Netgear Dm200 Broadband High Speed Dsl Modem User Manual

							If you do not specify an ID here, the modem generates one automatically from its MAC address.
9. Clic
k the Apply button.
Y

our settings are saved.
Use Auto Config for an IPv6 Internet Connection
To set up an IPv6 Internet connection through autoconfiguration: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter 
http://www.routerlogin.net.
A login window opens.
3. Enter the 
modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays.
4. Select ADVANCED > Advanced Setup > IPv6.
The Basic Settings page displa

ys.
5. From the 
Internet Connection Type menu, select Auto Config. The 
modem automatically detects the information in the following fields:
• Router’
s IPv6 Address on WAN. This field shows the IPv6 address that is acquired for the modem’s
WAN (or Internet) interface. The number after the slash (/) is the length of the prefix, which is also Manage the Internet Settings Manually
51
Broadband High-Speed DSL Modem Model DM200 
						

							indicated by the underline (_) under the IPv6 address. If no address is acquired, the field displays
Not Available.
• Router’s IPv6 Address on LAN. This field shows the IPv6 address that is acquired for the modem’s
LAN interface. The number after the slash (/) is the length of the prefix, which is also i\
ndicated by
the underline (_) under the IPv6 address. If no address is acquired, the field displays Not Available.
6. (Optional) In the DHCP User Class (If Required) field, enter a host name.
Most people can lea
ve this field blank, but if your ISP gave you a specific host name, enter it here.
7. (Optional) In the DHCP Domain Name (If Required) field, enter a domain name.
Y

ou can type the domain name of your IPv6 ISP. Do not enter the domain name for the IPv4 ISP here.
For example, if your ISP’s mail server is mail.xxx.yyy.zzz, type xxx.yyy.zzz as the domain name. If your
ISP provided a domain name, type it in this field.
8. Select an IP Address Assignment radio button:
•Use DHCP Server
. This method passes more information to LAN devices but some IPv6 systems
might not support the DHCv6 client function.
• Auto Config. This is the default setting.
This setting specifies ho
 w the modem
 assigns IPv6 addresses to the devices on your home network
(the LAN).
9. (Optional) Select the 
Use This Interface ID check box and specify the interface ID to be used for the
IPv6 address of the 
modem’s LAN interface.
If you do not specify an ID here, the 
modem generates one automatically from its MAC address.
10. Clic
k the Apply button.
Y

our settings are saved.
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 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. Manage the Internet Settings Manually
52
Broadband High-Speed DSL Modem Model DM200 
						

							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
• 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 2. Common MTU sizes Application
MTU
The largest Ethernet packet size. This setting is typical for connections that
do not use PPPoE or VPN and is the default value for the modem.
1500
Used in PPP

oE environments.
1492
Maximum size to use for pinging. (Larger packets are fragmented.)
1472
Used in some DHCP environments.
1468
Usable by AOL if you do not send or receive large email attachments, for
example.
1460
Used in PPPoA environments.
1458
Used in PPTP environments or with VPN.
1436 Manage the Internet Settings Manually
53
Broadband High-Speed DSL Modem Model DM200 
						

							Change the MTU Size
WARNING:An incorrect MTU setting can cause Internet communication problems. For
example, you might not be able to access certain websites, frames within
websites, secure login pages, or FTP or POP servers. Change the MTU only
if you are sure that it is necessary for your ISP connection. To change the MTU size:
1.
Launch a web browser from a computer that is connected to the network.
2. Enter http://www.routerlogin.net.
A login window opens.
3. Enter the modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays.
4. Select 
ADVANCED > Setup > WAN Setup.
The 
WAN Setup page displays.
5. In the 
MTU Size field, enter a value from 616 to 1500.
The nor
mal MTU (maximum transmit unit) value for most Ethernet networks is 1500 bytes or 1492 bytes
for PPPoE connections.
6. Click the Apply button.
Y

our settings are saved. Manage the Internet Settings Manually
54
Broadband High-Speed DSL Modem Model DM200 
						

							4
Manage the WAN and LAN Network
Settings
This chapter describes how you can manage the WAN and LAN network settings of the modem.
The chapter includes the f
ollowing sections:
• Manage the WAN Security Settings
 on page 56
• Manage NA
T Filtering
 on page 56
• Manage the SIP Application-Le
vel Gateway on page 
57
• Manage IGMP Proxying on page 57
• Manage the Modem’

s LAN IP Address Settings on page 58
• Manage the Router Inf

ormation Protocol Settings
 on page 59
• Manage Reser
ved LAN IP Addresses
 on page 60
• Manage the DHCP Ser
ver Address Pool
 on page 62
• Disab
le the Built-In DHCP Server
 on page 63
• Change the Modem’s Device Name
 on page 64
• Set Up and Manage Custom Static Routes
 on page 65 55 
						

							Manage the WAN Security Settings
The WAN security settings include port scan protection and denial of service (DoS) protection, which can
protect your LAN against attacks such as Syn flood, Smurf Attack, Ping of Death, and many others. By
default, DoS protection is enabled and a port scan is rejected.
You can also enable the modem to respond to a ping to its WAN (Internet) port. This feature allows your
modem to be discovered. Enable this feature only as a diagnostic tool or if a specific reason exists.
To change the default WAN security settings: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter 
http://www.routerlogin.net.
A login window opens.
3. Enter the 
modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays.
4. Select 
ADVANCED > Setup > WAN Setup.
The 
WAN Setup page displays.
5. To enable a port scan and disable DoS protection, clear the Disable Port Scan and DoS Protection
chec

k box.
6. To enable the 
modem to respond to a ping, select the Respond to Ping on Internet Port check box.
7. Click the 
Apply button.
Your settings are saved.
Manage NAT Filtering Network Address Translation (NAT) determines how the modem processes inbound traffic. Secured NAT
protects computers on the LAN from attac

ks from the Internet but might prevent some Internet games,
point-to-point applications, or multimedia applications from working. Open NAT provides a much less secured
firewall but allows almost all Internet applications to work. Secured NAT is the default setting.
To change the default NAT filtering settings: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter 
http://www.routerlogin.net.
A login window opens.
3. Enter the 
modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays.
4. Select 
ADVANCED > Setup > WAN Setup. Manage the WAN and LAN Network Settings
56
Broadband High-Speed DSL Modem Model DM200 
						

							The WAN Setup page displays.
5. Select a NAT Filtering radio button:
•Secured. 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. By default, the 
Secured radio button is selected.
• Open
. Provides a much less secured firewall but allows almost all Internet applications to function.
6. Click the 
Apply button.
Your settings are saved.
Manage the SIP Application-Level Gateway The application-level gateway (ALG) for the Session Initiation Protocol (SIP) is enabled by default for
enhanced address and port translation. However, some types of VoIP and video traffic might not work well
when the SIP ALG is enabled. For this reason, the modem provides the option to disable the SIP ALG.
T

o change the default SIP ALG setting: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter 
http://www.routerlogin.net.
A login window opens.
3. Enter the 
modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays.
4. Select 
ADVANCED > Setup > WAN Setup.
The 
WAN Setup page displays.
5. To disable the SIP ALG, select the 
Disable SIP ALG check box.
The SIP ALG is enabled by default.
6. Click the 
Apply button.
Your settings are saved.
Manage IGMP Proxying IGMP proxying allows a computer on the local area network (LAN) to receive the multicast traffic it is interested
in from the Internet. If you do not need this feature, leave it disabled, which is the default setting.
To enable IGMP proxying: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter 
http://www.routerlogin.net
A login window opens. Manage the WAN and LAN Network Settings
57
Broadband High-Speed DSL Modem Model DM200 
						

							3.
Enter the modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays.
4. Select 
ADVANCED > Setup > WAN Setup.
The 
WAN Setup page displays.
5. Clear the Disable IGMP Proxying
 check box.
By default, the 
Disable IGMP Proxying check box is selected and IGMP proxying is disabled.
6. Clic
k the Apply button.
Y

our settings are saved.
Manage the Modem’s LAN IP Address Settings The modem is preconfigured to use private IP addresses on the LAN side and to act as a DHCP server.
The 
modem’s default LAN IP configuration is as follows:
• LAN IP address
. 192.168.5.1 (This is the same as www.routerlogin.net and www.routerlogin.com.)
• Subnet mask
. 255.255.255.0
These addresses are part of the designated private address range for use in private networks and are
suitable for most applications. The IP address and subnet mask identify which addresses are local to a
specific device and which must be reached through a gateway or 
modem.
You might want to change these settings if attach a switch to the 
modem to expand the local network and
you need a specific IP subnet on the network, or if competing subnets use the same IP scheme.
To change the LAN IP address settings: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter 
http://www.routerlogin.net.
A login window opens.
3. Enter the 
modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays. Manage the WAN and LAN Network Settings
58
Broadband High-Speed DSL Modem Model DM200 
						

							4.
Select ADVANCED > Setup > LAN Setup. 5.
In the 
IP Address field, enter the LAN IP address for the modem.
6. In the 
IP Subnet Mask, enter the LAN subnet mask for the modem.
7. Clic
k the 
Apply button.
Your settings are saved.
If you changed the LAN IP address of the modem, you are disconnected when the changes take effect.
To reconnect, close your browser, relaunch it, and log in to the 
modem at its new LAN IP address.
Manage the Router Information Protocol Settings Router Information Protocol (RIP) lets the modem exchange routing information with other routers. By default,
RIP is enabled in both directions (in and out) without a particular RIP version.
To manage the RIP settings: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter http://www.routerlogin.net.
A login windo

w opens.
3. Enter the 
modem user name and password.
The user name is 
admin. The default password is password. The user name and password are
case-sensitive.
The BASIC Home page displays.
4. Select 
ADVANCED > Setup > LAN Setup.
The LAN Setup page displays. Manage the WAN and LAN Network Settings
59
Broadband High-Speed DSL Modem Model DM200 
						

							5.
From the RIP Direction menu, select the RIP direction:
• Both
. The modem broadcasts its routing table periodically and incorporates information that it
receives. This is the default setting.
• Out Only
. The modem broadcasts its routing table periodically but does not incorporate the RIP
information that it receives.
• In Only
. The modem incorporates the RIP information that it receives but does not broadcast its
routing table.
6. From the 
RIP Version menu, select the RIP version:
• Disabled
. The RIP version is disabled. This is the default setting.
• RIP-1
. This format is universally supported. It is adequate for most networks, unless you are using
an unusual network setup.
• RIP-2
. This format 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.
7. Click the 
Apply button.
Your settings are saved.
Manage Reserved LAN IP Addresses When you specify a reserved IP address for a computer on the LAN, that computer always receives the
same IP address each time it accesses the modem’s DHCP server.
Reser

ve a LAN IP Address
You can assign a reserved IP address to a computer or server that requires permanent IP settings.
To reserve an IP address: 1.
Launch a web browser from a computer that is connected to the network.
2. Enter 
http://www.routerlogin.net.
A login window opens.
3. Enter the 
modem user name and password.
The user name is admin. The default password is password. The user name and password are
case-sensitiv

e.
The BASIC Home page displays.
4. Select 
ADVANCED > Setup > LAN Setup.
The LAN Setup page displays.
5. In the Address Reservation section, click the 
Add button.
The Address Reservation page displays.
6. Either select a device from the Address Reservation Table by selecting the corresponding radio button
or specify the reserved IP address information:
•In the IP Address field, enter the IP address to assign to the computer or device. Manage the WAN and LAN Network Settings
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Broadband High-Speed DSL Modem Model DM200