CIDR

networking

Classless Inter-Domain Routing — a method for allocating IP addresses and routing that replaced the classful network design.

Pronunciation

Correct

SY-dur

/ˈsaɪdər/

Pronounced as a single word 'SY-dur', rhyming with 'cider'. This is the widely accepted pronunciation in networking circles.

Source: www.rfc-editor.org(official spec)

Accepted Variant

C-I-D-R

/siːaɪdiːɑːr/

Some engineers spell it out as individual letters, though 'SY-dur' is more common in speech.

Source: www.rfc-editor.org(official spec)