IP6 Flashcards
Why IPv6 exist?
IPv4 was ranning out of available IP addresses. =4.2 billion addresses so IPv6 was created =340 undecilion addresses
IPv6 IP address size?
128 Bit address (32 hexadecimal digits) x 4bits = 128bits
IPv4 addres size?
32 Bit address 4 octed by
What does not have in IPv6?
No broadcsts No Fragmentation - (no maximum MTU size)
Dual stack
Network running IPv4 and IPv6 together. Routers do have the capability to do both.
Tunneling
Take IPv6 and tunneled over IPv4 (if the router doesn’t support IPv6 by default)
How to simplify IPv6 address?
Consecutive groups of 0`s can be summarized as :: (double collin) 2018:0:0:0000:0:000:4815:54:ae 2018::4815:54ae
Globally routable unicast addresses
Beggins with 2000 to 3999
Link-Local address
Multicast address
Begins with FF
Do you need DHCP in IPv6?
NO
IPv6 uses auto configuration to discover the current network and selects its own host ID based on its MAC
Using the EUI64 process
If you want to still use DHCP,
there is a DHCPv6 protocol
IPv6 uses Neighbour Discoveri Protocol (NDP)
to learn the Layer 2 addresses on the network
(NDP)
Neighbour Discovery Protocol
Used to learn Layer 2 addresses on network
Performs:
No broadcasts! • Operates using multicast over ICMPv6
- Router Solicitation
- Router Advertisement
- Neighbour Solicitation
- Neighbour Advertisement
- Redirection
Router Solicication
Hosts send message to locate routers on the link
(Hey, any routers out there?)
Router Advertisement
Routers advertise their presence periodically, or in response to an RS message.
(Hey, I am still here)
( RA includes: various link and Internet parameters, hop limit value, etc)
Neighbour Solicitation
Neighbor Solicitation (NS) is sent by a node to determine the link-layer address of a neighbor,
or to verify the neighbor is still reachable via a cached link-layer address.
also used for Duplicate Address Detection (DAD).
(There’s no ARP in IPv6)
Redirect
Routers informing host of better first-hop routers for a destination
Neighbour Advertisement
Neighbour Advertisement (**NA**) is sent in response to an NS message. A node may also announce a link-layer address change.
Unicast
Unicast is 1 to 1 communication
Multicast
Multicast is 1 to many communication
(IPv6 dont have broadcast)
IPv6 has many different type of multicast addresses for different purposes.
Well-known
Solicitated-Nodes
Anycast
Anycast is 1 to anyone of a group.
When we send anycast packet,
We mean - send the packet to the closest member (router) of this group
Anycast is typically used by routers
An IPv6 anycast address is an address that can be assigned to a group of routers.
Multiple routers can have the same anycast address.
Multicast type addreses
- *Well-know** - Reserved for predifined group of devices - all nodes and all routers multicast groups.
- *FF02::1** is all nodes adrs
- *FF02::2** is all routers adrs
Solicitated-Node - automatically created by prepending the solicited-node multicast prefix FF02::1:FF00:0000/104 to the last 24 bits of the unicast or anycast address.
