IPv6 Addressing Schemes Flashcards
1
Q
IPv6
A
IP version 6
- provides long-term solution to problems of inefficient addressing schemes and demand for more addresses
- 128 bit scheme with 340 undecillion unique addresses
2
Q
IPv6 Packet
A
- Consists of 2 or 3 elements:
Main header (which is a fixed length)
One or more options extension headers
Payload
3
Q
Canonical notation
A
- Method to compress hex notation
- When a double byte contains double 0s they can be ignored
- A contiguous string of 0s can be replaced with ::
2001:0db8:0000:0000:0abc:0000:def0:1234
=
2001:db8::abc:0:def0:1234
4
Q
IPv6 Network Prefixes
A
- First 64 bits are network ID
- Second 64 bits are interface ID
- Interface ID(Host ID) is always 64 bits
- Uses classes notation and /nn is length of network prefix
- If two hosts share same prefix they are on same network
- Can use unicast, multicast and anycast addressing
- There is not broadcast address
5
Q
IPv6 Unicast Addressing
A
- Scoped, meaning it addresses region of the network
- Global addressing scopes provide equivalent of IPv4 public addressing
- Link local schemes provide private addressing
6
Q
IPv6 Global Addressing
A
- Globally scoped unicast addresses are routable over the internet and are the equivalent of IPv4 public addreses
- First 3 bits indicate addres within global scope
- In hex, will start with a 2 or 3
- Next 45 bits are allocated to regional registries, then to IPs, then end users
- Next 16 bits identify subnet addresses
- Final 64 bits are interface ID
7
Q
IPv6 Interface ID (MAC Derived)
A
- Interface ID can be determined with 2 techniques
- One is using MAC address(MAC derived address)
- Mac is 48 bits and can be converted to 64 bit (EUI-64)
- First, digits fffe are added to middle of MAC address
- Second, first 8 bits(2 hex digits) are converted to binary and the 7th bit flipped from 1 to 0 or 0 to 1.
8
Q
IPv6 Interface ID (Privacy Extension)
A
- Uses pseudorandom number for interface ID
- Known as interface ID or token
- Mitigates concern that host could be identified and monitored when connecting to internet
9
Q
Link Local addresses
A
- Span a single subnet
- Are not forwarded by routers
10
Q
IPv6 Link Local Addressing
A
- Link local range is fe80::/10
- Link local addresses start with fe80
- Next 54 bits are set to 0
- Last 64 bits are interface ID
- Equivalent is APIPA and it’s 169.254.0.0 addreses
- IPv6 host always has a link local address, even if it has globally unique address
11
Q
Zone Index
A
- Appends link local address
- Used to define source of address and make it unique to a particular link
12
Q
IPv6 Auto addressing
A
- Addreses can be assigned statically or used automatic addressing scheme
13
Q
Neighbor Discover Protocol
A
- performs some functions of ARP and ICMP do
Address autoconfiguration: Enables host to configure addreses for it’s interfaces and detect address already in use local network using neighbor solicitation and neighbor advertisement
Prefix discovery: Enbables host to discover network prefixes for local segment
Local address resolution: allows host to discover other nodes and routers on local network
Redirection: enables route to inform host of a better route to a destination
14
Q
SLAAC
A
Stateless Address Autoconfiguration
- What IPV6 uses instead of DHCP
- Host generates link local addresses and tests that it unique with neighbor discovery
- Host listens for router advertisement or transmits router solicitation
- Router can either provide network prefix or direct host to DHCPv6 server to perform stateful autoconfiguration
15
Q
ICMPv6
A
- Updates version of ICMP
- Supports error message, but added Packet too big class of error
- Supports neighbor discovery and neighbor and router advertisements
