Allied Telesis AT-AR240E User manual

Copyright © 2002 Allied Telesyn International, Corp.
960 Stewart Drive Suite B, Sunnyvale CA 94086, USA.
Part Number: 613-50197-00 Rev C
All rights reserved. No part of this publication may be reproduced without
prior written permission from Allied Telesyn.
Allied Telesyn International, Corp. reserves the right to make changes in
specifications and other information contained in this document without
prior written notice. The information provided herein is subject to change
without notice. In no event shall Allied Telesyn be liable for any incidental,
special, indirect, or consequential damages whatsoever, including but not
limited to lost profits, arising out of or related to this manual or the
information contained herein, even if Allied Telesyn has been advised of,
known, or should have known, the possibility of such damages. All
trademarks are the property of their respective owners

AT-AR240E ADSL Bridge/Router Web Interface User Manual 3
Contents
Purpose of this Manual....................................................................................................... 9
Intended Audience.............................................................................................................. 9
Structure of this Manual.................................................................................................... 10
Standards and Protocols .................................................................................................. 11
Supported Standards and Protocols................................................................................. 11
Obtaining Copies of Internet Protocols and Standards..................................................... 11
Background Reading ........................................................................................................ 12
Publicly Accessible Documents........................................................................................ 13
Conventions...................................................................................................................... 13
CHAPTER 1 Overview ............................................................................................................ 14
Introduction....................................................................................................................... 14
Overview of the AT-AR240E ADSL Bridge/Router ........................................................... 14
How to start the web interface .......................................................................................... 15
Performing Basic Tasks.................................................................................................... 17
Status ............................................................................................................................... 17
User Management ............................................................................................................ 18
Error Log........................................................................................................................... 19
Save Configuration ........................................................................................................... 20
Restart .............................................................................................................................. 21
CHAPTER 2 Configuring the ADSL Interface ....................................................................... 22
Introduction to ADSL ........................................................................................................ 22
Internet Connectivity......................................................................................................... 22
Branch Office Connectivity ............................................................................................... 22
Telecommuting ................................................................................................................. 23
Business-to-Business ....................................................................................................... 23
Content Delivery ............................................................................................................... 23
ADSL services .................................................................................................................. 23
MULTI (AUTO).................................................................................................................. 24
ANSI T1.413 and G.DMT.................................................................................................. 24
G.Lite ADSL...................................................................................................................... 25
ATM Parameters............................................................................................................... 25
ATM Channel Parameters ................................................................................................ 26
ATM Quality of Service Parameters ................................................................................. 26
Configuring the Connection type ...................................................................................... 27
Encapsulation ...................................................................................................................28
AT-AR240E as a bridge.................................................................................................... 28
RFC 1483 Bridged/Routed Connection ............................................................................ 29
Configuration Example for an RFC1483 Bridged Connection .......................................... 29
Configuration Example for an RFC1483 Routed Connection ........................................... 30
IP over ATM connection ................................................................................................... 31
Configuration Example for an IP over ATM Connection................................................... 31
PPP over ATM Bridged/Routed connection...................................................................... 32
Configuration Example for a PPP over ATM bridged Connection .................................... 32
Configuration Example for a PPP over ATM Routed Connection..................................... 33
PPP Over Ethernet Routed Connection ........................................................................... 34
PPP Over Ethernet introduction ....................................................................................... 34
Configuration Example for a PPP over Ethernet Routed Connection............................... 35
CHAPTER 3 LAN - USB .......................................................................................................... 37

IP Protocol Introduction .................................................................................................... 37
The Internet ...................................................................................................................... 37
Addressing........................................................................................................................ 39
Subnets ............................................................................................................................ 41
Changing the AT-AR240E LAN - USB IP address ........................................................... 43
IP Routing......................................................................................................................... 44
CHAPTER 4 DHCP .................................................................................................................. 46
The Dynamic Host Configuration Protocol ....................................................................... 46
The AT-AR240E’s support for DHCP ............................................................................... 47
DHCP Relay ..................................................................................................................... 47
DHCP Server.................................................................................................................... 49
CHAPTER 5 DNS..................................................................................................................... 52
DNS introduction .............................................................................................................. 52
DNS Relay........................................................................................................................ 53
DNS Client........................................................................................................................ 54
CHAPTER 6 Security .............................................................................................................. 55
Introduction....................................................................................................................... 55
Application Gateway......................................................................................................... 55
Stateful Inspection ............................................................................................................ 56
Firewall ............................................................................................................................. 57
Dynamic Port Opening ..................................................................................................... 57
Attack Detection and Blocking.......................................................................................... 57
NAT .................................................................................................................................. 58
Security interfaces ............................................................................................................ 58
Firewall ............................................................................................................................. 60
Precedence rule for overlapping filters ............................................................................. 65
Configuration example 1 for Firewall ................................................................................ 65
Dynamic Port Opening ..................................................................................................... 67
Configuration example 1 for Dynamic Port Opening ........................................................ 71
Configuration example 2 for Dynamic Port Opening ........................................................ 74
Attack Detection and Blocking.......................................................................................... 76
NAT .................................................................................................................................. 77
Configuration example 1 for NAT ..................................................................................... 81
Configuration example 2 for NAT ..................................................................................... 83
Configuration example 3 for NAT ..................................................................................... 84
Configuration example 4 for NAT ..................................................................................... 85
Interactions of NAT and other security features. .............................................................. 87
Firewall filters and Reserved mappings............................................................................ 87
NAT and Dynamic Port Opening ...................................................................................... 87
CHAPTER 7 SNMP .................................................................................................................. 88
Introduction....................................................................................................................... 88
Simple Network Management Protocol (SNMP)............................................................... 88
Communities and Views ................................................................................................... 88
AT-AR240E Console ........................................................................................................ 89
How to close the console.................................................................................................. 91
HELP on SNMP console commands................................................................................ 92
Command Reference ....................................................................................................... 93
CHAPTER 8 APPENDIX A....................................................................................................... 95
Factors underlying the design of ATM.............................................................................. 95
LAN/WAN/Voice integration.............................................................................................. 96
Cell multiplexing ...............................................................................................................96

AT-AR240E ADSL Bridge/Router Web Interface User Manual 5
Other significant features of ATM ..................................................................................... 97
Traffic engineering features.............................................................................................. 97
Encapsulation of protocols ............................................................................................... 97
Scalability ......................................................................................................................... 97
BASIC STRUCTURE OF ATM NETWORK...................................................................... 98
ATM SERVICES............................................................................................................... 98
ATM VIRTUAL CONNECTIONS ...................................................................................... 99
ATM and Quality of Service.............................................................................................. 99
UBR (unspecified bit rate)............................................................................................... 100
CBR (constant bit rate) ................................................................................................... 100
Real time VBR ................................................................................................................ 100
Non-real time VBR.......................................................................................................... 100
ABR (available bit rate) and QFC ................................................................................... 101
Traffic Parameters .......................................................................................................... 101
Peak Cell Rate (PCR)..................................................................................................... 101
Minimum Cell Rate (MCR).............................................................................................. 101
Sustainable Cell Rate (SCR) .......................................................................................... 102
Maximum Burst Size (MBS) and Burst Tolerance (BT) .................................................. 102
CHAPTER 9 APPENDIX B..................................................................................................... 103
RFC1483 Bridged/Routed .............................................................................................. 103
Data processing sequence ............................................................................................. 103
CHAPTER 10 APPENDIX C..................................................................................................... 105
IP Over ATM................................................................................................................... 105
The inherent complexity in defining an IP network over ATM......................................... 105
Connection-oriented vs. Connectionless ........................................................................ 105
QoS-aware vs. Best Effort .............................................................................................. 106
How IPoA operates......................................................................................................... 106
Routing between LISs .................................................................................................... 107
CHAPTER 11 APPENDIX D..................................................................................................... 108
Point to Point Protocol .................................................................................................... 108
PPP over ATM................................................................................................................ 109
CHAPTER 12 APPENDIX E..................................................................................................... 111
Network Address Translation.......................................................................................... 111
Address conservation ..................................................................................................... 111
Security........................................................................................................................... 112
How does NAT work?..................................................................................................... 112
What about protocols other than UDP and TCP?........................................................... 114
How can you let sessions into servers on the private LAN?........................................... 114
CHAPTER 13 APPENDIX F ..................................................................................................... 116
AT-AR240E Remote management................................................................................. 116
CHAPTER 14 APPENDIX G .................................................................................................... 120
AT-AR240E – How to update the software using the TFTP software............................. 120
How to upload the recovery............................................................................................ 120
How to upload the software image ................................................................................. 121
CHAPTER 15 APPENDIX J ..................................................................................................... 122
Troubleshooting.............................................................................................................. 122
CHAPTER 16 APPENDIX K..................................................................................................... 126
Installing the USB driver ................................................................................................. 126

List of Figures
Figure 1. ADSL Network topology ...................................................................................................................................... 15
Figure 2. Web interface Status Page ................................................................................................................................. 17
Figure 3. Web interface User Management page .............................................................................................................. 18
Figure 4. Web interface Error Log page............................................................................................................................. 19
Figure 5. Save Configuration.............................................................................................................................................. 20
Figure 6. Configuration saved ............................................................................................................................................ 20
Figure 7. Web interface Restart page ................................................................................................................................ 21
Figure 8. ADSL Service Configuration ............................................................................................................................... 24
Figure 9. ATM parameters ................................................................................................................................................. 26
Figure 10. RFC1483 Bridged Connection .......................................................................................................................... 29
Figure 11. RFC1483 Routed Connection ........................................................................................................................... 30
Figure 12. IP over ATM Connection ................................................................................................................................... 31
Figure 13. PPP over ATM Bridged Connection.................................................................................................................. 32
Figure 14. PPP over ATM Routed Connection................................................................................................................... 33
Figure 15. PPPoE allows ISPs to monitor the volume of traffic that their users generate.................................................. 34
Figure 16. PPPoE on a Local Network............................................................................................................................... 35
Figure 17. PPP over Ethernet Routed Connection............................................................................................................. 35
Figure 18. IP packet or datagram....................................................................................................................................... 38
Figure 19. Subdivision of the 32 bits of an Internet address .............................................................................................. 40
Figure 20. How to change the LAN/USB IP Address ......................................................................................................... 43
Figure 21. How to add a new Static Route......................................................................................................................... 45
Figure 22. DHCP service web page ................................................................................................................................... 47
Figure 23. DHCP relay ....................................................................................................................................................... 48
Figure 24. DHCP relay setting............................................................................................................................................ 49
Figure 25. DHCP server ..................................................................................................................................................... 50
Figure 26. DHCP server settings........................................................................................................................................ 51
Figure 27. Domain Name System ...................................................................................................................................... 52
Figure 28. DNS relay settings ............................................................................................................................................ 53
Figure 29. Security configuration web page ....................................................................................................................... 57
Figure 30. Interfaces List.................................................................................................................................................... 58
Figure 31. Security level..................................................................................................................................................... 61
Figure 32. Low Security level ............................................................................................................................................. 61
Figure 33. Medium Security level ....................................................................................................................................... 62
Figure 34. High Security level ............................................................................................................................................ 62
Figure 35. Current Firewall Policies ................................................................................................................................... 63
Figure 36. Firewall Port Filters ........................................................................................................................................... 64
Figure 37. Adding a new TCP filter .................................................................................................................................... 64
Figure 38. Firewall configuration example.......................................................................................................................... 65
Figure 39. Firewall Add TCP port filters ............................................................................................................................. 66
Figure 40. TCP flows in FTP .............................................................................................................................................. 67
Figure 41. Dynamic port opening: connecting to an external RealServer.......................................................................... 71
Figure 42. New Dynamic port opening ............................................................................................................................... 71
Figure 43. Dynamic port opening configuration.................................................................................................................. 72
Figure 44. Dynamic Port Opening settings for Real Player Applications ........................................................................... 73
Figure 45. Dynamic port opening settings for Netmeeting applications ............................................................................. 75
Figure 46. Attack Detection and Blocking web page.......................................................................................................... 77
Figure 47. NAT configuration Web Page............................................................................................................................ 78
Figure 48. NAT enabling Web Page................................................................................................................................... 79
Figure 49. NAT related setting ........................................................................................................................................... 80
Figure 50. NAT services: ftp access from external............................................................................................................. 81
Figure 51. Reserved Mapping Configuration...................................................................................................................... 81
Figure 52. Reserved Mapping settings............................................................................................................................... 82

AT-AR240E ADSL Bridge/Router Web Interface User Manual 7
Figure 53. NAT services: ftp and http access from external............................................................................................... 83
Figure 54. NAT services: IPSec connection....................................................................................................................... 84
Figure 55. NAT services: using two public IP adresses ..................................................................................................... 85
Figure 56. Global Address Pool settings ............................................................................................................................ 86
Figure 57. AT-AR240E console login ................................................................................................................................. 90
Figure 58. AT-AR240E console.......................................................................................................................................... 90
Figure 59. AT-AR240E console – SNMP module .............................................................................................................. 91
Figure 60. How to close the console .................................................................................................................................. 92
Figure 61. SNMP commands online help........................................................................................................................... 93

List of Tables
Table 1: Protocols and standards supported by the AT-AR240E ADSL Bridge/Router. .................................................... 11
Table 2: Typographic conventions used in this manual. .................................................................................................... 13
Table 3: G.DMT features.................................................................................................................................................... 25
Table 4: G.Lite features...................................................................................................................................................... 25
Table 5: Functions of the fields in an IP datagram ............................................................................................................. 39
Table 6: Internet Protocol address classes and limits on numbers of networks and hosts. ............................................... 40

AT-AR240E ADSL Bridge/Router Web Interface User Manual 9
Preface
Purpose of this Manual
This manual is the complete reference for the AT-AR240E ADSL
Bridge/Router web interface that allows the user to initialise, view and
modify the router configuration in order to match the characteristics of the
related network environment. Using this web interface the user has the ability
to configure the following services:
 ADSL
 Security
 DHCP Client-Server/Relay
 DNS Client/Relay
 LAN and USB interfaces
 IP Routing
Using the web it is also possible to:
 Upload a new software
 Save the configuration
 Restart the router
 Check the system status
 View error log
 Define new users for management
 The AT-AR240E Console is provided to configure and show the status of the SNMP
module.
Intended Audience
This manual is intended for the system administrator, network manager or
communications technician who will configure and maintain the AT-AR240E.

It is assumed that the reader is familiar with:
 The topology of the network in which the AT-AR240E is to be used.
 Basic principles of computer networking, ADSL protocols, IP protocols
and routing, and interfaces.
 Administration and operation of a computer network.
 This manual is not intended for users who will use the computer network to
access network services from their terminal, personal computer or workstation.
 Most of the configurations described in this manual require
Administrator privilege.
Structure of this Manual
This manual is organised into the following chapters:
 Chapter 1, Overview introduces the AT-AR240E ADSL Bridge/Router, its
Web interface and the related network environment.
 Chapter 2, Configuring the ADSL interface gives an introduction to the ADSL
technology, describes the main concepts of an ATM network, its Quality of
Service parameters and all the protocols supported by the AT-AR240E to
establish an ADSL connection.
 Chapter 3, LAN-USB gives a brief introduction to the IP protocol and
describes how to configure the LAN - USB interfaces on the AT-AR240E. It
describes also how to add/modify/remove static routes within the router.
 Chapter 4, DHCP gives a brief introduction to the Dynamic Host
Configuration Protocol and describes how to configure the DHCP server/relay
services on the AT-AR240E
 Chapter 5, DNS gives an introduction to the Domain Name System and
describes how to configure the DNS client/relay services on the AT-AR240E
 Chapter 6, Security describes all the supported features concerning the
Firewall, the ‘‘Dynamic Port Opening’’, the ‘‘Attack Detection and Blocking’’
and the NAT services on the AT-AR240E
 Chapter 7, SNMP gives an introduction to the SNMP protocol and describes
how to access to the AT-AR240E Console for configuring the SNMP module

AT-AR240E ADSL Bridge/Router Web Interface User Manual 11
Standards and Protocols
Supported Standards and Protocols
Table 1 lists the protocols and standards supported by the AT-AR240E ADSL
Bridge/Router and the references where these protocols and standards are
defined.
Table 1: Protocols and standards supported by the AT-AR240E ADSL
Bridge/Router.
Protocol/standard
Reference
DHCP RFCs 1541, 1542.
Encapsulation over
ATM
RFC 1483
IP RFCs 791, 821, 950, 951, 1009, 1055, 1122, 1144,
1349, 1542, 1812, 1858.
IP addressing RFC 1597.
IP over ATM RFC 1577
PPP over ATM RFC 2364
PPP over Ethernet RFC 2516
SNMP, MIBs RFCs 1155, 1157, 1213, 1239, 1315, 1398, 1493, 1514,
1573, 2233.
Obtaining Copies of Internet Protocols and Standards
The Internet Protocols are defined in Requests For Comments (RFCs). RFCs are
developed and published under the auspices of the Internet Engineering
Steering Group (IESG) of the Internet Engineering Task Force (IETF). For more
information about the IESG and IETF, visit the IETF web site at
http://www.ietf.org/.
For more information about RFCs and Internet Drafts (the starting point for
RFCs), visit the RFC Editor web site at http://www.rfc-editor.org/.
This site has information about the RFC standards process, archives of RFCs
and current Internet Drafts, links to RFC indexes and search engines, and a
list of other RFC repositories.
RFCs can be obtained electronically from many RFC repositories, mail
servers, World Wide Web (WWW), Gopher or WAIS sites. A good starting
point for finding the nearest RFC repository is to point your Web browser at
http://www.isi.edu/in-notes/rfc-retrieval.txt.
To obtain a copy of an RFC using FTP, FTP to the host and login as user
anonymous, and a password of either guest or your email address. The FTP
server will usually prompt you for one or the other. Use the get command
to retrieve the desired RFC. Most sites have a file, usually rfc-index.txt,

which lists the titles and file names of all available RFCs. Most sites have a
file, usually rfc-retrieval.txt, which gives detailed information about
RFC repositories and how to retrieve RFCs via FTP, mail servers, WWW,
Gopher and WAIS.
To learn how to obtain a copy of an RFC via email from a mail server, point
your browser at http://www.isi.edu/in-notes/rfc-editor/rfc-
info.
To obtain a copy of an RFC from a Web site, or to search RFC repositories for
a specific RFC or all RFCs relating to a topic, point your Web browser at
http://www.rfc-editor.org/rfc.html.
Background Reading
For an introduction to the Internet Protocols refer to:
DDN Protocol Handbook, Elizabeth J. Feinler, 1991, DDN Network
Information Center, SRI International, 333 Ravenswood Avenue, Menlo
Park, CA 94025, USA. Email: [email protected]il.
Int e rnet w o r k ing w i t h T CP/ I P ------ Volume I: Principles, protocols and
architecture (2nd Edition), Douglas E. Comer, 1991, Prentice-Hall
International, Inc., New Jersey. ISBN 0-13-474321-0.
Int e rnet w o r k ing w i t h T C P / I P ------ Volume II: Design, implementation, and
internals, Douglas E. Comer and David L. Stevens, 1991, Prentice-Hall
International, Inc., New Jersey. ISBN 0-13-472242-6.
Int e rnet w o r k ing w i t h T C P / I P ------ Volume III: Client-server programming and
applications, Douglas E. Comer and David L. Stevens, 1993, Prentice-
Hall International, Inc., New Jersey. ISBN 0-13-474222-2.
For a description of layered protocols refer to:
Computer networks (2nd Edition), Andrew S. Tanenbaum, 1989, Prentice-
Hall International, Inc., New Jersey. ISBN 0-13-162959-0.
For an introduction to network management refer to:
The si m p l e boo k ------ An introduction to management of TCP/IP-based
Internets, Marshall T. Rose, 1991, Prentice-Hall International, Inc. ISBN
013812611-9.
For an introduction to ADSL refer to:
ADSL: Standards, Implementation and Architecture, Charles K. Summers,
CRC Press Advanced and Emerging Communication Technologies
Series CRC Press; ISBN: 084939595X; (June 1999).

AT-AR240E ADSL Bridge/Router Web Interface User Manual 13
For an introduction to PPP refer to:
Using and Managing PPP, Andrew Sun, O’Reilly; ISBN: 1565923219;
(March 1999).
Publicly Accessible Documents
Allied Telesyn maintains an online archive of documents and files that
customers can access via the World Wide Web or via anonymous FTP. For
WWW access, point your Web browser at
http://www.alliedtelesyn.com.
Conventions
A number of symbols, typographic and stylist conventions are used
throughout this manual to aid learning and make information easier to find
(Table 2).
Table 2: Typographic conventions used in this manual.
This typeface
Is used for
Italic Referring to another section in this manual or another
manual, or to introduce and emphasise new terms. For
example, “See Chapter 2, ADSL”.
Monospace Text as it appears on-screen, or anything you must type.
0xFF Numbers starting with the 0x prefix are hexadecimal
values.
Attention A special keystroke known as the attention character,
which will be either [Break] or [Ctrl/P].
 Note. A note like this presents additional information or interesting sidelights.
Warning. A warning alerts you to situations in which you could do something that
might result in a loss of data, or cause damage to the equipment.

Chapter 1 - Overview
14
Chapter 1
Overview
Introduction
Overview of the AT-AR240E ADSL Bridge/Router
The AT-AR240E ADSL Bridge/Router provides data access for multiple users
in Small Office/Home Office (SOHO), Small to Medium Enterprise (SME) or
Branch Offices wanting very fast download speeds or who need to combine
broadband access with a telephone service (see Figure 1).
ADSL, a high bit rate digital subscriber line access technology, provides
asymmetrical data over a single pair of local loop copper. Users can access the
Internet, corporate LAN or Video on Demand services, downloading at
speeds up to 8Mbps and uploading data at speeds of up to 1Mbps.
The AT-AR240E ADSL Bridge/Router implements the ITU standards G.992.1
(G.DMT), G.922.2 (G.lite) and ANSI (T1.413) for operation over mixed gauge
two-wire circuits and is interoperable with all major DSLAM and Multi
Service Access Systems. When used with a POT’s Splitter the AT-AR240E
ADSL Bridge/Router can be used in conjunction with a telephony service
using the same two-wire local loop circuit.
Affordable broadband access is provided without compromising
performance, security or routing capability.
The Router provides a 10Mbps Ethernet and a USB Interface for connection to
the office LAN and it supports automatic assignment of IP addresses to
personal computers via a built-in Dynamic Host Configuration Protocol
(DHCP) server.

AT-AR240E ADSL Bridge/Router Web Interface User Manual 15
Figure 1. ADSL Network topology
An advanced Security system provides the following services (see Chapter 6 for
details):
• Firewall
• Dynamic Port Opening
• Attack Detection and Blocking
• Advanced Network Address Translation (NAT)
Customers using the AT-AR240E ADSL Bridge/Router may decide to create
up to four independent routed ADSL connections (each with full routing
capability and selectable QoS parameters) or one Bridged ADSL connection.
IP address assignment can be either static or dynamic per virtual ATM
connection.
How to start the web interface
To run the AT-AR240E web interface, ensure that your Web Browser is
Microsoft® Internet Explorer 5.0 (or later) and disable any proxy settings on
your Web Browser as follows:

Chapter 1 - Overview
16
 Steps may vary, depending on the Browser version.
• Double-click on the Internet Explorer icon.
• Click Tools > Internet Options.
• Select the “Connections” tab.
• Click on the LAN Settings button. Ensure that the use of Proxy Server
is disabled.
• Click OK for changes to take effect.
The default IP address on the AT-AR240E is 192.168.1.1.
The IP address on your PC has to be in the same subnet as 192.168.1.1. It is
outside the scope of this manual to explain how to achieve this setting on
your PC.
After connecting to the default IP address http://192.168.1.1:8080 the Web
interface will ask for the username and password to access the system.
Default settings for these parameters are:
Username: manager
Password: friend

AT-AR240E ADSL Bridge/Router Web Interface User Manual 17
Performing Basic Tasks
Status
The AT-AR240E has three physical ports: the ADSL, the LAN and the USB.
Using the Web interface, clicking on STATUS it is possible to check the status
of each port.
As shown in Figure 2, each physical port has an associated virtual LED
indicating the presence of the related physical link. A GREEN virtual LED
indicates the presence of the link; otherwise a RED virtual LED is shown.
The STATUS web page also provides some useful statistics on all the created
ADSL connections (see Chapter 2 for details); it is also possible to check the
status of both the LAN and the USB interfaces.
The STATUS web page provides a view on the AT-AR240E Security system
through the following buttons: ---- ʹFirewall', ʹDynamic Port
Openingʹ, ʹAttack Detection and Blockingʹand 'NAT' (see Chapter
6 for details).
Figure 2. Web interface Status Page

Chapter 1 - Overview
18
User Management
Clicking on ʹUsers Managementʹenables the definition of new users. Two
kind of users are defined (see Figure 3):
 Normal User
 Administrator
 A normal user is only able to view and check the status of the ADSL router without
having any configuration privileges.
To add or modify a User the following parameters have to be added:
• Username: a string with a length in the range [1,60]
• Password : a string with a length in the range [1,60]
• Permission: two choices are available: User or Administrator
• Comment: a max 60 chars string
Figure 3. Web interface User Management page

AT-AR240E ADSL Bridge/Router Web Interface User Manual 19
Error Log
Clicking on ʹError Logʹdisplays a table as shown in Figure 4.
This table shows some useful information on configuration errors:
• When: time in seconds since last reboot
• Process: the process that caused the error
• Error: the error description
Figure 4. Web interface Error Log page

Chapter 1 - Overview
20
Save Configuration
The ʹSave Configurationʹsection provides the opportunity to store into
the internal flash all the configuration settings made by the AT-AR240E
administrator (see Figure 5).
Figure 5. Save Configuration
There will be a delay (approximately 15 secs) for saving the configuration.
After the configuration has been saved the following web page will appear:
Figure 6. Configuration saved