HEXIDECIMAL (Review)
What about the reverse (Hex to Binary) ???
WHY IPv6?
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The MAIN REASON is that there are simply not enough IPv4 addresses available
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There are 2^32 IPv4 Addresses available (4,294,967,296)
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When IPv4 was being designed 30 years ago, the creators had NO idea the Internet would be as large as today
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VLSM, Private IPv4 ADDRESSES, and NAT have been used to conserve the use of IPv4 ADDRESS SPACE.
- These are short-term solutions, however.
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The LONG -TERM solution is IPv6
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IPv4 ADDRESS assignments are controlled by IANA (Internet Assigned Number Authority)
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IANA distributes IPv4 ADDRESS space to various RIRs (Regional Internet Registries), which then assign them to companies that need them.
- On September 24th, 2015, ARIN declared exhaustion of the ARIN IPv4 address pool
- On August 21st, 2020, LACNIC announced that it had made its final IPv4 allocation
BASICS OF IPv6
- An IPv6 ADDRESS is 128 bits (8 bytes)
- An IPv6 ADDRESS uses the / prefix number
SHORTENING (Abbreviating) IPv6 ADDRESSES
EXPANDING (Abbreviating) IPv6 ADDRESSES
FINDING the IPv6 PREFIX (GLOBAL UNICAST ADDRESSES)
- Typically, an Enterprise requesting IPv6 ADDRESSES from their ISP will receive a /48 BLOCK
- Typically, IPv6 SUBNETS use a /64 PREFIX LENGTH
- That means an Enterprise has 16 bits to use to make SUBNETS
- The remaining 64 bits can be used for HOSTS
(Each digit is 4 bits / each 4 digit block is 16 bits)
REMEMBER : You can only remove the LEADING ZEROS !!!
2001 : 0DB8 : 8B00 : 0001 : FB89 : 017B : 0020 : 0011 /93
Because 93 lands in the middle of a 4 bit number, we need to convert the last digit to binary and borrow a “bit” from the first binary digit.
:: 017 [B] :: B = 0d11 = 0b1011 = 0b1000 (the first digit is borrowed, the remainder become 0)
CONFIGURING IPv6 ADDRESSES
This allows the ROUTER to perform IPv6 ROUTING
💡 R1(config) #ipv6 unicast-routingConfiguring an INTERFACE with an IPv6 Address
💡 R1(config) #int g0/0 R1(config-if) #ipv6 address 2001:db8:0:0::1/64 R1(config) #no shutdownYou can also type out the full address (if necessary)
NOTE ABBREVIATED IPv6 ADDRESSES SHOWN
LINK-LOCAL ADDRESSES are automatically added when creating an IPv6 INTERFACE (Covered in IPv6 - PART 2 Lecture)