Netgear Dgnd4000 N750 Wireless Dual Band Gigabit Adsl2 Plus Modem Router User Manual

							NETGEAR genie ADVANCED Home 
51  N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000
•NAT Filtering. Network Address Translation (NAT) determines how the wireless 
modem router processes inbound traffic. Secured NAT provides a secured firewall to 
protect the computers on the LAN from attacks from the Internet, but might prevent 
some Internet games, point-to-point applications, or multimedia applications from 
functioning. Open NAT provides a much less secured firewall, but allows almost all 
Internet applications to function. 
-Disable SIP ALG. Some VoIP applications do not work well with the SIP ALG. 
Enabling this option to turn off the SIP ALG might help your VoIP devices to 
create or accept a call through the router.
Default DMZ Server
The default DMZ server feature is helpful when you are using some online games and 
videoconferencing applications that are incompatible with Network Address Translation 
(NAT). The wireless modem router is programmed to recognize some of these applications 
and to work correctly with them, but there are other applications that might not function well. 
In some cases, one local computer can run the application correctly if that computer’s IP 
address is entered as the default DMZ server.
WARNING:
DMZ servers pose a security risk. A computer designated as the 
default DMZ server loses much of the protection of the firewall and 
is exposed to exploits from the Internet. If compromised, the DMZ 
server computer can be used to attack other computers on your 
network.
Incoming traffic from the Internet is discarded by the wireless modem router unless the traffic 
is a response to one of your local computers or a service that you have configured in the Port 
Forwarding/Port Triggering screen. Instead of discarding this traffic, you can forward it to one 
computer on your network. This computer is called the default DMZ server.
To set up a default DMZ server: 
1. On the WAN Setup screen, select the Default DMZ Server check box.
2. Type the IP address.
3. Click Apply.
Change 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 any device in the data path has a lower MTU 
setting than the other devices, the data packets have to be split or “fragmented” to 
accommodate the device with the smallest MTU.  
						

							NETGEAR genie ADVANCED Home 52
N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000 
The best MTU setting for NETGEAR equipment is often just the default val\
ue, and changing 
the value might fix one problem but cause another. Leave the MTU unchanged unless one of 
these situations occurs:
• Y
ou have problems connecting to your ISP or other Internet service, and t\
he 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\
- Y
ahoo email
- MSN portal
- 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 h\
ave 
connectivity or performance problems.
Note: An incorrect MTU setting can cause Internet communication problems 
such as the inability 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 11.  Common MTU sizes   
MTUApplication
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 wir\
eless 
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 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.
 
To change the MTU size:
1. Select  ADV
 ANCED > Setup > WAN Setup.  
						

							NETGEAR genie ADVANCED Home 53
 N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000
2. 
In the MTU Size field, enter a new size from 64 through 1500.
3.  Click  Apply to save the settings.
LAN Setup
The LAN Setup screen allows configuration of LAN IP services such as Dyn\
amic Host 
Configuration Protocol (DHCP) and Routing Information Protocol (RIP)\
.
The wireless modem router is shipped preconfigured to use private IP add\
resses on the LAN  side and to act as a DHCP server
 . The wireless modem router’s default LAN IP configuration 
is:
• LAN IP address. 192.168.0.1
• Subnet mask.  255.255.255.0
These addresses are part of the designated private address range for use\
 in private networks  and should be suitable for most applications. If your network requires a\
 dif
 ferent IP 
addressing scheme, make those changes in the LAN Setup screen.
To change the LAN settings:
Note: If you change the LAN IP address of the wireless modem router while 
connected through the browser, you are disconnected. You have to 
open a new connection to the new IP address and log in again.
1.  Select  ADV
 ANCED > Setup > LAN Setup. 
2. Enter the settings that you want to customize.  
						

							NETGEAR genie ADVANCED Home 
54 N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000 
These settings are described in the following section, LAN Setup Screen Settings.
3. Click Apply to save your changes.
LAN Setup Screen Settings
LAN TCP/IP Setup
•IP Address. The LAN IP address of the wireless modem router.
•IP Subnet Mask. The LAN subnet mask of the wireless modem router. Combined with 
the IP address, the IP subnet mask allows a device to know which other addresses are 
local to it, and which have to be reached through a gateway or wireless modem router.
•RIP Direction. Router Information Protocol (RIP) allows a router to exchange routing 
information with other routers. This setting controls how the router sends and receives 
RIP packets. Both is the default setting. With the Both or Out Only setting, the router 
broadcasts its routing table periodically. With the Both or In Only setting, the router 
incorporates the RIP information that it receives.
•RIP Version. This setting controls the format and the broadcasting method of the RIP 
packets that the wireless modem router sends. It recognizes both formats when 
receiving. By default, the RIP function is disabled. 
-RIP-1 is universally supported. It is adequate for most networks, unless you have an 
unusual network setup. 
-RIP-2 carries more information. Both RIP-2B and RIP-2M send the routing data in 
RIP-2 format. RIP-2B uses subnet broadcasting. RIP-2M uses multicasting.
Use Router as a DHCP Server 
This check box is selected so that the wireless modem router functions as a Dynamic Host 
Configuration Protocol (DHCP) server. 
•Starting IP Address. Specify the start of the range for the pool of IP addresses in the 
same subnet as the wireless modem router.
•Ending IP Address. Specify the end of the range for the pool of IP addresses in the 
same subnet as the wireless modem router.
Address Reservation
When you specify a reserved IP address for a computer on the LAN, that computer receives 
the same IP address each time it accesses the wireless modem router’s DHCP server. 
Assign reserved IP addresses to servers that require permanent IP settings. 
Use the Wireless Modem Router as a DHCP Server
By default, the wireless modem router functions as a DHCP server, allowing it to assign IP, 
DNS server, and default gateway addresses to all computers connected to the wireless 
modem router’s LAN. The assigned default gateway address is the LAN address of the 
wireless modem router. The wireless modem router assigns IP addresses to the attached  
						

							NETGEAR genie ADVANCED Home 55
 N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000
computers from a pool of addresses specified in this screen. Each pool a\
ddress is tested 
before it is assigned to avoid duplicate addresses on the LAN. For most \
applications, the 
default DHCP and TCP/IP settings of the wireless modem router are satisfactory. 
You can specify the pool of IP addresses to be assigned by setting the st\
arting IP address  and ending IP address. 
 These addresses should be part of the same IP address subnet as 
the wireless modem router’s LAN IP address. Using the default addressing scheme, you 
should define a range between 192.168.0.2 and 192.168.0.254, although yo\
u might want to 
save part of the range for devices with fixed addresses.
The wireless modem router delivers the following parameters to any LAN d\
evice that  requests DHCP:
• An IP address from the range you have defined
• Subnet mask
• Gateway IP address (the wireless modem router’
 s LAN IP address)
• Primary DNS server (if you entered a primary DNS address in the Interne\
t Basic Settings 
screen; otherwise, the wireless modem router’

s LAN IP address)
• Secondary DNS server (if you entered a secondary DNS address in the Int\
ernet Basic 
Settings screen)
To use another device on your network as the DHCP server, or to manually configure the  network settings of all of your computers, clear the Use Router as DHCP Server  check box 
and click  Apply. Otherwise, leave this check box selected. If this service is not enabl\
ed and 
no other DHCP server is available on your network, you need to set your \
computers’ IP 
addresses manually or they are not able to access the wireless modem rou\
ter.
Address Reservation
When you specify a reserved IP address for a computer on the LAN, that c\
omputer always 
receives the same IP address each time it accesses the wireless modem ro\
uter’s DHCP 
server. Reserved IP addresses should be assigned to computers or servers that \
require 
permanent IP settings. 
To reserve an IP address: 
1.  In the 
Address Reservation section of the screen, click the  Add button. 
2. In the IP Address field, type the IP address to assign to the computer or server. (Choose an 
IP address from the wireless modem router’s LAN subnet, such as 192.168.0.x.) 
3.  T
ype the MAC address of the computer or server. 
						

							NETGEAR genie ADVANCED Home 56
N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000 
Tip:
If the computer is already on your network, you can copy its MAC 
address from the Attached Devices screen and paste it here.
4.  Click  Apply  to enter the reserved address into the table. 
The reserved address is not assigned until the next time the computer co\
ntacts the  wireless modem router’
 s DHCP server. Reboot the computer or access its IP 
configuration and force a DHCP release and renew.
To edit or delete a reserved address entry, select the radio button next to the reserved  address you want to edit or delete. 
 Then click Edit or Delete.
Quality of Service Setup
Quality of Service (QoS) is an advanced feature that can be used to pr\
ioritize some types of 
traffic ahead of others. The N750 Modem Router can provide QoS prioritization over the 
wireless link and on the Internet connection. To configure QoS, use the QoS Setup screen. 
Select  ADV
 ANCED > Setup > QoS Setup. 
Enable WMM QoS for Wireless Multimedia Applications
The N750 Modem Router supports Wi-Fi Multimedia Quality of Service (WMM\
 QoS) to 
prioritize wireless voice and video traffic over the wireless link. WMM QoS provides 
prioritization of wireless data packets from different applications based on four access 
categories: voice, video, best effort, and background. For an application to receive the 
benefits of WMM QoS, both it and the client running that application hav\
e to have WMM 
enabled. Legacy applications that do not support WMM and applications th\
at do not require 
QoS are assigned to the best effort category, which receives a lower priority than voice and 
video.  
						

							NETGEAR genie ADVANCED Home 57
 N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000
WMM QoS is enabled by default. You can disable it in the QoS Setup screen by clearing the 
Enable WMM check box and clicking 
Apply.
Set Up QoS for Internet Access
You can give prioritized Internet access to the following types of traffic:
• Specific applications
• Specific online games
• Individual Ethernet LAN ports of the wireless modem router
• A specific device by MAC address
To specify prioritization of traffic, you have to create a policy for the type of traffic and add the  policy to the QoS Policy table in the QoS Setup screen. For convenience,\
 the QoS Policy 
table lists many common applications and online games that can benefit f\
rom QoS handling.
QoS for Applications and Online Gaming
To create a QoS policy for applications and online games:
1.  In the QoS Setup screen, select the T
 urn Internet Access QoS On check box.
2.  Click the  Setup QoS rule  button to see the existing priority rules. 
a. Edit or delete a rule by selecting its radio button and clicking either \
the  Edit or Delete 
button. 
b.  Delete all of the rules by clicking the  Delete All button.
3. To add a priority rule, scroll down to the bottom of the QoS Setup screen\
 and click  Add 
Priority Rule.  
						

							NETGEAR genie ADVANCED Home 58
N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000 
4. 
In the QoS Policy for field, type the name of the application or game.
5.  In the Priority Category list, select either  Applications or Online Gaming. 
In either case, a list of applications or games displays in the Applications list.
6.  In the 
Applications list, you can select an existing item, or you can scroll an\
d select  Add a 
New Application or  Add a New Game, as applicable. 
a. When you add a new entry
 , the QoS - Priority Rules screen expands as shown: 
b. In the QoS Policy for field, enter a descriptive name for the new applic\
ation or game.
c.  In the Connection 
 Type list, select either  TCP, UDP, or both (TCP/UDP), and specify 
the port number or range of port numbers used by the application or game\
.
7.  From the Priority list, select the priority that this traf
 fic should receive relative to other 
applications and traffic when accessing the Internet. The options are Low, Normal, High, and 
Highest.
8.  Click  Apply  to save this rule to the QoS Policy list and return to the QoS Setup sc\
reen. 
						

							NETGEAR genie ADVANCED Home 59
 N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000
QoS for a Wireless Modem Router LAN Port
To create a QoS policy for a device connected to one of the wireless mode\
m router’s 
LAN ports:
1. 
Select  ADV
 ANCED > Setup > QoS Setup to display the QoS Setup screen. Select the 
Turn Internet Access QoS On  check box.
2.  Click the  Setup QoS Rule button.
3.  Click the  Add Priority Rule button.
4.  From the Priority Category list, select  Ethernet LAN Port. 
5. From the LAN port list, select the LAN port that has a QoS policy.
6.  From the Priority list, select the priority that this port’
 s traffic should receive relative to other 
applications and traffic when accessing the Internet. The options are Low, Normal, High, and 
Highest.
7.  Click  Apply to save this rule to the QoS Policy list and return to the QoS Setup sc\
reen.
8.  In the QoS Setup screen, click  Apply.
QoS for a MAC Address
To create a QoS policy for traffic from a specific MAC address:
1. Select  ADV
 ANCED > Setup > QoS Setup, and click the Setup QoS Rule  button. The 
QoS Setup screen displays.
2.  Click  Add Priority Rule . 
3.  From the Priority Category list, select  MAC Address. 
4. From the Priority list, select the priority that this device’s traffic should receive relative to 
other applications and traffic when accessing the Internet. The options are Low, Normal, 
High, and Highest. Click  Add to add this rule to MAC Device List.
5.  Click  Apply to save this rule to the QoS Policy list and return to the QoS Setup sc\
reen.
6.  In the QoS Setup screen, select the  T
 urn Internet Access QoS On check box.
7.  Click  Apply . 
						

							NETGEAR genie ADVANCED Home 
60 N750 Wireless Dual Band Gigabit ADSL Modem Router DGND4000 
Edit or Delete an Existing QoS Policy
To edit or delete a QoS policy:
1. Select ADVANCED > QoS Setup to display the QoS Setup screen.
2. Select the radio button next to the QoS policy to be edited or deleted, and do one of the 
following:
•Click Delete to remove the QoS policy.
•Click Edit to edit the QoS policy. Follow the instructions in the preceding sections to 
change the policy settings.
3. Click Apply in the QoS Setup screen to save your changes.