ZyXEL Communications P-661HNU-FX Manual

P-661HNU Series Support Notes
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All contents copyright © 2010 ZyXEL Communications Corporation.
P-661HNU-Fx
802.11n Wireless ADSL2+ 4-port Security Gateway
Support Notes
Version3.10
Oct 2010

P-661HNU Series Support Notes
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All contents copyright © 2010 ZyXEL Communications Corporation.
FAQ.....................................................................................................................................6
ZLD FAQ.........................................................................................................6
1. What is ZLD?..........................................................................................6
2. What‟s Multilingual Embedded Web Configurator? .........................6
3. How do I update the firmware and configuration file?.....................6
4. What should I do if I forget the system password?..........................6
5. How to use the Reset button?.............................................................6
6. Is it possible to access a server running behind SUA from the
outside Internet? How can I do it?..........................................................7
7. Is there any troubleshooting method on ZLD platform? .................7
Product FAQ ..................................................................................................8
1. How can I manage P-661HNU-Fx?......................................................8
2. What is the default password for Web Configurator? .....................8
3. What‟s the difference between „Common User Account‟ and
„Administrator Account‟? .........................................................................8
4. Will the device work with my Internet connection? .........................8
5. How do I know the P-661HNU-Fx's WAN IP address assigned by
the ISP?.......................................................................................................9
6. What is the micro filter or splitter used for? .....................................9
7. The P-661HNU-Fx supports Bridge and Router mode, what's the
difference between them?........................................................................9
8. How do I know I am using PPPoE?.....................................................9
9. Why does my provider use PPPoE?...................................................9
10. What is NAT? ..................................................................................... 10
11. How NAT works?...............................................................................10
12. What is DDNS? ..................................................................................11
13. When do I need DDNS service? ...................................................... 11
14. What is DDNS wildcard? Does the P-661HNU-Fx support DDNS
wildcard?.................................................................................................. 12
15. What is Traffic Shaping?..................................................................12
16. Why do we perform traffic shaping in the P-661HNU-Fx?........... 12
17. What do the parameters (PCR, SCR, MBS) mean?....................... 12
18. What do the ATM QoS Types (CBR, UBR, VBR-nRT, VBR-RT)
mean? .......................................................................................................13
ADSL FAQ ....................................................................................................14
1. How does ADSL compare to Cable modems?................................ 14
2. What is the expected throughput? ...................................................14
3. What is the microfilter used for? ...................................................... 14
4. How do I know the ADSL line is up? ................................................14
5. How does the P-661HNU-Fx work on a noisy ADSL? .................... 14

P-661HNU Series Support Notes
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6. Does the VC-based multiplexing perform better than the
LLC-based multiplexing?.......................................................................15
7. How do I know the details of my ADSL line statistics? .................15
8. What are the signaling pins of the ADSL connector?....................15
9. What is triple play? .............................................................................15
Firewall FAQ ................................................................................................17
General......................................................................................................17
1. What is a network firewall? ....................................................17
2. What makes P-661HNU-Fx secure? .....................................17
3. What are the basic types of firewalls?...................................17
4. What kind of firewall is the P-661HNU-Fx?...........................18
5. Why do you need afirewall when your router has NAT built-in?
.....................................................................................................18
6. What is Denials of Service (DoS) attack?..............................18
7. What is Ping of Death attack?................................................19
8. What is Teardrop attack?.......................................................19
9. What is SYN Flood attack? ....................................................19
10. What is LAND attack?..........................................................19
11 What is Brute-force attack?...................................................19
12. What is IP Spoofing attack?.................................................20
13. What are the default firewall rules in P-661HNU-Fx?.........20
Configuration...........................................................................................20
1. How do I configure the firewall?.............................................20
2. How do I prevent others from configuring my firewall?.........20
3. Why can't I configure my P-661HNU-Fx using Web
Configurator/Telnet over WAN?.................................................21
4. Whycan't I upload the firmware and configuration file using
FTP over WAN?..........................................................................22
Wireless FAQ...............................................................................................23
General FAQ............................................................................................. 23
1. What is a Wireless LAN?.....................................................23
2. What are the advantages of Wireless LAN? .....................23
3. What is the disadvantage of Wireless LAN? ....................23
4. Where can you find 802.11 wireless networks?...............24
5. What is an Access Point? ...................................................24
6. Is it possible to use wireless products from a variety of
vendors?....................................................................................24
7. What is Wi-Fi?.......................................................................24
8. What types of devices use the 2.4GHz Band? .................24
9. Does the 802.11 interfere with Bluetooth device?...........25
10. Can radio signals pass through wall?.............................25
11. What are potential factors that may causes interference
among WLAN products?.........................................................25
12. What's the difference between a WLAN and a WWAN? 26

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13. Can I manually swap the wireless module without
damage any hardware? ...........................................................26
14. What wireless security mode does P-661HNU-Fx support?
.....................................................................................................26
15. What Wireless standard does P-661HNU-Fx support? .26
16. Does P-661HNU-Fx support MAC filtering?....................26
17. Does P-661HNU-Fx support auto rate adaption?...........26
Advanced FAQ.........................................................................................27
1. What is Ad Hoc mode?........................................................27
2. What is Infrastructure mode?.............................................27
3. How many Access Points are required in a given area? 27
4. What is Direct-Sequence Spread Spectrum Technology –
(DSSS)?......................................................................................27
5. What is Frequency-hopping Spread Spectrum Technology
–(FHSS)?...................................................................................27
Security FAQ............................................................................................28
1. How do I secure the data across the P-661HNU-Fx Access
Point's radio link?.....................................................................28
2. What is WEP?........................................................................28
3. What is WPA-PSK? ..............................................................29
4. What is the difference between 40-bit and 64-bit WEP?.29
5. What is a WEP key? .............................................................29
6. Will 128-bit WEP communicate with 64-bit WEP? ...........29
7. Can the SSID be encrypted?...............................................29
8. By turning off the broadcast of SSID, can someone still
sniff the SSID? ..........................................................................29
9. What are Insertion Attacks? ...............................................30
10. What is Wireless Sniffer?..................................................30
Application Notes........................................................................................ 31
General Application Notes.....................................................................31
1. Internet Access Using P-661HNU-Fx under Bridge mode....31
2. Internet Access Using P-661HNU-Fx under Routing mode..35
3. Internet Access Using 3G Backup.........................................37
4. SUA Notes ..............................................................................40
5. Using the Dynamic DNS (DDNS)...........................................49
6. File Sharing.............................................................................50
7. QoS.........................................................................................57
8. Using syslog ...........................................................................60
9. Using IP Multicast...................................................................61
Wireless Application Notes....................................................................62
1. Configure a Wireless Client to Ad hoc mode.........................62
2. Setup WEP (Wired Equivalent Privacy).................................66
3. Site Survey..............................................................................70
4. WPS application .....................................................................73

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5. Configure 802.1x and WPA....................................................74
6. The WPS/WLAN Button.........................................................78
Support Tool................................................................................................79
1. Upgrading Firmware via web GUI .....................................................79
2. Backing –up the Configuration ........................................................79
3. Upload Configuration via web GUI ...................................................81
4. Using FTP to Upload the Firmware and Configuration Files ........82
Using Windows command.........................................................................83

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All contents copyright © 2010 ZyXEL Communications Corporation.
FAQ
ZLD FAQ
1. What is ZLD?
ZLD is ZyXEL Linux Distribution. It is the Linux based platform abbsorted free
and open source software on our routers that delivers network services and
applications. It is designed in a modular fashion so it is easy for developers to
add new features.
2. What‟sMultilingual Embedded Web Configurator?
Multilinggual Embedded Web Configurator means that it can display with 4
kinds of languanges: English, Turkish, German and French. By factory default
it displays with English, and you can change it in Web GUI.
3. How do I update the firmware and configuration file?
You can do this if you access the P-661HNU-Fx as Administrator. You can
upload the firmware and configuration file to Prestige from Web Configurator,
or using FTP or TFTP client software. You CAN NOT upload the firmware and
configuration file via Telnet because the Telnet connection will be dropped
during uploading the firmware. Please do not power off the router right after the
FTP or TFTP uploading is finished, the router will upload the firmware to its
flash at this moment.
Note: There may be firmware that could not be upgraded from Web
Configurator. In this case, ZyXEL will prepare special Upload Software
for you. Please read the firmware release note carefully when you want to
upload a new fireware.
4. What should I do if I forget the system password?
In case you forget the system password, you can erase the current
configuration and restore factory defaults this way:
Use the RESET button on the rear panel of P-661HNU-Fx to reset the router.
After the router is reset, the LAN IP address will be reset to '192.168.1.1', the
common user account will be reset to 'user/1234', the Administrator account
will be reset to „admin/1234‟.
5. How to use the Reset button?
a. Turn your P-661HNU-Fx on. Make sure the POWER led is on (not
blinking)

P-661HNU Series Support Notes
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b. Press the RESET button for longer than one second and shorter than
five seconds and release it.
c. Press the RESET button for six seconds and then release it. If the
POWER LED begins to blink, the default configuration has been
restored and the P-661HNU-Fx restarts.
6. Is it possible to access a server running behind SUA from the outside
Internet? How can I do it?
Yes, it is possible because P-661HNU-Fx delivers the packet to the local
server by looking up to a SUA server table. Therefore, to make a local server
accessible to the outside users, the port number and the inside IP address of
the server must be configured. (You can configure it in Web Configurator,
Advanced Setup, Network Setting -> NAT -> Port Forwarding.
7. Is there any troubleshooting method on ZLD platform?
You could mirror WAN packet to LAN host
Telnet into the device, triggle command „/var/trafficmirror.sh nas 1 192.168.1.x‟
Note: It is protected by super username & password, „root/1234‟by
factory default.
Make sure your PC which is used to capture WAN packets has been set with a
static ip 192.168.1.x in case the PC will be allocated another IP after DHCP
lease time.

P-661HNU Series Support Notes
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All contents copyright © 2010 ZyXEL Communications Corporation.
Product FAQ
1. How can I manage P-661HNU-Fx?
Multilingual Embedded Web GUI for Local and Remote management
Telnet support („root/1234‟Protected ) for remote configuration change
and status monitoring
FTP sever, firmware upgrade and configuration backup and restore are
supported(„admin/1234‟Protected)
2. What is the default password for Web Configurator?
There are two different accounts for P-661HNU-Fx Web Configurator:
Common User Account and Administrator Account.
By factory default the password for the two accounts are:
Common User Account: user/1234
Administrator Account: admin/1234.
You can change the password after you logging in the Web Configurator.
Please record your new password whenever you change it. The system
will lock you out if you have forgotten your password.
3. What‟s the difference between „Common User Account‟and
„Administrator Account‟?
For Common User Account, it can just change the password of common user
but can‟t change the password of Administrator.
For Administrator Account, it can change both Administrator Account‟s
password and Common User Account‟s password.
Moreover, to manage the P-661HNU-Fx via Telnet, you should use another
account „root/1234‟.
4. Will the device work with my Internet connection?
P-661HNU-Fx is designed to be compatible with major ISPs utilize ADSL as a
broadband service. P-661HNU-Fx offers Ethernet ports to connect to your
somputer so the device is placed in the line between the computer and your
ISP. If your ISP supports PPPoE you can also use the device, because PPPoE
is supported in the device.

P-661HNU Series Support Notes
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All contents copyright © 2010 ZyXEL Communications Corporation.
5. How do I know the P-661HNU-Fx's WAN IP address assigned by the
ISP?
You can view "- IP Address : x.x.x.x" shown in Web Configurator „Connection
Status -> System Info -> Device Information -> WAN 1 Information‟to check
this IP address.
6. What is the micro filter or splitter used for?
Generally, the voice band uses the lower frequency ranging from 0 to 4KHz,
while ADSL data transmission uses the higher frequency. The micro filter acts
as a low-pass filter for your telephone set to ensure that ADSL transmissions
do not interfere with your voice transmissions. For the details about how to
connect the micro filter please refer to the user's manual.
7. The P-661HNU-Fx supports Bridge and Router mode, what's the
difference between them?
When the ISP limits some specific computers to access Internet, that means
only the traffic to/from these computers will be forwarded and the other will be
filtered. In this case, we use bridge mode which works as an ADSL modem to
connect to the ISP. The ISP will generally give one Internet account and limit
only one computer to access the Internet.
For most Internet users having multiple computers want to share an Internet
account for Internet access, they have to add another Internet sharing device,
like a router. In this case, we use the router mode which works as a general
Router plus an ADSL Modem.
8. How do I know I am using PPPoE?
PPPoE requires a user account to login to the provider's server. If you need to
configure a user name and password on your computer to connect to the ISP
you are probably using PPPoE. If you are simply connected to the Internet
when you turn on your computer, you probably are not. You can also check
your ISP or the information sheet given by the ISP. Please choose PPPoE as
the encapsulation type in the P-661HNU-Fx if the ISP uses PPPoE.
9. Why does my provider use PPPoE?
PPPoE emulates a familiar Dial-Up connection. It allows your ISP to provide
services using their existing network configuration over the broadband
connections. Besides, PPPoE supports a broad range of existing applications

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All contents copyright © 2010 ZyXEL Communications Corporation.
and service including authentication, accounting, secure access and
configuration management.
10. What is NAT?
The NAT (Network Address Translation-NAT RFC 1631) is the translation of
an Internet Protocol address used within one network to a different IP address
known within another network. One network is designated as the inside
network and the other is the outside. Typically, one company maps its local
inside network addresses to one or more global outsile IP addresses and
“unmaps”the global IP addresses on the incoming packets back into local IP
addresses. The IP addresses for NAT can be either fixed or dynamically
assigned by the ISP. In addition, you can designate servers, e.g., a Web
server and a Telnet server, on your local network and make them accessible to
the outside world. If you do not define any servers, the NAT offers the
additional benefit of firewall protection. In such case, all incoming connections
to your network will be filtered out by the CPE, thus preventing intruders from
probing your network.
For more information on the IP address translation, please refer to RFC 1631,
The IP Network Address Translator (NAT).
11. How NAT works?
If we define the local IP addressed as the Internal Local Addresses (ILA) and
the global IP addresses as the Inside Gloable Address (IGA), see the following
figure. The term „inside‟refers to the set of networks that are subject to
translation. The NAT operates by mapping the ILA to the IGA required for
communication with hosts on other networks. It replaces the original IP source
address (and TCP or UDP source port numbers) and then forwards each
packet to the Internet ISP, thus making them appear as if they came from the
NAT system itself (e.f., the PCE router). The CPE keeps track of the original
addresses and port numbers, so the incoming reply packets can have their
original values restored.