Netgear C7100v High Speed Cable Modem Router User Manual

							Specify Internet Port Settings 
111  AC1900 Cable Modem Voice Router
•For the internal ports, leave the Use the same port range for Internal port check 
box selected.
•Internal IP address. Type the IP address in the Internal IP address field, or select 

9. Click  the Apply  button.
Your settings are saved.
Delete a Port Forwarding Entry
To delete a port forwarding entry:
1. Launch  an  Internet  browser  from  a  computer  or  mobile  device  that  is  connected  to  the 
network.
2. Type http://www.routerlogin.net or http://www.routerlogin.com.
A login window opens.
3. Enter  the  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  >  Port  Forwarding/Port  Triggering.
The Port Forwarding/Port Triggering page displays.
5. Select  the Port  Forwarding  radio  button  as  the  service  type
6. In  the  table,  select  the  radio  button  next  to  the  service  name.
7. Click  the Delete  Service  button.
The service is deleted.
Application Example: Make a Local Web Server Public
t forwarding to allow web 
 
To make a local web server public:
1. Assign your web server either a fixed IP address or a dynamic IP address using DHCP 
address  reservation. 
 an IP address of 
192.168.0.33. 
2. On  the  Port  Forwarding/Port Triggering  page,  configure  the modem  router to forward  the 
HTTP  service  to  the  local  address  of  your  web  server  at 192.168.0.33. 
 
						

							Specify Internet Port Settings 
112 AC1900 Cable Modem Voice Router 
3. (Optional) Register a host name with a Dynamic DNS service, and specify that name in the 
Dynamic  DNS  page.
ternet because you 
can type the name in the Internet browser. Otherwise, you must know the IP address that 
the ISP assigned, which typically changes.
How the Modem Router Implements the Port Forwarding Rule
The following sequence shows the effects of a port forwarding rule:
1. When  you  type  the  URL  www.example.com  in  your  browser,  the  browser  sends  a  web 
page  request  message  with  the  following  destination  information: 
•Destination address. The IP address of www.example.com, which is the address of 
your modem router.
•Destination port number
process.
2. Your modem  router receives  the  message  and  finds  your  port  forwarding  rule  for  incoming 
port  80  traffic. 
3. The modem  router changes  the  destination  in  the  message  to  IP  address  192.168.0.123 
and  sends  the  message  to  that  computer.
4. Your  web  server  at  IP  address  192.168.0.123  receives  the  request  and  sends  a  reply 
message  to  your modem  router.
5. Your modem router performs Network Address Translation (NAT) on the source IP address, 
and sends the reply through the Internet to the computer or mobile device that sent the web 
page  request. 
Set Up Port Triggering
is useful in these cases:
•computer (but not 
simultaneously).
•IHUHQWIURm the outgoing port.
ILFWRWKH Internet from an outbound 
“trigger” port that you specify. For outbound traffic from that port, the modem router saves the 
IP address of the computer that sent the traffic. The modem router temporarily opens the 
rds that incoming traffic to that 
destination.
nge of ports to a single local 
computerputer when needed and 
close the ports when they are no longer needed. 
						

							Specify Internet Port Settings 113
 AC1900 Cable Modem Voice Router
Note:
If you use applications such as multiplayer gaming, peer-to-peer 
connections, real-time communications such as instant messaging, or 
remote assistance (a feature in Windows XP), enable Universal 
Plug-N-Play (UPnP).
Add a Port Triggering Service
To add a port triggering service:
1. Launch 
 an  Internet  browser  from  a  computer  or  mobile  device  that  is  connected  to  the 
network.
2.  T
ype  http://www.routerlogin.net  or http://www.routerlogin.com .
A login window opens.
3.  Enter 
the  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  ADV
 ANCED  > Advanced  Setup  >  Port  Forwarding/Port  Triggering. 
The Port Forwarding/Port Triggering page displays.
5.  Select 
the  Port  Triggering   radio  button.
6.  Click 
the  Add  Service  button.
7. In  the  Service  Name  field,  type  a  descriptive  service  name. 
8.  In 
the  Service  User  menu,  select  Any,  or  select Single  address   and  enter  the  IP  address 
of  one  computer:
• Any  (the default) allows any computer on the Internet to use this service. 
• Single address restricts the service to a particular computer
 . 
9.  Select 
the  service  type,  either  TCP  or UDP  or  TCP/UDP  (both). 
If you are not sure, select TCP/UDP . 
						

							Specify Internet Port Settings 
114 AC1900 Cable Modem Voice Router 
10. In  the Service  Type fields,  enter  the  starting  and  ending  ports. 
11. Enter  the  inbound  connection  port  information  in  the Starting  Port  and Ending  Port  fields.
12. Click  the Apply  button.
The service is now in the Portmap table. You must enable port triggering before the 
d.
Application Example: Port Triggering for Internet Relay Chat 
lies to multiple port 
o open more incoming ports 
when a particular outgoing port starts a session.
An example is Internet Relay Chat (IRC). Your computer connects to an IRC server at 
destination port 6667. The IRC server not only responds to your originating source port, but 
also sends an “identify” message to your computer on port 113. Using port triggering, you can 
tell the modem router, “When you initiate a session with destination port 6667, you must also 
allow incoming traffic on port 113 to reach the originating computer.” The following sequence 
shows the effects of this port triggering rule you defined:
1. You  open  an  IRC  client  program  to  start  a  chat  session  on  your computer. 
2. Your  IRC  client  composes  a  request  message  to  an  IRC  server  using  a  destination  port 
number  of  6667,  the  standard  port  number  for  an  IRC  server  process. Your  computer  then 
sends  this  request  message  to  your modem  router.
3. Your modem  router creates  an  entry  in  its  internal  session  table  describing  this 
communication  session  between  your  computer  and  the  IRC  server. Your modem  router 
stores  the  original  information,  performs  Network Address Translation  (NAT)  on  the  source 
address  and  port,  and  sends  this  request  message  through  the  Internet  to  the  IRC  server. 
4. Noting  your  port  triggering  rule  and  observing  the  destination port  number  of  6667,  your 
modem  router creates  another  session  entry  to  send  any  incoming  port  113  traffic  to  your 
computer.
5. The  IRC  server  sends  a  return  message  to  your modem  router using  the  NAT-assigned 
source port (for example, port 33333) as the destination port. The IRC server also sends an 
“identify”  message  to  your modem  router with  destination  port  113.
6. When  your modem  router receives  the  incoming  message  to  destination  port  33333,  it 
checks its session table to see if a session is active for port number 33333. Finding an active 
session,  the modem  router restores  the  original  address  information  replaced  by  NAT  and 
sends  this  reply  message  to  your  computer.
7. When your modem router receives the incoming message to destination port 113, it checks 
its session table and finds an active session for port 113 associated with your computer. The 
modem  router replaces  the  message’s  destination  IP  address  with  your  computer’s  IP 
address  and  forwards  the  message  to  your  computer.
8. When  you  finish  your  chat  session,  your modem  router eventually  senses  a  period  of 
inactivity  in  the  communications. The modem  router then  removes  the  session  information 
from its session table, and incoming traffic is no longer accepted on port numbers 33333 or 
113. 
						

							115
11
11.   Troubleshooting
e problems you might 
ion here, check the NETGEAR 
support site at http://support.netgear.com for product and contact information.
This chapter contains the following sections:
•Troubleshoot with the LEDs 
•Changes Not Saved 
•Cannot Log In to the Modem Router 
•WiFi Connectivity 
•Phone Does Not Get a Dial Tone 
•Troubleshoot Your Network Using the Ping Utility  
						

							Troubleshooting 
116 AC1900 Cable Modem Voice Router 
Troubleshoot with the LEDs
Y troubleshooting.
Power LED Is Off
•Make sure that the power cord is securely connected to your modem router and securely 
connected to a working power outlet. 
•or this product.
•www.netgear.com/support.
LEDs Never Turn Off
When the modem router is turned on, the LEDs light for about 10 seconds and then turn off. If 
outer.
lowing:
1. Cycle  the  power  to  see  if  the  modem  router  recovers.
2. Press and hold the Reset button to return the modem router to its factory settings. For more 
information,  see 
Factory Settings on  page 123.
technical support at 
netgear.com/support.
Internet LED Is Off
If the Internet LED is off and the modem router is connected to the cable television cable, try 
the following:
•modem router and at the 
wall jack.
•ble Internet service. Your 
modem router service.
•home run” back to the 
point where the cable enters your home.
Troubleshoot the Cable Internet Connection
When your modem router cannot access the Internet and your Internet LED is on, register the 
th your cable Internet 
provider. 
Additionally, check to make sure that the setting for your computer’s TCP/IP gateway is set to 
use the modem router. If your computer obtains its information from the modem router by 
DHCP 
						

							Troubleshooting 
117  AC1900 Cable Modem Voice Router
Cannot Log In to the Modem Router
 or mobile device on your 
local network, check the following:
1. Make  sure  that  you  are  connected  to  the  modem  router’s  wired  or  WiFi  network.
•nnection is secure 

•For a WiFi connection, make sure that you selected the correct network.If you cannot 
ed on (its Power 
that someone turned off 
the SSID broadcast or the turned off the WiFi radios. See 
WiFi Connectivity on 
page 11 8.
2. If you are connected to the modem router network, but the web browser does not display the 
login  window,  check  the  following:
•Make sure that Java, JavaScript, or ActiveX is enabled in your browser. If you are 
using Internet Explorer, click the Refresh button to be sure that the Java applet is 
loaded.
•Try quitting the browser and launching it again.
3. If  the  browser  displays  the  login  window,  but  you  cannot  access  the  modem  router,  make 
sure  that  you  are  using  the  correct  login  information. 
The user name is admin, and the default password is password. Both are 
case-sensitive. Make sure that Caps Lock is off when you enter this information.
4. If you customized advanced home network settings such as the IP address scheme, check 
the  following:
•Make sure that the IP address of your computer is on the same subnet as the modem 
r computer’s 

•If your computer’s IP address is shown as 169.254.x.x, recent versions of Windows 
nnot reach a 
DHCP server. These autogenerated addresses are in the range of 169.254.x.x. If 
 computer to the 
modem router, and reboot your computer.
•If your modem router’s IP address was changed and you do not know the current IP 
address, clear the modem router’s configuration to factory defaults. This sets the 
modem router’s IP address to 192.168.0.1. For more information, see 
Factory 
Settings on page 123. 
						

							Troubleshooting 
118 AC1900 Cable Modem Voice Router 
Changes Not Saved
odem router interface, 
check the following:
•Apply button before moving to 
another page or tab, or your changes are lost. 
•Click the Refresh or Reload button in the web browser. It is possible that the changes 

						

							Troubleshooting 
119  AC1900 Cable Modem Voice Router
-on.
Is your modem router too far from your computer, or too close? Place your computer 
and see if the signal 
strength improves.
nal. See Position Your 
Modem Router on page 13.
Phone Does Not Get a Dial Tone 
To troubleshoot a phone without a dial tone:
1. Check  the  modem  router  LEDs:
ving power.
nnected to the Internet.
The T this LED is off, the phone 
I the hook.
If the Tolid, proceed to the following 
step.
2. Make  sure  that  the  phone  cable  is  securely  connected  to  the  telephone  and  to  the  phone 
port  on  the  modem  router.
3. Connect  a  different  phone  and  see  if  the  other  phone  gets  a  dial  tone.
4. Connect  a  different  phone  cable. 
5. Plug  the  modem  router  in  to  a  different  electrical  outlet.
6. Contact  your  service  provider.
Troubleshoot Your Network Using the Ping Utility
Most network devices and routers contain a ping utility that sends an echo request packet to 
the designated device. The device then responds with an echo reply. You can easily 
or workstation. 
Test the LAN Path to Your Modem Router
Y the LAN path to your 
modem router is set up correctly.
To ping the modem router from a Windows computer:
1. From  the  Windows  toolbar,  click Start  and  select Run.
2. In  the  field  provided,  type ping  followed  by  the  IP  address  of  the  modem  router,  as  in  this 
example: 
						

							Troubleshooting 
120 AC1900 Cable Modem Voice Router 
ping www.routerlogin.net
3. Click  the OK  button.
You should see a message like this one:
Pinging  with 32 bytes of data
If the path is working, you see this message:
Reply from < IP address >: bytes=32 time=NN ms TTL=xxx
If the path is not working, you see this message:
Request timed out
If the path is not functioning correctly, you might be experiencing one of the following 
problems:
•Wrong physical connections
D is lit for the port to 
which you are connected.
. If your modem router 
and computer are connected to a separate Ethernet switch, make sure that the link LEDs 
r and modem router.
•Wrong network configuration
Verify that the Ethernet card driver software and TCP/IP software are both installed and 
configured on your computer. 
Vter are correct and that 
the addresses are on the same subnet.
Test the Path From Your Computer to a Remote Device
After verifying that the LAN path works correctly, test the path from your computer to a remote 
device.
1. From  the  Windows  toolbar,  click  the Start  button  and  select Run.
2. In  the  Windows  Run  window,  type
ping -n 10 
 your ISP DNS server.
If the path is functioning correctly, messages like those shown in the previous section display.

• the default gateway on 
your computer. If DHCP assigns the IP configuration of your computers, this information 
is not visible in your computer Network Control Panel. Verify that the IP address of the 
modem router is listed as the default gateway.