IPv6的簡介

1. IPv6 Introduction

2. Agenda
• IPv6 Addressing
– What is IPv6
– ICMPv6 (Stateless)
– DHCPv6 (Stateful)
• IPv6 Routing
– Static Routing
– Adaptive Routing
• IPv6 Service
– DNSv6
– IPv6 to IPv4 Transition
• Linux IPv6 Implementation

3. IPv4/IPv6 Protocol Stack

4. What is IPv6
• IPv4 (32bits) → IPv6 (128 bits)
– 2001:0db8:1a2b:0015:0000:0000:1a2f:0000
• 2001:db8:1a2b:15:0:0:1a2f:0
– (0 can ignore)
• 2001:db8:1a2b:15::1a2f:0
– multiple “0” block can combine to :: (only once)
• Prefix is network address
– 2001:0:0:b3::1234/64
• Address type
– Unicast
– Multicast [Multicast Listener Disscovery]
– Anycast (router only)

5. IPv6 Unicast Address
• Unicast address type
– Global
• Unique
• Start 001x+ network addr + 64 bits interface addr
– Local Link
• Cannot pass through Router
• fe80:: + 64 bits interface addr / 10
• EUI-64 (transfer MAC to IPv6 interface address)
– 7th
bit change to complementation
– Add FFFE in the 3th and 4th
• 00:ab:cd:12:34:56 → 02ab:cdff:fe12:3456
• IPv6 address method
– manual, auto-configuration (stateless, stateful)

6. IPv6 Auto Configuration

7. Stateless Auto Configuration
• ICMPv6 ()
– Fault management
• Ping6
• traceroute6
– Multicast Listener Discovery (MLDv2)
• Replace IGMPv3
– Neighbor Discovery
• Router Solicitation (RS)
• Router Advertisement (RA)
• Neighbor Solicitation (NS)
• Neighbor Advertisement (NA)
• Redirect

8. Router Advertisement Header
• M
– 1 : get Prefix from DHCP server
– 0 : get Prefix from Router
• O
– 1 : get DNS from DHCP server
– 0 : get DNS from Router

9. ICMPv6 Router Discovery

10. ICMPv6 Router Discovery

11. ICMPv6 Address Resolution

12. ICMPv6 Address Resolution

13. Stateful Auto Configuration
• DHCPv6 (RFC 3315)
– DHCPv6 client can request multiple IPv6 address
– 4-way messages exchange (Stateful)
• M=1, O=0
• Solicit(C) / Advertise(S) / Request(C) / Reply(S)
– 2-way messages exchange (Stateless)
• Information-request(C) / Reply (S)
• DHCP Roles
• M=0, O=1
– Client
– Server
– Relay Agent

14. DHCPv6 working

15. Auto Configuration Process
• Allows a host to create a unicast address from:
– Its MAC address
– Prefixes sent by neighbor routers
• Several steps:
– Link-local addresses creation
– Duplicate addresses detection (DAD)
– Discover the routers on-link (RS/RA)
– " Configure hosts global addresses
– Configure other parameters: default router, link MTU, …
• Addresses are not automatically registered in the DNS
– Need for DNS Dynamic Update (RFC 2136 and RFC 3007)

16. Auto Configuration Flowchart

17. IPv6 Routing
• Routing Algorithm
– Increase throughput
– Decrease average delay

18. Routing Type
• Static routing (Peer to Peer, Host)
– The same as IPv4
• Specify source, destination, distance
• Adaptive routing (Router to Router)
– Distance Vector Concept
• RIPng (RFC2080)
– Link-State Concept
• OSPFv3 (RFC 5340)

19. Distance Vector Concept

20. Link-State Concept

21. Distance Vector Routing v.s.
Link-State
Routing

22. IPv6 Routing Protocols

23. RIPng
• Same as IPv4
– Distance vector, radius of 15 hops, split horizon, and
– poison reverse
– Based on RIPv2
• Updated features for IPv6
– IPv6 prefix, next-hop IPv6 address
– Uses the multicast group FF02::9 for RIP updates
– Uses IPv6 for transport
– Updates are sent on UDP port 521
• Named RIPng

24. OSPFv3
• Based on OSPFv2, with enhancements
• Distributes IPv6 prefixes
• Runs directly over IPv6
• Ships in the night with OSPFv2
• Adds IPv6-specifific attributes:
– 128-bit addresses
– Link-local address
– Multiple addresses and instances per interface
– Authentication (now uses IPsec)
– OSPFv3 runs over a link, rather than a subnet

25. DNSv6
• Domain Name System version 6
– Mapping Domain name and IP
• Client / Server Architecture
• Application
– ISC BIND-9.2.2 (Linux)
• Support IPv4 & IPv6 DNS query
• AAAA records
• renumbering
– Windows Server 2008

26. IPv6 to IPv4 Transition
• Dual Stack
– Support IPv4 & IPv6 on the same time
– IPv4 only, IPv6 only, Dual Stack
– Need one IPv4 and one IPv6 address

27. IPv6 to IPv4 Transition
• Tunneling
– Add IPv4 header

28. IPv6 to IPv4 Transition
• Translator
– Network Address Translation – Protocol
Translation
– Like IPv4 NAT
– IPv4 Address pool + sock port number
– It is deprecated on 2007/7

29. Linux IPv6 implementation
• IPv6 Addressing
– Linux 2.6.x ~
• ipv6 protocol stack, ip6tables, …
– DHCPv6 (ISC DHCP-4.1.2)
• IPv6 Routing
– IPv6 router (radvd-1.1.5)
• ICMPv6 RA, ipv6 routing
– IPv6 routing protocol (quaga-0.98)
• BGP4, BGP4+, OSPFv2, OSPFv3, RIPv1, RIPv2, RIPng
• IPv6 Service
– DNSv6 (bind-9.2.2), Tunnel Broker (gogoc), NTP (ntp-
4.2.4), SMTP (mailx-12.4), SNMP (netsnmp-5.2.1),
PPP(ppp-2.4.4), WWW(boa-0.94.13), …

30. How to enable IPv6 Router
(radvd)
# yum search radvd // search radvd
# yum install radvd // install radvd
# vi /etc/radvd.conf // edit configuation
interface eth0
{
AdvSendAdvert on;
MinRtrAdvInterval 3;
MaxRtrAdvInterval 10;
prefix 2001:db8:0:f101::1/64
{
AdvOnLink on;
AdvAutonomous on;
AdvRouterAddr on;
};
};
# echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
# echo 1 > /proc/sys/net/ipv6/conf/default/forwarding
#service radvd start

31. Reference
• http://www.ngnet.it/e/ipv6proto/ipv6-proto-
6.php
• http://www.ipv6.hinet.net/index.html
• http://www.rd.ipv6.org.tw/
• IPv6 應用及路由實務 - 訓練教材
• http://www.ithome.com.tw/itadm/article.ph
p?c=66363&s=6
• http://interop.ipv6.org.tw/index.php