Presentation on theme: "Regional Cisco Networking Academy Conference 2014"— Presentation transcript:
1Regional Cisco Networking Academy Conference 2014 Introduction to IPv6:Exactly the same as IPv4… only completely differentRick GrazianiCS/CIS InstructorCabrillo CollegeGiving you the knowledge and confidence to teach IPv6
2Topics A lot of stuff, but don’t be intimidated! Why IPv6? IPv6 and ICMPv6 at a glanceFormat of an IPv6 AddressIPv6 AddressGlobal Unicast IPv6 AddressSubnettingLink-Local Unicast IPv6 AddressStatic Configuration of a Global Unicast AddressDynamic Configuration of a Global Unicast AddressThree optionsLink-local addressMulticast addressAddress ResolutionA lot of stuff, but don’t be intimidated!
4We’re running out of IPv4 Monday, January 31, IANA allocated the last /8 IPv4 address blocks to the RIRs.RIR’s have very few IPv4 address left, if any.Many ISPs are severely limited and some have already run out.
5Internet Penetration Rate by Population About 80% of North Americahas Internet accessSome ISPs are only giving out IPv6Only 28% of Asia and 16%of Africa has Internet access
6Internet of Everything Cisco defines the Internet of Everything (IoE) as bringing together people, process, data, and things to make networked connections more relevant and valuable than ever before.Cisco estimates that there will be 50 billion “connected” devices by 2020.That’s a lot of addresses!
7No more NAT as we know it 192.168.1.0/24 RFC 1918 Private Address Public IPv4 AddressUsing NAT to “hide” IPv6 networks has been the source of some debate.IETF continues to state that NAT is not a security feature.NAT for IPv4 breaks many things.IETF does not support the concept of translating a “private IPv6” address to a “public” IPv6 address... but there are exceptions.
8Benefits of IPv6 Larger address space Stateless autoconfiguration End-to-end reachability without private addresses and NATBetter mobility supportPeer-to-peer networking easier to create and maintain, and services such as VoIP and Quality of Service (QoS) become more robust.The “killer application” for the Internet is the Internet itself.https://www.ipv6ready.org/
9You are probably already running IPv6 RSRAIPv4IPv6IPv4IPv6R1RougeRAHere is an IPv6 prefix and gatewayHere is an IPv6 prefix and gatewayI need an IPv6 prefixIPv4IPv6Windows Vista or later, Mac OSX, Linux already running IPv6Packet analyzer (Wireshark)Potential man-in-the-middle attackRS (Router Solicitations) and RA (Router Advertisements) described in other lessons.Get familiar with IPv6!
10I bought a /24 on eBay and I’m doing NAT444444, so I’m good! Now’s the time“Finding “creative” ways to keep IPv4 alive without transitioning to IPv6 is like rearranging deck chairs on the titanic.” IETFIPv4 is not going away any time soon, but it will be replaced by IPv6Now is the time to learn, test and become familiar with IPv6
11IPv6 at home Learn IPv6 in the Lab Implement IPv6 in a part of your networkSee if you get IPv6 at homeContact ISPIPv6 enabled modemIPv6 enabled routerLinksys ea6500 Router
12When do I have to go to IPv6? IPv4 and IPv6 will coexist for the foreseeable future.Dual-stack – Device running both IPv4 and IPv6.Enterprises and ISPs have to support both protocols, which is a reason to eventually go to only IPv6.
13Various Transition Strategies – Mostly for ISPs Tunneling – IPv6 packets encapsulated inside IPv4 packets.NAT64 – Translating between IPv4 and IPv6.Native IPv6 – All IPv6 (our focus and the goal of every organization).
14IPv4 and IPv6 IPv6 is more than just larger address space. It was a chance to make some improvements on the IP protocol.
15IPv6 at a Glance Next Header = Protocol field in IPv4. Indicates the data payload type (TCP, UDP, ICMPv6)Hop Limit = TTL (Time to Live) in IPv4.Number of router hops before packet is discarded.Routers do not fragment IPv6 packets unless it is the source of the packet.Use of a Link-Local Address.ICMPv6 is more robust than ICMPv4.SLAAC (Stateless Address Autoconfiguration) for dynamic addressing.
16Internet Control Message Protocol (ICMPv6) IPv6 Next Header Value: 58 decimal or 3A hexadecimalICMPv6 HeaderICMPv6 Message BodyNext Header58IPv6 HeaderIPv6 DataDescribed in RFC 4443Much more robust than ICMP for IPv4Contains new functionality and improvements.More than just “messaging” but “how IPv6 conducts business”.General message similar to ICMP for IPv4 (Type and Code fields)
17Neighbor Discovery Protocol Uses ICMPv6 ICMPv6 informational messages used by Neighbor Discovery (RFC 4861):Router Solicitation MessageRouter Advertisement MessageDiscussed with dynamic configuration of IPv6 addressesWe will also introduce assigned multicast addressesNeighbor Solicitation MessageNeighbor Advertisement MessageDiscussed with address resolution (IPv4 ARP)We will also introduce solicited node multicast addressRedirect Message (Similar to ICMPv4)Router-Device MessagingDevice-Device Messaging
19IPv6 Address Notation One Hex digit = 4 bits 2001:0DB8:AAAA:1111:0000:0000:0000:0100/642001 : 0DB8 : AAAA : 1111 : 0000 : 0000 : 0000 : 010016 bits116 bits216 bits316 bits416 bits516 bits616 bits716 bits8IPv6 addresses are 128-bit addresses represented in:Eight 16-bit segments or “hextets” (not a formal term)Hexadecimal (non-case sensitive) between 0000 and FFFFSeparated by colonsReading and subnetting IPv6 is easier than IPv4!
20How many addresses does 128 bits give us? 2001:0DB8:AAAA:1111:0000:0000:0000:0100/642001 : 0DB8 : AAAA : 1111 : 0000 : 0000 : 0000 : 010016 bits16 bits16 bits16 bits16 bits16 bits16 bits16 bitsHow many addresses does 128 bits give us?340 undecillion addesses or …340 trillion trillion trillion addresses or …“50 billion billion billion addresses for every person on earth” or….“A string of soccer balls would wrap around our universe 200 billion times!” … in other words …You won’t need to learn IPv7 for the next version of CCNA!
21This isn’t the first time Early versions of CCNA included:IPv4AppletalkIPX
22Rule 1: Leading 0’sTwo rules for reducing the size of written IPv6 addresses.The first rule is: Leading zeroes in any 16-bit segment do not have to be written.2001 : 0DB8 : 0001 : 1000 : 0000 : 0000 : 0ef0 : bc002001 : DB8 : 1 : 1000 : 0 : 0 : ef0 : bc002001 : 0DB8 : 010d : 000a : 00dd : c000 : e000 : 00012001 : DB8 : 10d : a : dd : c000 : e000 : 12001 : 0DB8 : 0000 : 0000 : 0000 : 0000 : 0000 : 05002001 : DB8 : 0 : 0 : 0 : 0 : 0 : 500If any 16-bit segment has fewer than four hexadecimal digits, it is assumed that the missing digits are leading zeroes.
23Rule 2: Double colon :: equals 0000…0000 The second rule can reduce this address even further:Any single, contiguous string of one or more 16-bit segments consisting of all zeroes can be represented with a double colon.FE80 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0001FE80 : : 1FE80::1Second RuleFirst Rule
24Rule 2: Double colon :: equals 0000…0000 Only a single contiguous string of all-zero segments can be represented with a double colon.Both of these are correct…FE80 : 0000 : 0000 : 0000 : 0014 : 0000 : 0000 : 0095FE80 :: : 0 : 0 : 95ORFE80 : 0 : 0 : 0 : 14 ::
25Rule 2: Double colon :: equals 0000…0000 Using the double colon more than once in an IPv6 address can create ambiguity because of the ambiguity in the number of 0’s.FE80::14::95FE80:0000:0000:0000:0014:0000:0000:0095FE80:0000:0000::0014:0000: :0095FE80:0000:0014:0000:0000:0000:0000:0095
26Network PrefixesIPv4, the prefix—the network portion of the address—can be identified by a dotted decimal netmask or bitcount.or /24IPv6 prefixes are always identified by bitcount (prefix length).Prefix length notation:2001:0DB8:100:a::/64bitsThe address is followed by a forward slash and a decimal number indicating how many of the first bits of the address are the prefix bits.
29Global Unicast Address (GUA) Global Routing PrefixSubnet IDInterface IDRange: 2000::/ ::to 3FFF::/ ::001IANA’s allocation of IPv6 address space in 1/8th sectionsGlobal unicast addresses are similar to IPv4 addressesRoutableUnique
30Global Unicast Address (GUA) Global Routing PrefixSubnet IDInterface IDRange: 2000::/ ::to 3FFF::/ ::001Global unicast addresses are equivalent to IPv4 public addressesExcept under very specific circumstances, all end users will have a global unicast addressTerminology:Prefix equivalent to network addressPrefix length equivalent to subnet mask in IPv4Interface ID equivalent to host portion
31Typical Global Unicast Address and Why We Love IPv6! IPv4 Unicast Address/?Network portionSubnet portionHost portion32 bitsIPv6 Global Unicast Address/48/6416-bit Fixed Subnet IDGlobal Routing PrefixInterface ID128 bits64-bit Interface ID = 18 quintillion (18,446,744,073,709,551,616) devices/subnet16-bit Subnet ID = 65,536 subnets
33Subnetting IPv6 and Why Our Students Will Love IPv6 Just increment by 1 in Hexadecimal:2001:0DB8:AAAA:0000::/642001:0DB8:AAAA:0001::/642001:0DB8:AAAA:0002::/642001:0DB8:AAAA:000A::/64Valid abbreviation is to remove the 3 leading 0’s from the first shown quartet2001:0DB8:AAAA:1::/643-1-4 Rule
35Subnetting on a nibble boundary /48/6860 bits48 bits20 bitsGlobal Routing PrefixSubnet IDInterface ID/68 PrefixSubnetting on a nibble (4 bit) boundary makes it easier to list the subnets:/64, /68, /72, etc.2001:0DB8:AAAA:0000:0000::/682001:0DB8:AAAA:0000:1000::/682001:0DB8:AAAA:0000:2000::/68 through2001:0DB8:AAAA:FFFF:F000::/68/68
36Subnetting within a nibble /48/7048 bits22 bits58 bitsGlobal Routing PrefixSubnet IDInterface ID/70 PrefixFour Bits: The two leftmost bits are part of the Subnet-ID, whereas the two rightmost bits belong to the Interface ID.2001:0DB8:AAAA:0000:0000::/2001:0DB8:AAAA:0000:0400::/2001:0DB8:AAAA:0000:0800::/2001:0DB8:AAAA:0000:0C00::/bits
37Do we need the IPv6 equivalent to a /30? /127? /48/12748 bits79 bits1bitGlobal Routing PrefixSubnet ID127-bit Prefix1 bit Interface IDBeyond the scope of CCNA but may be of interest….RFC Using 127-Bit IPv6 Prefixes on Inter-Router LinksPing-Pong AttackNeighbor Cache Exhaustion IssueThere are mitigation techniques for both.If you still want to use a /127, reserve a separate /64 for each /127.2001:0DB8:AAAA:F000::/642001:0DB8:AAAA:F000::A/1272001:0DB8:AAAA:F000::B/1272001:0DB8:AAAA:F001::/642001:0DB8:AAAA:F001::A/1272001:0DB8:AAAA:F001::B/127
39Stateless Autoconfiguration Configuring a Global Unicast AddressGlobal UnicastManualDynamicIPv6 UnnumberedStateless AutoconfigurationIPv6 AddressDHCPv6StaticEUI-64
40Exactly the same as an IPv4 address only different. R1(config)#interface gigabitethernet 0/0R1(config-if)#ipv6 address 2001:db8:acad:1::1/64R1(config-if)#no shutdownR1(config-if)#exitNo spaceExactly the same as an IPv4 address only different.No space between IPv6 address and Prefix-length.IOS commands for IPv6 are very similar to their IPv4 counterpart.All 0’s and all 1’s are valid IPv6 host IPv6 addresses.
42show running-config command on router R1 R1# show running-config<output omitted for brevity>interface GigabitEthernet0/0no ip addressduplex autospeed autoipv6 address 2001:DB8:ACAD:1::1/64!
43show ipv6 interface brief command on router R1 R1# show ipv6 interface briefGigabitEthernet0/0 [up/up]FE80::FE99:47FF:FE75:C3E02001:DB8:ACAD:1::1Link-local unicast addressGlobal unicast addressLink-local address automatically created when (before) the global unicast address is.We will discuss link-local addresses soon.
44PC1: Static Global Unicast Address 2001:db8:acad:1::10642001:db8:acad:1::1 (or link-local address)
45PC1: Static Global Unicast Address PC1> ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : IPv6 Address : 2001:db8:acad:1::10 Link-local IPv6 Address : fe80::50a5:8a35:a5bb:66e1 Default Gateway : 2001:db8:acad:1::1
46Pinging a Global Unicast IPv6 Addresses Ping uses ICMPv6 Echo Request and Echo Reply messages similar to ICMPv4.PC1> ping 2001:db8:acad:1::1Pinging 2001:db8:acad:1::1 from 2001:db8:acad:1::100 with 32 bytes of data:Reply from 2001:db8:acad:1::1: time=1msPing statistics for 2001:db8:acad:1::1:Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),Approximate round trip times in milli-seconds:Minimum = 1ms, Maximum = 1ms, Average = 1msPC1>
50With IPv6 it begins with the Router Advertisement To all IPv6 routers: I need IPv6 address informationICMPv6 Router SolicitationDHCPv6 ServerTo all IPv6 devices:Let me tell you how to do this …ICMPv6 Router AdvertisementICMPv6 Neighbor DiscoveryRouter SolicitationRouter AdvertisementThe Router Advertisement (RA) tells hosts how it will receive IPv6 Address Information.Sent periodically by an IPv6 router or…… when the router receives a Router Solicitation message from a host.
51ICMPv6 Router Advertisement R1(config)# ipv6 unicast-routingDHCPv6 ServerRouter Advertisement/Solicitation MessagesPart of ICMPv6 (Internet Control Message Protocol for IPv6)Router Advertisements (RA) are sent by an “IPv6 router” – ipv6 unicast-routing commandForwards IPv6 PacketsCan be enabled for IPv6 static and dynamic routingSends ICMPv6 Router AdvertisementsNote: Routers can be configured with IPv6 addresses without being an IPv6 router
52SLAAC (Stateless Address Autoconfiguration) Option 1 and 2: Stateless Address Autconfiguration – DHCPv6 Server does not maintain state of addressesOption 3: Stateful Address Configuration – Address received from DHCPv6 ServerDHCPv6R1(config)# ipv6 unicast-routingDHCPv6 ServerOption 1: SLAAC (Default on Cisco routers)“I’m everything you need (Prefix, Prefix-length, Default Gateway)”Option 2: SLAAC + Stateless DHCPv6 for DNS address“Here is my information but you need to get other information such as DNS addresses from a DHCPv6 server.”Option 3: All addressing except default gateway – DHCPv6“I can’t help you. Ask a DHCPv6 server for all your information.”RA
53Router Advertisement – Option 1 SLAAC 2001:DB8:ACAD:1::/64MAC: B-8C-E0-801Option 1 – RA MessageTo: FF02::1 (All IPv6 devices multicast – more later)From: FE80::1 (Link-local address)Prefix: 2001:DB8:ACAD:1::Prefix-length: /642RAPrefix: 2001:DB8:ACAD:1::Prefix-length: /64Default Gateway: FE80::1Global Unicast Address:2001:DB8:ACAD:1: + Interface ID3EUI-64 Process or Random 64-bit valueDHCPv6 Server
54Dynamic Interface ID Router Advertisement 2001:DB8:ACAD:1::/64 DHCPv6 Server/48/6464 bitsGlobal Routing PrefixSubnet IDInterface IDSLAACEUI-64 ProcessRandomly Generated Number(Privacy Extension)Windows operating systems, Windows XP and Server 2003 use EUI-64.Windows Vista and newer; hosts create a random 64-bit Interface ID.Linux: Mostly use random 64-bit numberMac OSX: use EUI-64 (on my Macs)
55EUI-64 (Extended Unique Identifier – 64) 2001:DB8:ACAD:1::/64MAC: B-E9-D4-801Option 1 – RA MessageTo: FF02::1 (All IPv6 devices multicast)From: FE80::1 (Link-local address)Prefix: 2001:DB8:ACAD:1::Prefix-length: /642RAPrefix: 2001:DB8:ACAD:1::Prefix-length: /64Default Gateway: FE80::1Global Unicast Address:2001:DB8:ACAD:1: + Interface IDEUI-64 Process or Random 64-bit valueDHCPv6 Server
56EUI-64 F F F E 00 03 6B E9 D4 80 02 03 6B FF FE E9 D4 80 OUI 24 bits Device Identifier24 bitsHexadecimal00036BE9D480Step 1: Split the MAC addressBinaryF F F EStep 2: Insert FFFEBinaryStep 3: Flip the U/L bitBinaryModified EUI-64 Interface ID in Hexadecimal Notation02036BFFFEE9D480Binary
57PC1: Global Unicast Address Router AdvertisementEUI-64PC1> ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : IPv6 Address : 2001:db8:acad:1: b-ff-fe-e9-d4-80 Link-local IPv6 Address : fe80:: b-ff-fe-e9-d4-80 Default Gateway : fe80::1A 64-bit Interface ID and the EUI-64 process accommodate the IEEE specification for a 64-bit MAC address.
58Option 2:Stateless DHCPv6 I created my own address,have a prefix-length, default gateway, but I need a DNS address…ICMPv6Router AdvertisementDHCPv6DHCPv6 ServerOther Configuration Flag is set.Use me for your address information just like SLAAC but…… you need to get other information from a DHCPv6 server like possibly a DNS server address.Learn how to configure the RA message and the Stateless DHCPv6 server in the Intermediate IPv6 presentation
59Option 3: Stateful DHCPv6 The router’s Router Advertisement tells me it can’t help me and I need to communicate with a stateful DHCPv6 server…ICMPv6Router AdvertisementDHCPv6DHCPv6 ServerManaged Configuration Flag is set.Get ALL of your address information from a DHCPv6 server except use my link-local address for your default gateway address.Learn how to configure the RA message and the Stateful DHCPv6 server in the Intermediate IPv6 presentation
60What about Stateful DHCPv6? DHCPv6 is similar to DHCPv4.Host operating systems “may” include the option of ignoring the Router Advertisement from the router and only use the stateful services of a DHCPv6 server.Note: All addresses should be checked before use with DAD (Duplicate Address Detection), similar to gratuitous ARP in IPv4.DHCPv6DHCPv6 Server
61The World of IPv4 – DHCPv4 and NAT G0/1G0/1HOMEG0/0ISPDHCPv4Public IPv4 Addressfor the interfacePrivate IPv4 AddressDHCPv4/8/12/16What about DHCP and IPv6 for my home network – First IPv4 at home….ISP only has to deliver a public IPv4 address for Home router interface.DHCP and RFC 1918 private address space is used for home network (ISP is not involved).NAT is used for translation – but has its drawbacks!No NAT (like that… kind of) for IPv6
62The World of IPv6 – DHCPv6-PD (Prefix Delegation) Complete IPv6 ReachabilityDelegating Router (DR)Requesting Router (RR)G0/1G0/1G0/0ISP-DRHOME-RRHow does the home network get a “pubic” IPv6 address?IPv6 Address for the interface:SLAACDHCPv6 (Stateful or Stateless)DHCPv6 with Prefix DelegationIn the Intermediate presentation we will learn the operations and configuration of DHCPv6-PD.
65Link-Local Communications Link-local unicastLink-Local CommunicationsUsed to communicate with other devices on the link.Are NOT routable off the link (network).Only have to be unique on the link.Are not included in the IPv6 routing table.An IPv6 device must have at least a link-local address.Used by:Hosts to communicate to the IPv6 network before it has a global unicast address.Router’s link-local address is used by hosts as the default gateway address.Adjacent routers to exchange routing updates
66Link-local Unicast Interface ID FE80::/10 10 bitsRemaining 54 bits64 bits/64xx xxxxInterface IDFE80::/10EUI-64, Random or Manual ConfigurationRange: FE80::/ ::to FEBF::/ ::
67IOS uses EUI-64 to Create Link-Local Addresses Wait! Two Link-Locals are the same!G0/0S0/0/0R1G0/1R1#show interface gigabitethernet 0/0GigabitEthernet0/0 is up, line protocol is upHardware is CN Gigabit Ethernet, address is fc c3e0 (bia fc c3e0)<Output Omitted>R1#show ipv6 interface briefGigabitEthernet0/0 [up/up]FE80::FE99:47FF:FE75:C3E02001:DB8:ACAD:1::1GigabitEthernet0/1 [up/up]FE80::FE99:47FF:FE75:C3E12001:DB8:ACAD:2::1Serial0/0/ [up/up]2001:DB8:ACAD:3::1R1#EUI-64FF:FE = EUI-64 (most likely)Serial interfaces will use a MAC address of an Ethernet interface.
68PC1: Link-Local Unicast Address PC1> ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix .: IPv6 Address : 2001:db8:acad:1:3496:1c51:3f57:fe89 Link-local IPv6 Address : fe80::3496:1c51:3f57:fe89 Default Gateway : fe80::1Many operating systems will use a random 64-bit Interface IDs for GUA and Link- Local IPv6 Addresses.
69Configuring Static Link-Local Addresses G0/0 FE80::1S0/0/0FE80::1G0/1FE80::1R1Static addresses are more easily remembered and recognizable.R1(config)#interface gigabitethernet 0/0R1(config-if)#ipv6 address fe80::1 ?link-local Use link-local addressR1(config-if)#ipv6 address fe80::1 link-localR1(config-if)#exitR1(config)#interface gigabitethernet 0/1R1(config)#interface serial 0/0/0R1(config-if)#Link-Local Addresses only have to be unique on the link!
70ipv6 enable commandRouter(config)# interface gigabitethernet 0/1Router(config-if)# ipv6 enableRouter(config-if)# endRouter# show ipv6 interface briefGigabitEthernet0/ [up/up]FE80::20C:30FF:FE10:92E1Router#Link-local unicast address onlyLink-local addresses are automatically created whenever a global unicast address is configuredThe ipv6 enable command will:Create a link-local address when there is no global unicast addressMaintain the link-local address even when the global unicast address is removed
71Pinging a Link-Local Address FE80::1FE80::2R1Ser 0/0/0:1Ser 0/0/0:2R2FE80::12001:0DB8:ACAD:2::/642001:0DB8:ACAD:1::/64G0/0R1# ping fe80::2Output Interface: ser 0/0/0% Invalid interface. Use full interface name without spaces (e.g. Serial0/1)Output Interface: serial0/0/0Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to FE80::2, timeout is 2 secs:!!!!!Must include exit-interface
72Next-hop addresses in IPv6 Routing Tables R1# show ipv6 route ospfO :DB8:CAFE:2::/64 [110/657]via FE80::2, Serial0/0/0O :DB8:CAFE:3::/64 [110/1304]O :DB8:CAFE:A002::/64 [110/1294]R1#Link-local addresses are used as next hop addresses
75IPv6 Multicast Similar to Multicast addresses for IPv4. 8 bits4 bits4 bits112bitsFlagScopeGroup IDFF00::/8Similar to Multicast addresses for IPv4.Used to send a packet to a group of devices.Two types:AssignedSolicited Node
76Assigned Multicast Addresses FE80::1FF02::1ICMPv6 Router AdvertisementFF02::1 – All IPv6 DevicesAll IPv6 devices, including the router, belong to this group.Every IPv6 device will listen and process packets to this address.
77Assigned Multicast Addresses FE80::0123:456:789A:BCDEFF02::2R1(config)# ipv6 unicast-routingICMPv6 Router SolicitationFF02::2 – All IPv6 RoutersAll IPv6 routers belong to this group.Used to communicate with an IPv6 Router (ipv6 unicast routing)
78Multicast Groups of a Router R1# show ipv6 interface gigabitethernet 0/0FastEthernet0/0 is up, line protocol is upIPv6 is enabled, link-local address is FE80::FE99:47FF:FE75:C3E0Global unicast address(es):2001:DB8:ACAD:1::1, subnet is 2001:DB8:ACAD:1::/64Joined group address(es):FF02::1FF02::2FF02::5FF02::6FF02::1:FF00:1FF02::1:FF75:C3E0<output omitted for brevity>Member of these Multicast GroupsAll-IPv6 devices on this linkAll-IPv6 routers on this link: IPv6 routing enabledOSPFv3 All OSPF Routers (similar to )OSPFv3 All DR Routers (similar to )Solicited-node multicast addressesFF02 – “2” means link-local scopeWhat is a solicited node multicast address? Let’s talk address resolution.
80Address Resolution: IP to MAC Mapping Know IPv4, what is the MAC?My IPv4! Here is the MAC?21ARP ReplyARP RequestPC1PC2ARP Cache31My IPv6! Here is the MAC?2Neighbor AdvertisementNeighbor SolicitationKnow IPv6, what is the MAC?NeighborCache3IP to data link(MAC) address mapping:IPv4 addresses use ARPIPv6 addressing use ICMPv6 Neighbor Discovery messagesNeighbor SolicitationNeighbor AdvertisementDevices store this mapping in their Neighbor CacheICMPv6 Neighbor DiscoveryNeighbor SolicitationNeighbor Advertisement
81Address Resolution: IP to MAC Mapping IPv4: ARP over EthernetEthernetARP Request/ReplyARP Request: BroadcastKnow IPv4, what is the MAC?My IPv4! Here is the MAC?21ARP ReplyARP RequestPC1PC21My IPv6! Here is the MAC?2Know IPv6, what is the MAC?Neighbor AdvertisementNeighbor SolicitationIPv6: ICMPv6 over IPv6 over EthernetEthernetIPv6 HeaderICMPv6: Neighbor Solicitation/AdvertisementNS: MulticastNS: Solicited Node Multicast
82Advantages of Multicast Ethernet BroadcastDestination MAC Address: BroadcastData must be passed to upper layer for processing.IPv4 or IPv6 MulticastIP multicast packets can be filtered by the switch, only sending packets to members of that groupIPv4 - IGMP (Internet Group Management Protocol)IPv6 - MLD (Multicast Listener Discovery)However, Solicited Node Multicasts are forwarded out all ports because of the potentially huge forwarding tables needed to to store these addresses. (For now.)Ethernet BroadcastSolicited Node multicast addressesto be sent to every port to improve network robustment andmanagement.IPv6 Addressing Architecture requires that all nodes must join theassociated Solicited-Node multicast addresses for every unicast andanycast address it is assigned. This causes MLD snooping switches tocreate potentially huge multicast forwarding tables just to handleNeighbor Discovery. A simple change to alleviate this would be toallow switches to forward a range of addresses that include theSolicited-Node multicast addresses to every port. This also couldhelp in network discovery.IPv4/IPv6 MulticastIGMP/MLD Snooping
83Why layer 2 multicast? ARP Requests: Layer 2 broadcasts: Ethernet broadcasts are sent to all devices.Flood the entire broadcast domain (subnet/VLAN).Ethernet NIC must process the frame.Any filtering is done by a higher layer protocol such as ARP.Target IPv4AddressSolicited Node Multicasts: Layer 2 and Layer 3 multicasts:Although solicited node multicasts are forwarded out all ports, ….Layer 2 multicast allows frames to be filtered by the NIC and not have send data to an upper layer protocol for inspection.
84Neighbor Cache (IPv4 ARP Cache) Neighbor AdvertisementNeighbor CacheIPv6 Address MAC Address2001:DB8:ACAD:1:: bd9.c644PC1IPv :DB8:ACAD:1::10MAC bd9.c644Neighbor Cache – Maps IPv6 addresses with Ethernet MAC addressesSimilar to ARP Cache for IPv45 States (2 noticeable and 3 transitory): (My CCNP Presentation)Reachable: Packets have recently been received providing confirmation that this device is reachable.Stale: A certain time period has elapsed since a packet has been received from this address.Transitory States: INCOMPLETE, DELAY, PROBE
85Neighbor Cache Windows: netsh interface ipv6 show neighbor Linux/MAC: ip neighbor showR1# show ipv6 neighborsIPv6 Address Age Link-layer Addr State InterfaceFE80::50A5:8A35:A5BB:66E bd9.c644 STALE Fa0/02001:DB8:ACAD:1:: bd9.c644 STALE Fa0/0R1# ping 2001:db8:aaaa:1::100Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 2001:DB8:AAAA:1::100, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms2001:DB8:ACAD:1:: bd9.c644 REACH Fa0/0R1#AgeTime (in minutes) since the address was confirmed to be reachable. A hyphen (-) indicates a static entry.
87Internet Control Message Protocol (ICMPv6) IPv6 Next Header Value: 58 decimal or 3A hexadecimalICMPv6 HeaderICMPv6 Message BodyNext Header58IPv6 HeaderIPv6 DataDescribed in RFC 4443Much more robust than ICMP for IPv4Contains new functionality and improvements.More than just “messaging” but “how IPv6 conducts business”.General message similar to ICMP for IPv4Also uses Type and Code fields like in ICMPv4.
88Neighbor Discovery Protocol Uses ICMPv6 ICMPv6 informational messages used by Neighbor Discovery (RFC 4861):Router Solicitation MessageRouter Advertisement MessageDiscussed with dynamic configuration of IPv6 addressesIntroduced with assigned multicast addressesNeighbor Solicitation MessageNeighbor Advertisement MessageDiscussed with address resolution (IPv4 ARP)Introduced with solicited node multicast addressRedirect Message (Similar to ICMPv4)Router-Device MessagingDevice-Device Messaging
89Router Solicitations and Router Advertisements Used by SLAAC (Stateless Address Autoconfiguration)1Router Solicitation MessageI need IPv6 address information.FF02::2All IPv6 RoutersPC1DHCPv6 ServerRouter Advertisement MessageHere is one of three options:I have everything you need.I have mostly what you need, but you will need to contact a DHCPv6 server for other information like a DNS address.I have nothing for you. Contact a DHCPv6 serverl2FF02::1All IPv6 Devices
90Neighbor Solicitations and Neighbor Advertisements Neighbor Solicitation MessageWhoever has the IPv6 Address 2001:DB8:ACAD:1::10 please send me your Ethernet MAC address.1PC2Solicited Node MulticastPC12Neighbor Advertisement MessageI have the IPv6 Address 2001:DB8:ACAD:1::10. Here is my Ethernet MAC address:0021:9bd9:c644.UnicastAddress Resolution - A device knows the IPv6 address but needs the Layer 2 MAC address.Unlike ARP, ICMPv6 Neighbor Solicitation/Advertisement messages are encapsulated in IPv6.Information is stored in the Neighbor Cache.
91Teach it and use it, and it will all make sense! What we covered…Why IPv6?IPv6 and ICMPv6 at a glanceFormat of an IPv6 AddressIPv6 AddressGlobal Unicast IPv6 AddressSubnettingLink-Local Unicast IPv6 AddressStatic Configuration of a Global Unicast AddressDynamic Configuration of a Global Unicast AddressThree optionsLink-local addressMulticast addressAddress ResolutionTeach it and use it, and it will all make sense!
92Quality time with my two nieces… Web Site, Book, Etc.Shameless plug!Rick Graziani -PowerPoints for CCNA, CCNP, IPv6Username = ciscoPassword = perlmanQuality time with my two nieces…
93And…… Thank you very much! Rick Graziani - Username = cisco Password = perlman