480 likes | 939 Views
IPv6 Introduction. What is IPv6 Purpose of IPv6 (Why we need it) IPv6 Addressing Architecture IPv6 Header ICMP v6 Neighbor Discovery (ND) Reference Site. What is IPv6. IP version 6 (Now is IP version 4) IPng (IP The Next Generation) RFC791 IPv4 header IPv6 header
E N D
IPv6 Introduction • What is IPv6 • Purpose of IPv6 (Why we need it) • IPv6 Addressing Architecture • IPv6 Header • ICMP v6 • Neighbor Discovery (ND) • Reference Site
What is IPv6 • IP version 6 (Now is IP version 4) • IPng (IP The Next Generation) • RFC791 • IPv4 header IPv6 header • IPv4 structure IPv6 structure • Plug and Play
IPv6 address allocation in Asia 資料來源:http://www.ipv6.org.tw/
IPv6 subnets in Taiwan 資料來源:http://www.ipv6.org.tw/
Purpose of IPv6 • IPv4 address bottleneck • CIDR (Classless Inter-Domain Routing) • NAT (Network Address Translation) • 3G and IA (Information Appliance) • Network Security • IPsec (IP security) • Wireless Mobile Issue • Triangle Issue
Purpose of IPv6 (cont.) • Running out of address in IPv4 • 32-bit vs. 128-bit • 75% IP addresses in America • 3G & IA production • Multicast function is not useful • Checksum in 2 Layers • CIDR is the default usage (without netmask)
Purpose of IPv6 (cont.) • Simply the complex Header • Reduce router’s loading • Extension Header • More Security with IPsec • QoS (Quality of Service) • Auto-Configuration • Statefull (DHCPv6) • Stateless (RS,RA)
IPv6 Feature (cont.) Neighbor Cache Routing Table Destination Cache Prefix List ARP Table Default Router List IPv4 IPv6
IPv6 Addressing Architecture • IPv6 Address Rule • Unicast Address (RFC2374) • Link local address • Site local address • Global address • Anycast Address (RFC2526) • Multicast Address (RFC2375) No Broadcast Here!!!!!!
IPv6 Address Rule • The preferred form is x:x:x:x:x:x:x:x • X is 16 bit value • Long strings of zero bits • 0:0:0:0:0:0:0:1 ::1 • “前導0” could be skipped • FFEE:BBBB:00A0:0:0:0:0:1 FFEE:BBBB:A0::1 • The "::" can only appear once in an address
Unicast Address-Link local • Link local address • Used on a single link • Prefix is 1111 1110 10 • FE80: • Usage Timing • Automatic Address Configuration • Neighbor Discovery
Unicast Address-Site local • Site local address • Used on a single site • Prefix is 1111 1110 11 • FEC0:
Unicast Address-Global • Global address • Unique in Internet • Prefix is 001
Anycast Address • When a unicast address is assigned to more than one interface, thus turning it into an anycast address, the nodes to which the address is assigned must be explicitly configured to know that it is an anycast address.
R1 R2 A B Lower Cost R3 Anycast Area Anycast Usage
Multicast Address • flags 000T (focus on T value) • 0 permanently-assigned (well-known address) • 1 non-permanently-assigned (transient) • scope • 1:node-local scope • 2:link-local scope • 5:site-local scope • 8:organization-local scope • Others:reserved Ex:ff02::1 (link-local) all nodes multicast address
Interface ID • Created from MAC address • EUI-64 Address • Example for link-local: • MAC addr: 00-01-23-AA-BB-CC • EUI-64: • 00-01-23 AA-BB-CC • 00-01-23 FF-FE AA-BB-CC • 00-01-23 -FF-FE-AA-BB-CC • FE80::1:23FF:FEAA:BBCC/64 <- link-local addr.
IPv6-IPv4 comparison IPv6 • Unspecified Host • 0:0:0:0:0:0:0:0 (::) • Loopback • ::1 • Multicast • FF02::1 • Netmask • Prefix Number IPv4 • Unspecified Host • 0.0.0.0 • Loopback • 127.X.X.X • Broadcast • 192.168.0.255 • Netmask • 255.255.255.0
Routing Header • Created only when use PATH MTU function • PATH MTU:Trying to find out the biggest MTU size. (RFC 1981)
Fragment Procedure All Data
ICMP v6 • Internet Control Message Protocol • RFC 2463
ICMP sample A Ping B A B
ICMP v4 vs. ICMP v6 • ICMP v6 • echo request message • Type 128 • echo reply message • Type 129 • Code 0 • ICMP v4 • echo message • Type 8 • reply message • Type 0 • code 0
Neighbor Discovery (ND) • RFC2461 • Corresponds to a combination of IPv4 • ARP • ICMP Router Discovery • ICMP Redirect
Neighbor Discovery • 5 messages • Neighbor Solicitation (NS) • Neighbor Advertisement (NA) • Router Solicitation (RS) • Router Advertisement (RA) • Redirect • All these messages should fill 255 in hop limit field • Link Layer address
Regular RA (Type 133) Use multicast to send its prefix to link-local scope all-nodes
Reference Site • www.ipv6.org.tw • www.ietf.org