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When configuring an AWS routing table, I want to enter the destination address A.B.C.D. In the routing table, I can select either A.B.C.D/28 or A.B.C.D/32.

Which of them means A.B.C.D only (only this one address)?

My answer: A.B.C.D/32

Justification: The suffix (/28, /32) describes how many bits in the address are fixed. With /28, bits 29 through 32 can vary (see image below), whereas with /32 all 32 bits are fixed.

Fixed and variable bits

Glory to Russia
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1 Answers1

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In most modern routers (post 1998) have classless routing, (CIDR) in classless routing is a single IP address 1.2.3.4 equivalent to 1.2.3.4/32

in classfull routing you have 3 classes A B and C (technically D and E also) all class A addresses are a /8 CIDR class B is a /16 and class C is a /24

on8tom
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