Asus Router RX3042H User Manual

							
ix
RX3042H User's Manual Introduction
Figure 10.8 Factory Reset Page  ..................................................97
Figure 10.9 Factory Reset Confirmation ......................................
97
Figure 10.10 Factory Reset Count Down Timer ...........................
97
Figure 10.11 Backup System Configuration Page  ........................
98
Figure 10.12 Restore System Configuration Page  .......................
99
Figure 10.13 Selecting System Configuration from the File Manager     
                      ................................................................................. 100
Figure 10.14 System Configuration Restoration Confirmation ...
100
Figure 10.15 System Reboot Counter Timer ..............................
101
Figure 10.16 Firmware Upgrade Page  .......................................101
Figure 10.17 Selecting Firmware from the File Manager  ...........102
Figure 10.18 Firmware Upgrade Confirmation ...........................
102
Figure 10.19 Firmware Upgrade Progress  .................................102
Figure 10.20 System Reboot Count Down Timer for Firmware        
  
                     Upgrade  .................................................................103
Figure 10.21 Restart System Page  ............................................104
Figure 10.22 Configuration Manager Logout Page  ....................
104
Figure 10.23 Confirmation for Closing Browser (IE)  ...................
104
Figure 12.1 Using the ping Utility ................................................111
Figure 12.2 Using the nslookup Utility  .........................................113
List of Tables
Table 2.1 DoS Attacks ....................................................................5
Table 2.2 Front Panel Label and LEDs  ...........................................
7
Table 2.3 Rear Panel Labels and LEDs  .........................................
8
Table 3.1 LED Indicators  ..............................................................
13
Table 3.2 Default Settings Summary  ............................................
21
Table 4.1 Description of Commonly Used Buttons and Icons  ......
25 
						

							
x
Introduction RX3042H User's Manual

Table 5.1 LAN Configuration Parameters .....................................28
Table 5.2 WAN PPPoE Configuration Parameters  .......................
31
Table 5.3 WAN PPPoE Unnumbered Configuration Parameters  .
34
Table 5.4 WAN Static IP Configuration Parameters  .....................
37
Table 5.5 WAN PPTP Configuration Parameters  .........................
39
Table 5.6 WAN Load Balancing and Line Back Up Configuration     
                            
                Parameters  ...................................................................42
Table 6.1 DHCP Configuration Parameters  ..................................
47
Table 6.2 Fixed DHCP Lease Configuration Parameters  .............
49
Table 7.1 Static Route Configuration Parameters  ........................
54
Table 7.2 Static Route Configuration Parameters  ........................
56
Table 8.1 DDNS Configuration Parameters  ..................................
60
Table 9.1 Firewall Options Parameters  ........................................
67
Table 9.2 DoS Attack Definition  ....................................................
68
Table 9.3 ACL Rule Configuration Parameters  .............................
71
Table 9.4 Service Configuration Parameters  ................................
73
Table 9.5 Virtual Server Configuration Parameters  ......................
81
Table 9.6 Port Numbers for Popular Applications  .........................
82
Table 9.7 Special Application Configuration Parameters  ..............
86
Table 9.8 Port Numbers for Popular Applications  .........................
86
Table 10.1 SNMP Configuration Parameters  ................................
94
Table 11.1 IP Address Structure .................................................
106 
						

							
1
RX3042H User's Manual Introduction

Chapter 1  Introduction
Congratulations  on  becoming  the  owner  of  RX3042H.  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's  Manual  will  show  you  how  to  set  up  the  RX3042H, 
and  how  to  customize  its  configuration  to  get  the  most  out  of  this 
product.
1.1 Features
  •  LAN: 4-port Fast Ethernet switch
 •  WAN: Dual 10/100Base-T Ethernet ports to provide Internet  
    acc
ess for all computers on your LAN
 •  Firewall, and NAT (Network Address Translation) functions to  
    provide secure Internet access for you
r LAN
  •   Automatic network address assignment through DHCP Server 
 
    Services including IP route, DNS and DDNS configuration
 •  Configuration program accessible via a web browser, such as  
    Microsoft Internet Explorer 6.0 or newer.
 •  User configuration dual-WAN or WAN plus DMZ support
•  USB storage support (to be supported with firmware upgrade)
1.2 System Requirements
In order to use the RX3042H for Internet access, you must have the 
following:
  •
   ADSL or cable modem and the corresponding service up and  
    running, with at least one public Internet address assigned to  
    your WAN
  •  One or more computers each containing an Ethernet 10Base-T  
    or 100Base-T or 1000Base-T network interface card (NIC)
  •
  (Optional) An Ethernet hub/switch, if you want to connect the  
    router to more than four computers on an Ethernet network. 
						

							
2
Introduction RX3042H User's Manual
  •  For system configuration using the web-based GUI: a web  
    browser such as Internet Explorer 6.0 or newer.
1.3  Using this Document
1.3.1  Notational conventions
  •  Acronyms are defined the first time they appear in the text.
  •  For brevity, RX3042H is sometimes referred to as the “router”  
    or the ”gateway”.
  •  The terms LAN and network are used interchangeably to refer  
    to a group of Ethernet-connected computers at one site.
  •  Sequence of mouse actions is denoted by the “->” character.  
    For instance, 
System -> Network Setup means click the  
   
System menu and then click the Network Setup submenu.
1.3.2  Typographical conventions
  •  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. 
						

							
RX3042H User's Manual Getting to Know RX3042H
3
Chapter 2  Getting to Know RX3042H
2.1  Parts List
In addition to this document,  RX3042H should come with the following:
•  The system unit
•  AC adapter
•  Ethernet cable (“straight-through” type)
2.2  Hardware Features
LAN
•  4-port Fast Ethernet switch
•  Auto speed negotiation
WAN
•  Dual 10/100M Ethernet ports
•  Auto MDI/MDIX
2.3  Software Features
2.3.1  NAT Features
RX3042H  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.  RX3042H  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 RX3042H.•    NAPT  (Network Address  and  Port  Translation)– Also  called  IP  Masqueradi  ng  or  ENAT  (Enhanced  NAT).  Maps  many  internal 
hosts to only one globally valid IP address. The mapping usually  
						

							
Getting to Know RX3042H RX3042H User's Manual
4

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.
•    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. 
2.3.2  Firewall Features
The  firewall  as  implemented  in  RX3042H  provides  the  following 
features to protect your network from being attacked and to prevent 
your network from being used as the springboard for attacks.
•  Stateful Packet Inspection
•  Packet Filtering (ACL)
•  Defense against Denial of Service Attacks
•  Log
2.3.2.1  Stateful Packet Inspection
The  RX3042H  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. 
						

							
RX3042H User's Manual Getting to Know RX3042H
5

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 RX3042H Firewallʼs ACL methodology supports:
•  Filtering based on destination and source IP address, port  
  number and protocol
•  Use of the wild card for composing filter rules
•  Filter Rule priorities
2.3.2.3  Defense against DoS Attacks
The RX3042H 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  RX3042H  Firewall  provides 
protection  from  “WinNuke”,  a  widely  used  program  to  remotely 
crash unprotected Windows systems in the Internet. The RX3042H 
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 provided by the RX3042H is listed in  
Table 2.1.
Table 2.1. DoS Attacks
Type of Attack Name of Attacks
Re-assembly Attacks Bonk,  Boink,  Teardrop  (  New  Tear), 
Overdrop,  Opntear,  Syndrop,  Jolt,  IP 
fragmentation overlap.
ICMP Attacks Ping of Death, Smurf, Twinge
FloodersLogging only for ICMP Flooder, UDP 
Flooder, SYN Flooder
Port ScansLogging  only  for  TCP  SYN  Scan, 
A t t a c k i n g   p a c k e t s   d r o p p e d :   T C P 
XMAS  Scan,  TCP  Null  Scan,  TCP 
Stealth Scan
Protection with PF RulesEcho-Chargen, Ascend Kill
Miscellaneous Attacks IP Spoofing, LAND, Targa, Winnuke 
						

							
Getting to Know RX3042H RX3042H User's Manual
6

2.3.2.4  Application Level Gateway (ALG)
Applications  such  as  FTP  open  connections  dynamically  based 
on  the  respective  application  parameter.  To  go  through  the  firewall 
on  the  RX3042H,  packets  pertaining  to  an  application,  require  a 
corresponding allow rule. In the absence of such rules, the packets 
will  be  dropped  by  the  RX3042H  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  RX3042H  NAT 
provides  a  number  of ALGs  for  popular  applications  such  as  FTP, 
and Netmeeting.
2.3.2.5  Log
Events  in  the  network,  that  could  be  attempts  to  affect  its  security, 
are  recorded  in  the  RX3042H  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. 
						

							
RX3042H User's Manual Getting to Know RX3042H
7

Table 2.2 Front Panel Label and LEDs
LED  LabelColorStatusIndication
1PowerGreenONRX3042H is powered on.
OFFRX3042H is powered off.
2StatusGreen
3
USB Identifies the USB port.
1-2GreenOFFUSB device is not detected.
ONUSB device is detected.
4WAN
Identifies the WAN port.1-2
OFFNo link is detected.
GreenON100Mbps link is detected.
Blinking100Mbps activity is detected.
AmberON10Mbps link is detected.
Blinking10Mbps activity is detected.
5
LAN Identifies the LAN port.
1-4
OFFNo link is detected.
GreenON100Mbps link is detected.
Blinking100Mbps activity is detected.
AmberON10Mbps link is detected.
Blinking10Mbps activity is detected.
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 Label and LEDs
12345 
						

							
Getting to Know RX3042H RX3042H User's Manual
8

Table 2.3 Rear Panel Labels and LEDs
LabelIndication
61--4
LAN  Ports: connect to your PC's Ethernet 
port, or to the uplink port on your LAN's 
hub/switch, using the Ethernet cable.
7Dual WAN or 
WAN + DMZ WAN ports:Connect to your WAN device, 
such as ADSL or cable modem.
8USBUSB Ports: connect to USB 1.1 OR 2.0 
devices
9Console
10RESET
Reset Button:
1. Reboot the device
2. Reset the system configuration to 
factory defaults if pressed for more than 5 
seconds.
 11
POWER Power  Input  Jack:  Connect  to  the  supplied 
AC adapter.
2.4.2  Rear Panel
The  rear  panel  contains  the  ports  for  the  unitʼs  data  and  power 
connections.
Figure 2.2 Rear Panel Labels and Connectors
67891011