Classless Inter-Domain Routing (CIDR)
Classless Inter-Domain Routing (CIDR)
- April 23, 2021
- Posted by: Nicola Selenu

method for allocating IP addresses and for IP routing. The IETF introduced CIDR in 1993 to replace the previous classful network addressing Internet architecture. CIDR’s goal is slow the growth of routing tables on routers across the Internet and to help slow the exhaustion of IPv4 addresses.
We host a free tool to calculate the IP Range in a CIDR.
Author:Nicola Selenu
Email Service Providers Handbook
The most comprehensive “Handbook of Email Service Providers“!
SPAMASSASSIN RULES
All SpamAssassin rules in one place, EXPLAINED!
SMTP COMMANDS
& REPLY CODES
All SMTP/ESMTP commands and reply codes in one place, EXPLAINED!
Free DNS Tool
Check the DNS records of your domain with our free DNS tool.
Deliverability Glossary
The most comprehensive Email Deliverability and Marketing Glossary!
Classless Inter-Domain Routing (CIDR)
method for allocating IP addresses and for IP routing. The IETF introduced CIDR in 1993 to replace the previous classful network addressing Internet architecture. CIDR’s goal is slow the growth of routing tables on routers across the Internet and to help slow the exhaustion of IPv4 addresses.
We host a free tool to calculate the IP Range in a CIDR.
« Back to Glossary IndexAuthor:Nicola Selenu
Email Service Providers Handbook
The most comprehensive “Handbook of Email Service Providers“!
SPAMASSASSIN RULES
All SpamAssassin rules in one place, EXPLAINED!
SMTP COMMANDS
& REPLY CODES
All SMTP/ESMTP commands and reply codes in one place, EXPLAINED!
Free DNS Tool
Check the DNS records of your domain with our free DNS tool.
Deliverability Glossary
The most comprehensive Email Deliverability and Marketing Glossary!
« Back to Glossary Index