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5 votes
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Simple IPv6 Global Unicast question

Left most 001 are fixed, this means the left most nibble can be: 0010 = 0x2 0011 = 0x3 The 4th left most bit is not fixed.
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5 votes
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Why shortened version of IP4 exists and it is undocumented but supported everywhere?

Take a look at Textual Representation of IPv4 and IPv6 Addresses In particular: Meanwhile, a very popular implementation of IP networking went off in its own direction. 4.2BSD introduced a ...
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4 votes

Why shortened version of IP4 exists and it is undocumented but supported everywhere?

Those variants are remnants from the classful networking era that ended in 1993. They allowed you to use the class prefix in combination with a single, host-specific number, but not limited to that. ...
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3 votes
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Why the host part of a Mask is 254 (256-2) instead of 253?

Your question is unclear, but if you ask "why can we have 254 hosts in a /24 network" then: the all zero is also an address, so while it add ups to 255 as you said, it doesn't start from 1 ...
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2 votes

Why is this 254.63.0.1, not a valid host address?

240.0.0.0/4 is reserved by ARIN (SPECIAL-IPV4-FUTURE-USE-IANA-RESERVED). Likely, the switch is rejecting that address because it's part of the pre-1993 class E address range. Many hosts and devices ...
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2 votes

Why the host part of a Mask is 254 (256-2) instead of 253?

Because you have 256 different values: 0 to 255. The same thing for the number of decimal digits. There are 10 digits (base 10) but they are 0 to 9. Since you have 256 different values in an octet (0 ...
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2 votes

How is 65535 bytes is total length of IP datagram?

It is because the number in that field is the number of octets (bytes) for the entire packet. You could never have a number less than 20 because that is the minimum IPv4 header size. If he field has ...
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1 vote

What should we do if the number of bytes to be transferred are not in multiples of eight in ipv4?

The number of octets in an IPv4 packet need not be a multiple of eight. You are confusing a couple of things. The data size can be anywhere from 0 to 65,535 - <packet header size>. IPv4 has the ...
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1 vote

Simple IPv6 Global Unicast question

Remember that four bits are used for each hexadecimal digit. 0010 and 0011 are the bits for the first hexadecimal digit in /3, and the correspond to 2 and 3 in hexadecimal. The first three bits are ...
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1 vote

DHCP Discover Broadcast and its IP (255.255.255)

255.255.255.255 is the broadcast address for all subnets.
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1 vote

Why in the TCP/IP model the link & physical are one?

The internet was a project to connect disparate networks into a coherent whole. It was neither necessary nor desirable for the architects of the internet to worry about how exactly those underlying ...
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