About this interactive
From the lesson:
- **Multicast groups:** every IPv6 device joins ff02::1 (all nodes); routers also join ff02::2 (all routers). IPv6 has no broadcast.
- **Router solicitation** goes to ff02::2. **Router advertisements** go to ff02::1, periodically and in reply, carrying the prefix and the router's own address, which becomes the default gateway.
- **Host bits:** with the A flag set the host builds its own 64 host bits: EUI-64 from the MAC address (Cisco's default) or random (Windows' default).
- **Duplicate address detection:** the host sends a neighbor solicitation for its new address. No answer, it keeps it; a neighbor advertisement in reply means the address is taken.
What you'll learn
- Predict the SLAAC steps: router solicitation to ff02::2, router advertisement to ff02::1, the host building its own host bits on the advertised prefix, and duplicate address detection
- Tell EUI-64 host bits, built from the MAC address and Cisco's default, from random host bits, Windows' default
Aligned to
Cisco CCNA
1.8
Configure and verify IPv6 addressing and prefix
1.9
Describe IPv6 address types
Key terms
- Stateless Address Autoconfiguration
SLAAC
- An IPv6 mechanism that allows devices to automatically generate a globally unique IPv6 address using the network prefix from a Router Advertisement combined with a locally generated interface identifier, without requiring a DHCP server. SLAAC uses the EUI-64 process or a random interface ID to create the host portion of the address.
- Router Solicitation
RS
- An ICMPv6 message sent by an IPv6 host when it initializes to prompt routers on the link to send a Router Advertisement immediately, rather than waiting for the next periodic RA interval. Router Solicitation speeds up IPv6 address autoconfiguration on newly connected devices.
- Duplicate Address Detection
DAD
- An IPv6 mechanism that verifies a newly assigned address is unique on the link before it is used for communication. A device sends a Neighbor Solicitation for its tentative address; if no response is received, the address is confirmed unique and assigned.
- Extended Unique Identifier 64-bit
EUI-64
- A method for automatically generating the 64-bit interface identifier portion of an IPv6 address by inserting 0xFFFE into the middle of a device's 48-bit MAC address and flipping the Universal/Local bit. EUI-64 is used by SLAAC and stateless DHCPv6 to create host-specific IPv6 addresses.
- Neighbor Solicitation
NS
- An ICMPv6 message used in IPv6 Neighbor Discovery to request the MAC address corresponding to a specific IPv6 address or to verify that a neighbor is still reachable. Neighbor Solicitation is also used during Duplicate Address Detection to check that a new IPv6 address is unique.
- Neighbor Advertisement
NA
- An ICMPv6 message sent in response to a Neighbor Solicitation, providing the MAC address corresponding to a requested IPv6 address as part of the Neighbor Discovery Protocol. NA messages are also sent unsolicited to announce link-layer address changes.
- Multicast Group
- A set of devices that have subscribed to receive traffic sent to a specific multicast address.
Topics
Ipv6
Slaac
Ndp
Eui 64
Duplicate Address Detection
Interactive
Predict
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