1.8 IPv6 Addressing Flashcards
N10-009 Obj. 1.8 Summarize evolving use cases for modern network environments. (12 cards)
Why is IPv4 no longer sufficient for modern Internet needs?
IPv4 supports only 4.29 billion addresses, which is far fewer than the 20+ billion devices currently connected to the Internet.
Transcript: “IP version 4 can only support 4.29 billion… we’ve hit the limit…” (0:16–0:42)
What is IPv6 and how does it solve IPv4 limitations?
IPv6 is a 128-bit addressing scheme providing a vastly larger address space, solving the limitations of IPv4.
Transcript: “IP version 6… 128-bit address… every grain of sand… 45 quintillion unique addresses…” (1:28–2:02)
How is an IPv6 address structured?
It’s made up of eight 16-bit hexadecimal groups separated by colons, totaling 128 bits or 16 bytes.
fe80::5d18:652:cffd:8f52
Transcript: “Each section… 16 bits in length… total of 128 bits or 16 bytes…” (3:01–3:25)
What are two rules for compressing IPv6 addresses?
- Leading zeros in each group can be removed.
- A contiguous group of all-zero sections can be replaced with a double colon (::), but only once per address.
fe80::5d18:652:cffd:8f52
fe80:0000:0000:0000:5d18:0652:cffd:8f52
Transcript: “Remove leading zeros… replace groups of zeros with double colons…” (4:05–5:14)
Why can’t IPv4 and IPv6 communication directly?
Because their addressing formats and protocols are fundamentally different, requiring transition mechanisms like tunneling, dual stack, or translation.
Requires an alternate form of communication
* Tunnel - Encapsulate one protocol within another
* Dual-stack - Have the option to use both IPv4 and IPv6
* Translate - Convert between IPv4 and IPv6
Transcript: “IP version 6 and IP version 4 cannot directly communicate…” (6:31–6:49)
What is dual-stack routing?
It allows a device to use both IPv4 and IPv6 simultaneously, enabling compatibility with both types of networks.
Transcript: “Dual-stack routing… use both IP version 4 and 6 at the same time…” (9:30–10:01)
What is NAT64 and how does it help with IPv6 to IPv4 communication?
NAT64 translates IPv6 addresses into IPv4 addresses using a special router and DNS64 server, enabling communication between incompatible protocols.
Transcript: “NAT64… translates IPv6 to IPv4… uses specialized router and DNS64 server…” (11:08–11:56)
What is DNS64 and what role does it play in IPv6 to IPv4 communication?
DNS64 is a DNS server that translates DNS queries from IPv6 clients to retrieve IPv4 addresses, enabling NAT64 to function.
Transcript: “DNS64… translates the DNS requests from IP version 4 to IP version 6…” (11:47–12:00)
How does the NAT64 process work when an IPv6 client accesses an IPv4-only server?
DNS64 resolves the IPv4 address and redirects to a NAT64 router, which translates and forwards traffic between IPv6 and IPv4 networks.
Transcript: “NAT64… client thinks it has IPv6 address… router handles translation…” (12:13–13:35)
What is 6to4 addressing and why is it no longer used?
A tunneling method for sending IPv6 over IPv4 that required relay routers and didn’t support NAT. It’s now obsolete and removed from Windows.
Transcript: “6 to 4 addressing… obsolete… removed from all Windows versions…” (8:18–9:01)
What are some ways IPv4 mitigates address exhaustion?
By using Network Address Translation (NAT) to allow multiple devices to share a single public IPv4 address, extending usability despite address scarcity.
Transcript: “Network address translation… connect hundreds or even thousands of devices to the internet using a minimal number of IP version 4 addresses…” (0:23–1:05)
What is 4in6 tunneling?
A method where IPv4 traffic is encapsulated within an IPv6 network to allow communication betwen IPv4 devices across an IPv6 infrastructure. (Also rather unusual to see this today)
Transcript: “4 in 6 tunneling… tunnel IP version 4 traffic across an existing IP version 6 network…” (9:02–9:16)
