620 likes | 1.27k Views
IPv6 Fundamentals Chapter 4: IPv6 Address Types. Rick Graziani Cabrillo College graziani@cabrillo.edu Fall 2013. IPv6 Addresses. IPv6 Addressing. Anycast. Multicast. Unicast. Assigned. Solicited Node. FF00::/8. FF02::1:FF00:0000/104. Embedded IPv4. Unique Local. Unspecified.
E N D
IPv6 FundamentalsChapter 4: IPv6 Address Types Rick Graziani Cabrillo College graziani@cabrillo.edu Fall 2013
IPv6 Addressing Anycast Multicast Unicast Assigned Solicited Node FF00::/8 FF02::1:FF00:0000/104 Embedded IPv4 Unique Local Unspecified Global Unicast Link-Local Loopback 2000::/3 3FFF::/3 ::/128 FE80::/10 FEBF::/10 ::1/128 ::/80 FC00::/7 FDFF::/7
Global Unicast Address (GUA) Global Routing Prefix Subnet ID Interface ID Range: 2000::/3 0010 0000 0000 0000 :: to 3FFF::/3 0011 1111 1111 1111 :: 001 IANA’s allocation of IPv6 address space in 1/8th sections • Global unicast addresses are similar to IPv4 addresses • Routable • Unique
R1(config)#interface gigabitethernet 0/1 R1(config-if)#ipv6 address 2001:db8:acad:2::1/64 R1(config-if)#no shutdown R1(config-if)#exit R1(config)#interface serial 0/0/0 R1(config-if)#ipv6 address 2001:db8:acad:3::1/64 R1(config-if)#clock rate 56000 R1(config-if)#no shutdown
show running-config command on router R1 R1# show running-config <output omitted for brevity> interface GigabitEthernet0/0 no ip address duplex auto speed auto ipv6 address 2001:DB8:ACAD:1::1/64 !
show ipv6 interface brief command on router R1 R1# show ipv6 interface brief GigabitEthernet0/0 [up/up] FE80::FE99:47FF:FE75:C3E0 2001:DB8:ACAD:1::1 Link-local unicast address Global unicast address • Link-local address automatically created when (before) the global unicast address is. • We will discuss link-local addresses next.
PC1: Static Global Unicast Address 2001:db8:acad:1::10 64 2001:db8:acad:1::1
Configuring Dynamic IPv6 Addresses Global Unicast Manual Dynamic Stateless Autoconfiguration IPv6 Unnumbered IPv6 Address DHCPv6 Static EUI-64
IPv4 Dynamic Addresses DHCP Server
With IPv6 it begins with the Router Advertisement • The 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.
Router Advertisement Router Advertisement/Solicitation Messages • Part of ICMPv6 (Internet Control Message Protocol for IPv6) • Router Advertisements are sent by an “IPv6 router” – ipv6 unicast-routing command • Forwards IPv6 Packets • Can be enabled for IPv6 static and dynamic routing • Sends ICMPv6 Router Advertisements • Routers can be configured with IPv6 addresses without being an IPv6 router R1(config)# ipv6 unicast-routing DHCPv6 Server
SLAAC (Stateless Address Autoconfiguration) • Option 1 and 2: Stateless Address Autconfiguration– DHCPv6 Server does not maintain state of addresses • Option 3: Stateful Address Configuration – Address received from DHCPv6 Server DHCPv6 R1(config)# ipv6 unicast-routing DHCPv6 Server Option 1 (Default on Cisco routers) “I’m everything you need (Prefix, Prefix-length, Default Gateway)” Option 2 (Discussed in CCNA Switching) “Here is my information but you need to get other information such as DNS addresses from a DHCPv6 server.” Option 3 (Discussed in CCNA Switching) “I can’t help you. Ask a DHCPv6 server for all your information.” RA
Router Advertisement – Option 1 MAC: 00-03-6B-8C-E0-80 2001:DB8:ACAD:1::/64 1 Option 1 – RA Message To: FF02::1 (All IPv6 devices multicast) From: FE80::1 (Link-local address) Prefix: 2001:DB8:ACAD:1:: Prefix-length: /64 2 RA Prefix: 2001:DB8:ACAD:1:: Prefix-length: /64 Default Gateway: FE80::1 Global Unicast Address: 2001:DB8:ACAD:1:+ Interface ID 3 EUI-64 Process or Random 64-bit value DHCPv6 Server
Dynamic Interface ID Router Advertisement 2001:DB8:ACAD:1::/64 DHCPv6 Server • 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 number • Mac OSX: use EUI-64 (on my Macs) /48 /64 64 bits Subnet ID Global Routing Prefix Interface ID SLAAC EUI-64 Process Randomly Generated Number
EUI-64 (Extended Unique Identifier – 64) MAC: 00-03-6B-E9-D4-80 2001:DB8:ACAD:1::/64 1 Option 1 – RA Message To: FF02::1 (All-hosts multicast) From: FE80::1 (Link-local address) Prefix: 2001:DB8:ACAD:1:: Prefix-length: /64 2 RA Prefix: 2001:DB8:ACAD:1:: Prefix-length: /64 Default Gateway: FE80::1 Global Unicast Address: 2001:DB8:ACAD:1:+ Interface ID EUI-64 Process or Random 64-bit value DHCPv6 Server
OUI 24 bits Device Identifier 24 bits EUI-64 Hexadecimal 00 03 6B E9 D4 80 Step 1: Split the MAC address 0000 0000 0000 0011 0110 1011 1110 1001 1101 0100 1000 0000 Binary F F F E Step 2: Insert FFFE 1110 1001 1101 0100 1000 0000 1111 1111 0000 0000 0000 0011 0110 1011 1111 1110 Binary Step 3: Flip the U/L bit 0000 0010 0000 0011 0110 1011 1111 1111 1110 1001 1101 0100 1000 0000 1111 1110 Binary Modified EUI-64 Interface ID in Hexadecimal Notation FF FE 02 03 6B E9 D4 80 Binary
PC1: Global Unicast Address PC1> ipconfig Windows IP Configuration Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : IPv6 Address. . . . . . . . . . . : 2001:db8:acad:1:02-03-6b-ff-fe-e9-d4-80 Link-local IPv6 Address . . . . . : fe80::02-03-6b-ff-fe-e9-d4-80 Default Gateway . . . . . . . . . : fe80::1 Router Advertisement EUI-64 • A 64-bit Interface ID and the EUI-64 process accommodate the IEEE specification for a 64-bit MAC address.
What about Stateful DHCPv6? (CCNA Switching) • 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. DHCPv6 DHCPv6 Server
IPv6 Addressing Anycast Multicast Unicast Assigned Solicited Node FF00::/8 FF02::1:FF00:0000/104 Embedded IPv4 Unique Local Unspecified Global Unicast Link-Local Loopback 2000::/3 3FFF::/3 ::/128 FE80::/10 FEBF::/10 ::1/128 ::/80 FC00::/7 FDFF::/7
Link-local Unicast 64 bits Remaining 54 bits 10 bits /64 1111 1110 10xx xxxx Interface ID EUI-64, Random or Manual Configuration FE80::/10 Range: FE80::/10 1111 1110 1000 0000 :: to FEBF::/10 1111 1110 1011 1111 ::
Link-local unicast Link-Local Communications • Used 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
Wait!Two Link-Locals are the same! G0/0 IOS uses EUI-64 to Create Link-Local Addresses S0/0/0 R1 G0/1 R1#show interface gigabitethernet 0/0 GigabitEthernet0/0 is up, line protocol is up Hardware is CN Gigabit Ethernet, address is fc99.4775.c3e0 (bia fc99.4775.c3e0) <Output Omitted> R1#show ipv6 interface brief GigabitEthernet0/0 [up/up] FE80::FE99:47FF:FE75:C3E0 2001:DB8:ACAD:1::1 GigabitEthernet0/1 [up/up] FE80::FE99:47FF:FE75:C3E1 2001:DB8:ACAD:2::1 Serial0/0/0 [up/up] FE80::FE99:47FF:FE75:C3E0 2001:DB8:ACAD:3::1 R1# EUI-64 FF:FE = EUI-64 (most likely) Serial interfaces will use a MAC address of an Ethernet interface.
PC1: 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::1 • Many operating systems will use a random 64-bit Interface IDs for GUA and Link-Local IPv6 Addresses.
G0/0 FE80::1 Configuring Static Link-Local Addresses S0/0/0 FE80::1 R1 G0/1 FE80::1 Static addresses are more easily remembered and recognizable. R1(config)#interface gigabitethernet 0/0 R1(config-if)#ipv6 address fe80::1 ? link-local Use link-local address R1(config-if)#ipv6 address fe80::1 link-local R1(config-if)#exit R1(config)#interface gigabitethernet0/1 R1(config-if)#ipv6 address fe80::1 link-local R1(config-if)#exit R1(config)#interface serial 0/0/0 R1(config-if)#ipv6 address fe80::1 link-local R1(config-if)# Link-Local Addresses only have to be unique on the link!
ipv6 enable command Router(config)# interface gigabitethernet 0/1 Router(config-if)# ipv6 enable Router(config-if)# end Router# show ipv6 interface brief GigabitEthernet0/1 [up/up] FE80::20C:30FF:FE10:92E1 Router# Link-local unicast address only • Link-local addresses are automatically created whenever a global unicast address is configured • The ipv6 enable command will: • Create a link-local address when there is no global unicast address • Maintain the link-local address even when the global unicast address is removed
Pinging a Link-Local Address FE80::1 FE80::2 R1 R2 Ser 0/0/0 :1 Ser 0/0/0 :2 FE80::1 2001:0DB8:ACAD:2::/64 2001:0DB8:ACAD:1::/64 G0/0 R1# ping fe80::2 Output Interface: ser 0/0/0 % Invalid interface. Use full interface name without spaces (e.g. Serial0/1) Output Interface: serial0/0/0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to FE80::2, timeout is 2 secs: !!!!! Must include exit-interface
IPv6 Multicast IPv6 Addressing Anycast Multicast Unicast Assigned Solicited Node FF00::/8 FF02::1:FF00:0000/104
IPv6 Multicast 4 bits 4 bits 8 bits 112bits • Similar to Multicast addresses for IPv4. • Used to send a packet to a group of devices. Two types: • Assigned • Solicited Node Group ID 1111 1111 Flag Scope FF00::/8
Assigned Multicast Addresses • FF02::1 – All IPv6 Devices • All IPv6 devices, including the router, belong to this group. • Every IPv6 device will listen and process packets to this address.
Assigned Multicast Addresses FE80::0123:456:789A:BCDE FF02::2 • FF02::2 – All IPv6 Routers • All IPv6 routers belong to this group. • Used to communicate with an IPv6 Router (ipv6 unicast routing) R1(config)# ipv6 unicast-routing
Multicast Groups of a Router R1# show ipv6 interface gigabitethernet 0/0 FastEthernet0/0 is up, line protocol is up IPv6 is enabled, link-local address is FE80::FE99:47FF:FE75:C3E0 Global unicastaddress(es): 2001:DB8:ACAD:1::1, subnet is 2001:DB8:ACAD:1::/64 Joined group address(es): FF02::1 FF02::2 FF02::1:FF00:1 FF02::1:FF75:C3E0 <output omitted for brevity> Member of these Multicast Groups All-IPv6 devices on this link All-IPv6 routers on this link: IPv6 routing enabled Solicited-node multicast address for Global Address Solicited-node multicast address for Link-local Unicast Address • FF02 – “2” means link-local scope • What is Solicited node?
Solicited Node Multicast Address (Introduction) PC2 PC1 Destination: Solicited-node Multicast “Who ever has the IPv6 address 2001:DB8:ACAD:1::10 please send me your Ethernet MAC address” Solicited Node Multicast Address • Used as a destination address when don’t know the unicast address. • Typically used as the destination IPv6 address with: • Address Resolution (“IPv4 ARP”) • Duplicate Address Detection (“Gratuitous ARP”) • Same intent as a broadcast but more efficient. • Devices process packets with their solicited node multicast address as the destination address: IP and MAC.
Solicited Node Multicast – It’s not pretty but it’s simple Global Unicast Address Interface ID Global Routing Prefix Subnet ID 24 bits 104 bits 2001:0DB8:ACAD 0001 0000:0000:00 00:0010 The last 24 bits match. Copy Solicited-Node Multicast Address 104 bits FF02 0000 0000 0000 0000 0001 FF 00:0010 The simple The ugly IPv6 Global Unicast Address: 2001:0DB8:ACAD:0001:0000:0000:0000:0010 IPv6 Solicited Node Multicast Address: FF02::1:FF00:0010
Solicited Node Multicast – Used in Address Resolution • AllIPv6 Devices Multicast: FF02::1 • Link-Local Address: FE80::02-03-6B-FF-FE-8C-E0-80 • Global Unicast Address: 2001:DB8:ACAD:1::10 • Solicited Node MulticastAddress: FF02::1:FF00:0010 I listen for several IPv6 addresses! PC2 PC1 Destination: Solicited-node Multicast FF02::1:FF00:0010 “Who ever has the IPv6 address 2001:DB8:ACAD:1::10 please send me your Ethernet MAC address” Note (beyond CCNA): Solicited Node Multicast addresses are also mapped to a special multicast MAC address: 33-33-FF-00-00-10
A Brief look at ICMPv6 (Internet Control Message Protocol for IPv6)
Internet Control Message Protocol (ICMPv6) IPv6 Next Header Value: 58 decimal or 3A hexadecimal • Described in RFC 4443 • Much more robust than ICMP for IPv4 • Contains new functionality and improvements. • More than just “messaging” but “how IPv6 conducts business”. • General message similar to ICMP for IPv4 • Also uses Type and Code fields like in ICMPv4. ICMPv6 Message Body ICMPv6 Header Next Header 58 IPv6 Header IPv6 Data
Neighbor Discovery Protocol Uses ICMPv6 • ICMPv6 informational messages used by Neighbor Discovery (RFC 4861): • Router Solicitation Message • Router Advertisement Message • Neighbor Solicitation Message • Neighbor Advertisement Message • Redirect Message (Similar to ICMPv4) Router-Device Messaging Device-Device Messaging
Router Solicitations and Router Advertisements Used by SLAAC (Stateless Address Autoconfiguration) 1 Router Solicitation Message I need IPv6 address information. FF02::2 All IPv6 Routers PC1 DHCPv6 Server Router Advertisement Message Here 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 serverl 2 FF02::1 All IPv6 Devices
Neighbor Solicitations and Neighbor Advertisements • Address 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. Neighbor Solicitation Message Whoever has the IPv6 Address 2001:DB8:ACAD:1::10 please send me your Ethernet MAC address. 1 PC1 PC2 Solicited Node Multicast Neighbor Advertisement Message I have the IPv6 Address 2001:DB8:ACAD:1::10. Here is my Ethernet MAC address: 0021:9bd9:c644. 2 Unicast
Neighbor Cache Neighbor Cache • Neighbor Cache – Maps IPv6 addresses with Ethernet MAC addresses • Similar to ARP Cache for IPv4 • 5 States (2 noticeable and 3 transitory): • 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 (I will point you to more information) Neighbor Cache IPv6 AddressMAC Address 2001:DB8:ACAD:1::10 0021.9bd9.c644 PC1 IPv6 - 2001:DB8:ACAD:1::10 MAC - 0021.9bd9.c644
Windows: netsh interface ipv6 show neighbor Linux/MAC: ip neighbor show Neighbor Cache R1# show ipv6 neighbors IPv6 Address Age Link-layer Addr State Interface FE80::50A5:8A35:A5BB:66E1 16 0021.9bd9.c644 STALE Fa0/0 2001:DB8:ACAD:1::10 16 0021.9bd9.c644 STALE Fa0/0 R1# ping 2001:db8:aaaa:1::100 Type 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 ms R1# show ipv6 neighbors IPv6 Address Age Link-layer Addr State Interface FE80::50A5:8A35:A5BB:66E1 16 0021.9bd9.c644 STALE Fa0/0 2001:DB8:ACAD:1::10 0 0021.9bd9.c644 REACH Fa0/0 R1#
What we covered… • Why IPv6? (briefly and quickly) • Format of an IPv6 Address • IPv6 Address Types • Global Unicast IPv6 Address • Link-Local Unicast IPv6 Address • Multicast IPv6 Addresses • ICMPv6 – Neighbor Discovery Protocol Teach it and use it, and it will all make sense!
My Afternoon Presentation:IPv6 in CCNA 2 – Routing Protocols • Chapter 1: Routing Concepts • Chapter 2: Static Routing • Chapter 3: Routing Dynamically • Chapter 4: EIGRP • Chapter 5: Advanced EIGRP • Chapter 6: Single Area OSPF • Chapter 7: Advanced Single Area OSPF • Chapter 8: Multi-Area OSPF • Chapter 9: Access Control Lists • Chapter 10: IOS File Management
Shameless plug! Web Site, Book, Etc. • Rick Graziani - graziani@cabrillo.edu • PowerPoints for CCNA, CCNP, IPv6 • www.cabrillo.edu/~rgraziani • Username = cisco • Password = perlman Quality time with my two nieces…