السلا م عليكم.................

أرجو من اخوانى المساعده فى فهم هذه الجزئية البسيطة فى هذا المثال ............


You want to create a standard access list that denies the

subnet of the following host
172.16.50.172/20
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فى اجابة هذا السؤال
First, you must know that a /20 is 255.255.240.0, which is a block size of 16 in the third octet. Counting by 16s,this makes our subnet 48 in the third octet,
وهتكون الاجابة هى
access-list 10 deny 172.16.48.0 0.0.15.255
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أنا عايز أفهم ال 48 دى جات ازاى بالظبط؟؟؟؟