CN_IT2050_L3_IPv6.pdf

Computer Networks Lecture 3 IPv6 Addressing Why IPv6  IPv4 has a theoretical maximum of 4.3 billion addresses  plus private addresses in combination with NAT  NAT having limitations in peer-to-peer communications  With an Internet of things, devices other than computers, tablets...

Computer Networks Lecture 3 IPv6 Addressing Why IPv6  IPv4 has a theoretical maximum of 4.3 billion addresses  plus private addresses in combination with NAT  NAT having limitations in peer-to-peer communications  With an Internet of things, devices other than computers, tablets, and smartphones, sensors, Internet-ready devices, automobiles, biomedical devices, household appliances, natural ecosystems etc… need to connect to the internet. Why IPv6 How it looks like  IPv6 has a larger 128-bit address space  340 undecillion addresses. (That is the number 340, followed by 36 zeroes.)  When the IETF began its development of a successor to IPv4, so it fix the limitations of IPv4 and include additional enhancements  Ex- 2001:0DB8:0000:1111:0000:0000:0000:0200 Hextet used to refer to a segment of 16 bits or four hexadecimals  IPv4 and IPv6 Coexistence  Dual Stack –dual stack allows IPv4 and IPv6 to coexist on the same network segment. Dual stack devices run both IPv4 and IPv6 protocol stacks simultaneously.  Tunneling –tunneling is a method of transporting an IPv6 packet over an IPv4 network. The IPv6 packet is encapsulated inside an IPv4 packet, similar to other types of data.  Translation – Network Address Translation 64 (NAT64) allows IPv6-enabled devices to communicate with IPv4-enabled devices using a translation technique similar to NAT for IPv4. An IPv6 packet is translated to an IPv4 packet and vice versa. Address formats IPv6 Address - Rule 1 (Omitting Leading 0s)  The first rule to help reduce the notation of IPv6 addresses is any leading 0s (zeros) in any 16-bit section or hextet can be omitted  01AB can be represented as 1AB  09F0 can be represented as 9F0  0A00 can be represented as A00  00AB can be represented as AB IPv6 Address -Rule 2 (Omitting All 0 Segments)  A double colon (::) can replace any single, contiguous string of one or more 16-bit segments (hextets) consisting of all 0’s  Double colon (::) can only be used once within an address otherwise the address will be ambiguous  Known as the compressed format  2001:0DB8::ABCD:0000:0000:1234  2001:0DB8::ABCD:0000:0000:0000:1234  2001:0DB8:0000:ABCD::1234  2001:0DB8:0000:0000:ABCD::1234 IPv6 Address Types  There are three types of IPv6 addresses:  Unicast  Multicast  Anycast *** IPv6 does not have broadcast addresses.  IPv6 Unicast Addresses  Global unicast  Similar to a public IPv4 address.  Globally unique, Internet routable addresses.  Global unicast addresses can be configured statically or assigned dynamically.  Currently, only global unicast addresses with the first three bits of 001 or 2000::/3 are being assigned. (The first hextet has a range of (2000) to (3FFF).  Link-local  Link-local addresses are used to communicate with other devices on the same local link. (The first hextet has a range of (FE80) to (FEBF).)  Unique local  Similar to the private addresses for IPv4, but there are significant differences.  (FC00::/7 to FDFF::/7) *** 2001:0DB8::/32 address has been reserved for documentation purposes  Host Configuration  Manually configuring the IPv6 address on a host is similar to configuring an IPv4 address.  the default gateway address configured for PC1 is 2001:DB8:ACAD:1::1. This is the global unicast address of the Router GigabitEthernet interface on the same network.  the default gateway address can be configured to match the link-local address of the GigabitEthernet interface of the router. Dynamic Configuration - SLAAC  Stateless Address Autoconfiguration (SLAAC) is a method that allows a device to obtain its prefix, prefix length, default gateway address, and other information from an IPv6 router without the use of a DHCPv6 server. EUI-64 Process  IEEE defined the Extended Unique Identifier (EUI) or modified EUI-64 process. This process uses a client’s 48-bit Ethernet MAC address, and inserts another 16 bits in the middle of the 48-bit MAC address to create a 64-bit Interface ID.  Step 1: Divide the MAC address between the OUI and device identifier.  Step 2: Insert the hexadecimal value FFFE, which in binary is: 1111 1111 1111 1110  Step 3: Convert the first 2 hexadecimal values of the OUI to binary and flip the U/L bit (bit 7). In this example, the 0 in bit 7 is changed to a 1 Questions ?