 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 have large emai
l 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.