IPv6: The Signs Get Longer
7:40Coming soon
The city ran out of 32-lamp signs, so it made them 128 lamps long. This lesson teaches you to read an IPv6 address without fear: hex four lamps at a time, eight groups, and the two shortening rules the exam tests. Then the split that never moves (the street is /64, and there is no mask), the four kinds of address you'll meet, and two things that are simply gone: the broadcast address, and the trip to the DHCP server.
You'll learn
- Why IPv6 exists: 2^32 signs ran out, 2^128 won't
- Reading the long sign: 128 bits in eight hex groups, with the 8-4-2-1 lamp card for each hex digit
- The two shortcuts: leading zeros vanish in each group, and one :: for the longest run of zero groups
- Street and house: the first 64 bits name the subnet, the last 64 the host; /64 everywhere, no subnet mask
- The /48 for a site and the fourth group as the subnet number: 65,536 subnets per building
- Four kinds of address: global unicast (2…/3…), link-local (fe80::), unique local (fd…), loopback ::1
- No broadcast in IPv6: multicast ff02::1 (all nodes) does the job
- SLAAC: the router advertises the prefix and the host builds its own interface ID; DHCPv6 is optional
- Neighbour discovery replaces ARP; dual stack keeps both addresses on one interface
- The real thing: ipconfig with a global, a temporary and a link-local address, and two default gateways
- Exam corner: the correct shortened form of 2001:0db8:0000:0000:0000:ff00:0042:8329
Chapters
- 0:00The city ran out of signs
- 0:36Reading the long sign: hex and eight groups
- 1:21The two shortcuts
- 1:51Street and house: the split at 64, no mask
- 2:56Four kinds of sign
- 3:39No bell tower: no broadcast
- 4:02How a house gets its sign: SLAAC
- 4:36Neighbour discovery and dual stack
- 5:06The real names
- 5:56The real thing: ipconfig with both signs
- 6:31Exam corner
- 6:59Recap and next time
Exam objectives: CompTIA Network+ N10-009: 1.7 (IPv6 addressing: global unicast, link-local, unique local, multicast, loopback; SLAAC; address compression; dual stack), 5.5 (ipconfig).
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