If you do not specify an ID here, the modem router generates one automatically from its MAC address.
10. Select the IPv6 filtering mode:
•Secured. In secured mode, which is the default mode, the modem router inspects both TCP and UDP packets.
•Open. In open mode, the modem router inspects UDP packets only.
11. Click the Apply button.
Your settings are saved.
Manage the MTU Size
The maximum transmission unit (MTU) is the largest data packet a network device transmits.
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 maximum transmission unit (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
•A secure website that does not open or displays only part of a web page
•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
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.
Manage the Internet Settings Manually
Nighthawk X4S AC2600 WiFi VDSL/ADSL Modem Router Model D7800