Manual AVM ISDN MultiProtocol Router for Windows 2000 ADSL (page 57 of 134) (English)

559563

Zoom out

Zoom in

1/134

Filters and Rules

55 NT/MPRI – 4 Special NT/MPRI Settings

– Reject: the packet is not sent on. The error message “Destina-

tion not reachable” is sent back to the source address.

Each packet is compared with the criteria of each rule in succession un-

til the first rule is found which applies to it. If the applicable action is

“Deny” or “Reject” the filtering process for this packet is concluded.

If no rule applying to this packet is found, or if the default action is “Ac-

cept”, the packet is sent on to the next filter instance.

Bear in mind the two following aspects when creating a filter:

l A filter profile always handles all packets (the rules apply to cer-

tain packets and the default action to all others).

l The sequence of the rules is extermely important! It is essential

that more general rules be placed toward the bottom of the pro-

file. Otherwise, more specific rules that are located lower down in

the hierarchy would never be applied.

The basic principle should be applied when designing a filter profile:

handle minority cases first.

A simple example: Suppose only call destination A is to be granted ac-

cess to computer B in the LAN. To set this condition, define the follow-

ing two rules in the global input filter:

1. A is granted access to computer B. Thus the first rule states: ac-

cept packets for all services which have the IP range of A as the

source and B’s IP address as the destination.

2. No one (i.e., no one else) is permitted access to the computer.

Thus the second rule states: deny packets for all services which

have any IP address and are addressed to the IP address of B.

The illustrations below show the order in which the filter instances are

applied for incoming and outgoing packets and those forwarded over

ISDN to another network. It is assumed that all filter instances are en-

abled and that the applicable or default rule for the packet in the exam-

ple is “Accept” so that the longest possible packet path is illustrated:

ntmpri-e.book Seite 55 Donnerstag, 28. Februar 2002 11:26 11

Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

Forumrules

To achieve meaningful questions, we apply the following rules:

First, read the manual;
Check if your question has been asked previously;
Try to ask your question as clearly as possible;
Did you already try to solve the problem? Please mention this;
Is your problem solved by a visitor then let him/her know in this forum;
To give a response to a question or answer, do not use this form but click on the button 'reply to this question';
Your question will be posted here and emailed to our subscribers. Therefore, avoid filling in personal details.

new questions and answers
new manuals

You will receive an email to register for one or both of the options.

Get your user manual by e-mail

Enter your email address to receive the manual of AVM ISDN MultiProtocol Router for Windows 2000 ADSL in the language / languages: English as an attachment in your email.

The manual is 3,51 mb in size.

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.

Info

AVM ISDN MultiProtocol Router for Windows 2000 ADSL Manual

Product: