ipv6 introduction what is ipv6 purpose of ipv6 (why we need it)purpose of ipv6 ipv6 addressing...
TRANSCRIPT
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
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.)
Routing Table
ARP Table
IPv4
Neighbor Cache
Destination Cache
IPv6
Prefix List
Default Router List
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:
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.
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
IPv4• Unspecified Host
– 0.0.0.0
• Loopback– 127.X.X.X
• Broadcast– 192.168.0.255
• Netmask– 255.255.255.0
IPv6• Unspecified Host
– 0:0:0:0:0:0:0:0 (::)
• Loopback– ::1
• Multicast– FF02::1
• Netmask– Prefix Number
Routing Header
• Created only when use PATH MTU function
• PATH MTU : Trying to find out the biggest MTU size. (RFC 1981)
ICMP v4 vs. ICMP v6
• ICMP v4– echo message
• Type 8
– reply message• Type 0
– code 0
• ICMP v6– echo request
message• Type 128
– echo reply message
• Type 129
– 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