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Cisco CCNA 1.9 Cisco CCNA 1.8 CompTIA Network+ 3.4
TechKnowSurge Catalog Interactives Router Discovery Address Calculator
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Router Discovery Address Calculator

Fill in the addresses of a router solicitation and advertisement, the default gateway a host learns, and the address SLAAC builds.

⚑ Complete this interactive to capture a CTF flag worth 5 points.

About this interactive

A host that has just confirmed its link-local address asks the routers on its link for the network it is on. Its router solicitation goes from its link-local address to the all-routers group, in a frame to that group's 33:33 MAC address. A router answers with a router advertisement sent from its own link-local address, never its global one, usually to the all-nodes group, so every host on the link hears it. The advertisement carries the prefix and prefix length, usually a /64, and can carry options such as the MTU and DNS servers. The host joins the 64-bit prefix to its own 64-bit interface ID to make its global address with SLAAC, and it takes its default gateway from the advertisement's source address: the router's link-local address, which is why ipconfig shows an fe80 gateway. For example, a prefix of 2001:db8:9::/64 and an interface ID of 0:0:0:2a give 2001:db8:9::2a. Seven of the fourteen questions are drawn each run. Any you miss shows the answer and how to work it out.

What you'll learn

Aligned to

Cisco CCNA
1.9 Describe IPv6 address types
1.8 Configure and verify IPv6 addressing and prefix
CompTIA Network+
3.4 Given a scenario, implement IPv4 and IPv6 network services

Key terms

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.
Default Gateway
The router that a device uses to send traffic to destinations outside its local network.
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.
Link-Local Address
An IPv6 address in the FE80::/10 range that is automatically assigned to every IPv6-enabled interface and used only for communication within a single network link. It cannot be routed beyond the local Layer 2 segment and is required for Neighbor Discovery and router communication.
IPv6 Prefix Length
A value expressed in slash notation that identifies how many leading bits of an IPv6 address represent the network portion, functioning similarly to CIDR notation in IPv4.

Topics

Ipv6 Ndp Router Solicitation Slaac Default Gateway Interactive Calculation

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