CIDR Query
control
Member Posts: 309
in CCNA & CCENT
Question from Odoms icnd2 book.
Which of the following summarised subnets represent routes that could have been created for CIDRS goal to reduce the size of Internet routing tables.
A. 10.0.0.0. 255.255.255.0
B. 10.1.0.0 255.255.0.0
C. 200.1.1.0 255.255.255.0
D. 200.1.0.0. 255.255.0.0
The answer is D, but how is this worked out?
Thanks
Which of the following summarised subnets represent routes that could have been created for CIDRS goal to reduce the size of Internet routing tables.
A. 10.0.0.0. 255.255.255.0
B. 10.1.0.0 255.255.0.0
C. 200.1.1.0 255.255.255.0
D. 200.1.0.0. 255.255.0.0
The answer is D, but how is this worked out?
Thanks
Comments
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astorrs
Member Posts: 3,139 ■■■■■■□□□□
"Internet routing tables" rules out A and B as 10.0.0.0/8 is defined private as part of RFC 1918 and is never routed by Internet routers; 200.x.x.x is a class C address space which has a mask of 255.255.255.0 by default, so C isn't a summarization; D is the answer and summarizes 256 class C's or ~65k hosts.