Asus Router RX3141 User Manual

							RX3141 User’s Manual Chapter 1. Introduction 
1 Introduction 
Congratulations on becoming the owner of RX3141. Your LAN (local area network) will now be able to access 
the Internet using your high-speed broadband connection such as those with ADSL or cable modem. 
This User Manual will show you how to set up the RX3141, and how to customize its configuration to get the 
most out of this product. 
1.1 Features 
f  LAN: 4-port Gigabit switch, jumbo frame supports up to 9Kbyte. 
f  WAN: 10/100Base-T Ethernet provides Internet access for all computers on your LAN 
f  Firewall &  NAT (Network Address Translation) functions provide secure Internet access for your LAN 
f  Automatic network address assignment through DHCP Server 
f  Services including IP route, DNS and DDNS configuration 
f  Configuration program accessible via a web browser, such as Microsoft Internet Explorer 6.0 or newer. 
1.2 System Requirements 
In order to use the RX3141 for Internet access, you must have the following: 
f  ADSL or cable modem and the corresponding service up and running, with at least one public Internet 
address assigned to your WAN 
f  One or more computers each containing an Ethernet 10Base-T or 100Base-T or 1000Base-T network 
interface card (NIC) 
f  (Optional) An Ethernet hub/switch, if you want to connect the router to more than four computers on 
an Ethernet network. 
f  For system configuration using the web-based GUI: web browser such as Microsoft IE 6.0 or newer.  
						

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1.3  Using this Document 
1.3.1 Notational conventions 
f  Acronyms are defined the first time they appear in the text. 
f  For brevity, RX3141 is sometimes referred to as the “router” or the ”gateway”. 
f The terms LAN and network are used interchangeably to refer to a group of Ethernet-connected 
computers at one site. 
f  Sequence of mouse actions is denoted by the “Δ character. For instance, Router Setup Î 
Connection means double click the Router Setup menu and then click the Connection submenu. 
1.3.2 Typographical conventions 
f Boldface type text is used for items you select from menus and drop-down lists, and text strings you 
type when prompted by the program. 
1.3.3 Special messages 
This document uses the following icons to call your attention to specific instructions or explanations. 
 
Note Provides clarification or non-essential information on the current 
topic. 
 
 
Definition Explains terms or acronyms that may be unfamiliar to many 
readers. These terms are also included in the Glossary. 
 
 
WARNING 
Provides messages of high importance, including messages 
relating to personal safety or system integrity. 
  
						

							RX3141 User’s Manual Chapter 2. Getting to Know  
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2 Getting to Know RX3141 
2.1 Parts List 
In addition to this document,  RX3141 should come with the following: 
f  The System unit, RX3141 
f AC Adapter 
f User Manual 
f  Compact Disk of Multi-language Quick installation Guide 
2.2 Hardware Features 
f LAN 
• 4-port Gigabit switch 
•  Auto speed negotiation 
•  9KB jumbo frame support 
•  4K MAC address table w/ auto learning and aging 
f WAN 
• 10/100M Ethernet 
•   Auto MDI/MDIX 
2.3 Software Features 
2.3.1 NAT Features 
RX3141 provides NAT to share a single high-speed Internet connection and to save the cost of multiple 
connections required for the hosts on the LAN segments connected to it. This feature conceals network 
address and prevents them from becoming public. It maps unregistered IP address of hosts connected to the 
LAN with valid ones for Internet access. RX3141 also provides reverse NAT capability, which enables users to 
host various services such as e-mail servers, web servers, etc. The NAT rules drive the translation 
mechanism. The following types of NAT are supported by RX3141. 
f  NAPT (Network Address and Port Translation) – Also called IP Masquerading or ENAT (Enhanced 
NAT). Maps many internal hosts to only one globally valid IP address. The mapping usually contains a 
pool of network ports to be used for translation. Every packet is translated with the globally valid IP 
address; the port number is translated with a free pool from the pool of network ports. 
f  Reverse NAPT – Also called inbound mapping, port mapping, or virtual server. Any packet coming to 
the router can be relayed to an internal host based on the protocol, port number and/or IP Address 
specified in the rule. This is useful when multiple services are hosted on different internal hosts.   
						

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2.3.2 Firewall Features 
The firewall as implemented in RX3141 provides the following features to protect your network from being 
attacked and to prevent your network from being used as the springboard for attacks. 
f  Stateful Packet Inspection 
f Packet Filtering (ACL) 
f  Defense against Denial of Service Attacks 
f Log 
2.3.2.1 Stateful Packet Inspection 
The RX3141 Firewall uses “stateful packet inspection” that extracts state-related information required for the 
security decision from the packet and maintains this information for evaluating subsequent connection 
attempts. It has awareness of application and creates dynamic sessions that allow dynamic connections so 
that no ports need to be opened other than the required ones. This provides a solution which is highly secure 
and that offers scalability and extensibility. 
2.3.2.2  Packet Filtering – ACL (Access Control List) 
ACL rule is one of the basic building blocks for network security. Firewall monitors each individual packet, 
decodes the header information of inbound and outbound traffic and then either blocks the packet from 
passing or allows it to pass based on the contents of the source address, destination address, source port, 
destination port, and protocol defined in the ACL rules. 
ACL is a very appropriate measure for providing isolation of one subnet from another. It can be used as the 
first line of defense in the network to block inbound packets of specific types from ever reaching the protected 
network. 
The RX3141 Firewall’s ACL methodology supports: 
f  Filtering based on destination and source IP address, port number and protocol 
f  Use of the wild card for composing filter rules 
f  Filter Rule priorities 
2.3.2.3  Defense against DoS Attacks 
The RX3141 Firewall has an Attack Defense Engine that protects internal networks from known types of 
Internet attacks. It provides automatic protection from Denial of Service (DoS) attacks such as SYN flooding, 
IP smurfing, LAND, Ping of Death and all re-assembly attacks. For example, the RX3141 Firewall provides 
protection from “WinNuke”, a widely used program to remotely crash unprotected Windows systems in the 
Internet. The RX3141 Firewall also provides protection from a variety of common Internet attacks such as IP 
Spoofing, Ping of Death, Land Attack, and Reassembly attacks. 
The type of attack protections/detections provided by the RX3141 is listed in Table 2.1.  
						

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Table 2.1. DoS Attacks 
Type of Attack  Name of Attacks 
Re-assembly attacks Bonk, Boink, Teardrop (New Tear), Overdrop, 
Opentear, Syndrop, Jolt, IP fragmentation overlap 
ICMP Attacks  Ping of Death, Smurf, Twinge 
Flooders Logging only for ICMP Flooder, UDP Flooder, SYN 
Flooder 
Port Scans Logging only for TCP SYN Scan  
Attack packets dropped: TCP XMAS Scan, TCP Null 
Scan, TCP Stealth Scan 
Protection with PF Rules  Echo-Chargen, Ascend Kill 
Miscellaneous Attacks  IP Spoofing, LAND, Targa, Winnuke 
2.4.1.1  Application Level Gateway (ALG) 
Applications such as FTP open connections dynamically based on the respective application parameter. To go 
through the firewall on the RX3141, packets pertaining to an application, require a corresponding allow rule. In 
the absence of such rules, the packets will be dropped by the RX3141 Firewall. As it is not feasible to create 
policies for numerous applications dynamically (at the same time without compromising security), intelligence 
in the form of Application Level Gateways (ALG), is built to parse packets for applications and open dynamic 
associations. The RX3141 NAT provides a number of ALGs for popular applications such as FTP, and 
Netmeeting. 
2.4.1.2 Log 
Events in the network, that could be attempts to affect its security, are recorded in the RX3141 system log file. 
The log maintains a minimum log details such as, time of packet arrival, description of action taken by Firewall 
and reason for action.  
						

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2.4 Finding Your Way Around 
2.4.1 Front Panel 
The front panel contains LED indicators that show the status of the unit. 
 
Figure 2.1. Front Panel LEDs 
 
 Table 2.2. Front Panel Label and LEDs 
 LED Label Color Status Indication 
○1 POWER Green ON 
OFF RX3141 is powered on 
RX3141 is powered off 
○2 1 – 4   Identifies the LAN port LEDs. Status of 
each LAN port is indicated by 3 LEDs: 
STATUS, SPEED and DUPLEX. 
○3 STATUS Green  ON 
Blinking 
 
OFF Ethernet link is established and active 
Data is transmitted or received via the 
connection 
No Ethernet link 
○4 SPEED Green 
Amber ON 
ON 
OFF Speed is 1000Mbps 
Speed is 100Mbps 
Speed is 10Mbps or no link is 
established. 
○5 DUPLEX Amber ON 
 
Blinking 
 
 
OFF The LAN port is operating in full-duplex 
mode. 
The LAN port is operating in half-
duplex mode and collision is 
occurring. 
The LAN port is operating in half 
duplex mode and no collision is 
detected. 
○6 WAN     Identifies the WAN port LED 
○3 STATUS Green  ON 
OFF Ethernet link is established and active. 
No Ethernet link is established. 
○4 SPEED Green  ON 
Blinking Speed is 100Mbps 
Green: Data is transmitted or received 
via the connection 
○1 ○2
○3
○4○5
○6 
						

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 LED Label Color Status Indication 
Amber ON 
Blinking Speed is 10Mbps 
Data is transmitted or received via the 
connection 
  OFF  No link is established. 
○5 DUPLEX Amber ON 
 
OFF The LAN port is operating in full-duplex 
mode. 
The LAN port is operating in half 
duplex mode and no collision is 
detected. 
2.4.2 Rear Panel 
The rear panel contains the ports for the units data and power connections. 
 
Figure 2.2. Rear Panel Connectors 
 
Table 2.3. Rear Panel Labels and LEDs 
 Label Indication 
○7 1 – 4 LAN Ports: connects to your PCs Ethernet port, or 
to the uplink port on your LANs hub/switch, using 
the Ethernet cable. 
○8 WAN WAN Port: connects to your WAN device, such as 
ADSL or cable modem. 
○9 RESET Reset Button 
1. Reboots the device 
2.  Resets the system configuration to the factory 
defaults if pressed for more than 5 seconds. 
○10 POWER Power Input Jack: connects to the supplied AC 
adapter 
 
○7 ○8○9○10 
						

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2.4.3 Bottom View 
 
○
11 Wall Mount Slots: You may use these slots to hang RX3141 on the wall to save space. Depending on your 
particular requirement by taking into account the location of the power outlet, power cord length, Ethernet 
cable length and etc., you can hang RX3141 in 4 different orientations: front panel up, rear panel up, left 
side up or right side up. 
○
12 Magnets: The magnets allow you to place RX3141 on any metal surface to save space. 
○11 ○11
○11○12○11 ○12 
						

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2.5 Placement Options 
Depending on your environment, you may choose one of the three supported placement options for RX3141 – 
desktop placement, magnet mount and wall mount. 
2.5.1 Desktop Placement 
You may place RX3141 on any flat surface. The space-saving design of RX3141 occupies only a small area 
on your desk. 
2.5.2  Magnet Mount Instructions 
Place RX3141 onto any metal surface that attracts magnet, such as most desktop computer housings, 
cabinets and etc. 
2.5.3 Wall Mount Instructions: 
1.  Attach two screws on the wall, separated by 115mm if you want the front or rear panel facing 
upward, 76mm if you want left or right side facing upward. Make sure that the two screws are 
leveled. Note that there are four wall mount slots and you may choose any adjacent slots for wall 
mounting. 
 
2.  Line up the wall mount slots with the screws and maneuver RX3141 so that both screws are 
inserted into the wall mount slots as indicated in the following figures. 
 
 
 
Line up the wall mount slots w/ both screws.   115mm or 76mm
Screws 
Wall 
mount 
slots Screws
Wall 
mount 
slots 
Maneuver the switch so that both screws 
are inserted into the wall mount slots.