Exim how to format to catch a list of IPs

[martin MHC]

On the Exim ByPass IP addresses for Sender Verify Callout there is an ability to list IPs to be except from the check.

The list states in its documentation:

You can use the following formats:

• Single IP addresses — Example: 192.168.0.1
• A range of IP addresses — Example: 192.168.0.0/24

But I don't understand this formatting -- I need to exempt a whole block of IPs that begin with 123.456.***.*** so any IP that starts with 123.456. should be exempted. How can I put this into the IP List in Exim using the above formatting?

Exim Version 4.95


For example;

I need to permit;

123.456.123.45
123.456.987.65
123.456.76.543
...
...
123.456.12.456

How can I construct this rule with one line on the above?

 

[martin MHC]

About Slash Notation

Many things use slash notation, also known as CIDR (Classless Inter-Domain Routing) notation, for many purposes, such as policy configuration. You use slash notation differently for IPv4 and IPv6 addresses.

IPv4

Slash notation is a compact way to show or write an IPv4 subnet mask. When you use slash notation, you write the IP address, a forward slash (/), and the subnet mask number.


To find the subnet mask number:

Convert the decimal representation of the subnet mask to a binary representation.
Count each “1” in the subnet mask. The total is the subnet mask number.


For example, to write the IPv4 address 192.168.42.23 with a subnet mask of 255.255.255.0 in slash notation:

Convert the subnet mask to binary.<br>
In this example, the binary representation of 255.255.255.0 is:<Br>
11111111.11111111.11111111.00000000.<Br>
Count each 1 in the subnet mask.<br>
In this example, there are twenty-four (24).<br>
Write the original IP address, a forward slash (/), and then the number from Step 2.<br>
The result is 192.168.42.23/24.<br>

This table shows common network masks and their equivalents in slash notation.

Network Mask Slash Equivalent
255.0.0.0 /8
255.255.0.0 /16
255.255.255.0 /24
255.255.255.128 /25
255.255.255.192 /26
255.255.255.224 /27
255.255.255.240 /28
255.255.255.248 /29
255.255.255.252 /30
255.255.255.254 /31
255.255.255.255 /32

 

[cPRex]

Hey there! You'd need to use a /16 for that CIDR class, so you'd use 123.456.0.0/16 to catch that entire range.