User's Manual
Table Of Contents
- AC1200 WiFi Cable Modem Router
- Contents
- 1. Hardware Setup
- 2. Connect to the Network and Access the Modem Router
- 3. Specify Initial Settings
- 4. Control Access to the Internet
- 5. Share a USB Storage Device Attached to the Modem Router
- USB Device Requirements
- Connect a USB Storage Device to the Modem Router
- Access a USB Drive Connected to the Modem Router From a Windows Computer
- Map a USB Device to a Windows Network Drive
- Access a USB Storage Device That Is Connected to the Modem Router From a Mac
- Control Access to the USB Drive
- Use FTP Within the Network
- View or Change Network Folders on a USB Drive
- Add a Network Folder on a USB Storage Device
- Edit a Network Folder on a USB Storage Device
- Approve USB Storage Devices
- Safely Remove a USB Storage Device
- 6. Specify Network Settings
- View or Change the WAN Settings
- Change the MTU Size
- Set Up a Default DMZ Server
- Change the Modem Router’s Device Name
- Change the LAN TCP/IP Settings
- Specify the IP Addresses That the Modem Router Assigns
- Manage LAN IP Addresses
- Use the WPS Wizard for WiFi Connections
- Specify Basic WiFi Settings
- Change the WiFi Security Option
- Set Up a WiFi Guest Network
- Control the WiFi Radios
- Specify WPS Settings
- Set Up a WiFi Access List
- Dynamic DNS
- Improve Network Connections With Universal Plug-N-Play
- 7. Manage Your Network
- View Modem Router Status
- Reboot the Modem Router
- Change the Router Mode
- View and Manage Logs of Modem Router Activity
- Manage the Modem Router Configuration File
- Change the admin Password
- View Event Logs
- Run the Ping Utility
- Run the Traceroute Utility
- View WiFi Access Points in Your Area
- View or Change the Modem Router WiFi Channel
- Remote Management
- Control the LED Settings
- 8. Specify Internet Port Settings
- 9. Troubleshooting
- A. Supplemental Information
Specify Internet Port Settings
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AC1200 WiFi Cable Modem Router Model C6220
5. Select the Port Triggering radio button.
6. Select a radio button to specify when you want to use port triggering:
• Never.
The modem router does not use port triggering even if you specified port
triggering settings.
• Always.
Always use port triggering.
7. In the Port T
riggering Timeout field, enter a value up to 9999 minutes.
This value controls how long the inbound ports stay open when the modem router detects
no activity
. This value is required because the modem router cannot detect when the
application terminates.
Application Example: Port Triggering for Internet Relay Chat
Some application servers, such as FTP and IRC servers, send replies to multiple port
numbers. Using port triggering, you can tell the modem router to 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:
1. Y
ou open an IRC client program to start a chat session on your computer.
2. Y
our 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. Y
our 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.










