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Appendix DIP Addresses and Subnetting

The following table is a summary for subnet planning on a network with a 16-bit
network number.

Table 72 16-bit Network Number Subnet Planning

NO. #BORROWED$
HOST BITS

1 255.255.128.0 (/17) 2 32766

2 255.255.192.0 (/18) 4 16382

3 255.255.224.0 (/19) 8 8190

4 255.255.240.0 (/20) 16 4094

5 255.255.248.0 (/21) 32 2046

6 255.255.252.0 (/22) 64 1022

7 255.255.254.0 (/23) 128 510

8 255.255.255.0 (/24) 256 254

9 255.255.255.128 (/25) 512 126

10 255.255.255.192 (/26) 1024 62

11 255.255.255.224 (/27) 2048 30

12 255.255.255.240 (/28) 4096 14

13 255.255.255.248 (/29) 8192 6

14 255.255.255.252 (/30) 16384 2

15 255.255.255.254 (/31) 32768 1

SUBNET MASK NO. SUBNETS

NO. HOSTS PER
SUBNET

Configuring IP Addresses

Where you obtain your network number depends on your particular situation. If
the ISP or your network administrator assigns you a block of registered IP
addresses, follow their instructions in selecting the IP addresses and the subnet
mask.

If the ISP did not explicitly give you an IP network number, then most likely you
have a single user account and the ISP will assign you a dynamic IP address when
the connection is established. If this is the case, it is recommended that you select
a network number from 192.168.0.0 to 192.168.255.0. The Internet Assigned
Number Authority (IANA) reserved this block of addresses specifically for private
use; please do not use any other number unless you are told otherwise. You must
also enable Network Address Translation (NAT) on the WiMAX Device.

Once you have decided on the network number, pick an IP address for your WiMAX
Device that is easy to remember (for instance, 192.168.1.1) but make sure that
no other device on your network is using that IP address.

The subnet mask specifies the network number portion of an IP address. Your
WiMAX Device will compute the subnet mask automatically based on the IP

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address that you entered. You don't need to change the subnet mask computed by
the WiMAX Device unless you are instructed to do otherwise.

Private IP Addresses

Every machine on the Internet must have a unique address. If your networks are
isolated from the Internet (running only between two branch offices, for example)
you can assign any IP addresses to the hosts without problems. However, the
Internet Assigned Numbers Authority (IANA) has reserved the following three
blocks of IP addresses specifically for private networks:

! 10.0.0.0 * 10.255.255.255

! 172.16.0.0 * 172.31.255.255

! 192.168.0.0 * 192.168.255.255

You can obtain your IP address from the IANA, from an ISP, or it can be assigned
from a private network. If you belong to a small organization and your Internet
access is through an ISP, the ISP can provide you with the Internet addresses for
your local networks. On the other hand, if you are part of a much larger
organization, you should consult your network administrator for the appropriate IP
addresses.

Regardless of your particular situation, do not create an arbitrary IP address;
always follow the guidelines above. For more information on address assignment,
please refer to RFC 1597, Address Allocation for Private Internets and RFC 1466,
Guidelines for Management of IP Address Space.

IP Address Conflicts

Each device on a network must have a unique IP address. Devices with duplicate
IP addresses on the same network will not be able to access the Internet or other
resources. The devices may also be unreachable through the network.

Conflicting Computer IP Addresses Example

More than one device can not use the same IP address. In the following example
computer A has a static (or fixed) IP address that is the same as the IP address
that a DHCP server assigns to computer B which is a DHCP client. Neither can
access the Internet. This problem can be solved by assigning a different static IP

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address to computer A or setting computer A to obtain an IP address
automatically.

Figure 122 Conflicting Computer IP Addresses Example

Conflicting Router IP Addresses Example

Since a router connects different networks, it must have interfaces using different
network numbers. For example, if a router is set between a LAN and the Internet
(WAN), the router s LAN and WAN addresses must be on different subnets. In the
following example, the LAN and WAN are on the same subnet. The LAN computers
cannot access the Internet because the router cannot route between networks.

Appendix DIP Addresses and Subnetting

Figure 123 Conflicting Computer IP Addresses Example

Conflicting Computer and Router IP Addresses Example

More than one device can not use the same IP address. In the following example,
the computer and the router s LAN port both use 192.168.1.1 as the IP address.

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The computer cannot access the Internet. This problem can be solved by
assigning a different IP address to the computer or the router s LAN port.

Figure 124 Conflicting Computer and Router IP Addresses Example

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APPENDIX E

Importing Certificates

This appendix shows you how to import public key certificates into your web
browser.

Public key certificates are used by web browsers to ensure that a secure web site
is legitimate. When a certificate authority such as VeriSign, Comodo, or Network
Solutions, to name a few, receives a certificate request from a website operator,
they confirm that the web domain and contact information in the request match
those on public record with a domain name registrar. If they match, then the
certificate is issued to the website operator, who then places it on the site to be
issued to all visiting web browsers to let them know that the site is legitimate.

Many ZyXEL products, such as the NSA-2401, issue their own public key
certificates. These can be used by web browsers on a LAN or WAN to verify that
they are in fact connecting to the legitimate device and not one masquerading as
it. However, because the certificates were not issued by one of the several
organizations officially recognized by the most common web browsers, you will
need to import the ZyXEL-created certificate into your web browser and flag that
certificate as a trusted authority.

Note: You can see if you are browsing on a secure website if the URL in your web

browser s address bar begins with https:// or there is a sealed padlock
icon () somewhere in the main browser window (not all browsers show the
padlock in the same location.)

In this appendix, you can import a public key certificate for:

! Internet Explorer on page 206

! Firefox on page 216

! Opera on page 222

! Konqueror on page 230

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Internet Explorer

The following example uses Microsoft Internet Explorer 7 on Windows XP
Professional; however, they can also apply to Internet Explorer on Windows Vista.

1 If your device s web configurator is set to use SSL certification, then the first time

you browse to it you are presented with a certification error.

Figure 125 Internet Explorer 7: Certification Error

2 Click Continue to this website (not recommended).

Figure 126 Internet Explorer 7: Certification Error

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Appendix EImporting Certificates

3 In the Address Bar, click Certificate Error > View certificates.

Figure 127 Internet Explorer 7: Certificate Error

4 In the Certificate dialog box, click Install Certificate.

Figure 128 Internet Explorer 7: Certificate

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5 In the Certificate Import Wizard, click Next.

Figure 129 Internet Explorer 7: Certificate Import Wizard

6 If you want Internet Explorer to Automatically select certificate store based

on the type of certificate, click Next again and then go to step 9.

Figure 130 Internet Explorer 7: Certificate Import Wizard

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Appendix EImporting Certificates

7 Otherwise, select Place all certificates in the following store and then click

Browse.

Figure 131 Internet Explorer 7: Certificate Import Wizard

8 In the Select Certificate Store dialog box, choose a location in which to save the

certificate and then click OK.

Figure 132 Internet Explorer 7: Select Certificate Store

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9 In the Completing the Certificate Import Wizard screen, click Finish.

Figure 133 Internet Explorer 7: Certificate Import Wizard

10 If you are presented with another Security Warning, click Yes.

Figure 134 Internet Explorer 7: Security Warning

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Appendix EImporting Certificates

11 Finally, click OK when presented with the successful certificate installation

message.

Figure 135 Internet Explorer 7: Certificate Import Wizard

12 The next time you start Internet Explorer and go to a ZyXEL web configurator

page, a sealed padlock icon appears in the address bar. Click it to view the page s
Website Identification information.

Figure 136 Internet Explorer 7: Website Identification

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Installing a Stand-Alone Certificate File in Internet Explorer

Rather than browsing to a ZyXEL web configurator and installing a public key
certificate when prompted, you can install a stand-alone certificate file if one has
been issued to you.

1 Double-click the public key certificate file.

Figure 137 Internet Explorer 7: Public Key Certificate File

2 In the security warning dialog box, click Open.

Figure 138 Internet Explorer 7: Open File - Security Warning

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3 Refer to steps 4-12 in the Internet Explorer procedure beginning on page206 to

complete the installation process.

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Removing a Certificate in Internet Explorer

This section shows you how to remove a public key certificate in Internet Explorer

7.

1 Open Internet Explorer and click TOOLS > Internet Options.

Figure 139 Internet Explorer 7: Tools Menu

Appendix EImporting Certificates

2 In the Internet Options dialog box, click Content > Certificates.

Figure 140 Internet Explorer 7: Internet Options

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3 In the Certificates dialog box, click the Trusted Root Certificates Authorities

tab, select the certificate that you want to delete, and then click Remove.

Figure 141 Internet Explorer 7: Certificates

4 In the Certificates confirmation, click Yes.

Figure 142 Internet Explorer 7: Certificates

5 In the Root Certificate Store dialog box, click Yes.

Figure 143 Internet Explorer 7: Root Certificate Store

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Appendix EImporting Certificates

6 The next time you go to the web site that issued the public key certificate you just

removed, a certification error appears.

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