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IPv6 … A Simplified Explanation Presented by Bryan Crisler Senior Network Engineer Time Warner Cable
IPv6 … A Simplified Explanation
Presented by
Bryan Crisler
Senior Network Engineer
Time Warner Cable
Housekeeping
• Take this time to locate:
– Emergency Exits
– Bathrooms
– Breakroom/Water Fountain
– Note taking utensils
• Put your Phones on Vibrate
– If you need to take a call, feel free to step out of the room.
About your Speaker
• Bryan Crisler
– Started in Cable @ Charter Communications, Riverside, CA in June 2005
– Currently a Senior Network Engineer at Time Warner Cable
About your Speaker
• Held following positions:
– Broadband Technician I-IV (Charter)
– Network Operations Specialist (Charter)
– Network Technician (Charter)
– Network Engineer (Charter & TWC)
– SR Network Engineer (TWC)
Today’s Lesson Plan
• Session 1: So What About IPv6?
• Session 2: Every Day IPv6 and You
So What About IPv6?
Session 1
Basic History of IP
• IP – Internet Protocol
• Defined in RFC 791, dated 1981, written by Information Sciences Institute @ USC
• Written for DARPA (Defense Advanced Research Projects Agency)
Basic History of IP
• “… Internet Protocol is designed for use in interconnected systems of packet-switched computer communication networks…provides for transmitting blocks of data called datagrams from sources to destinations… identified by fixed length addresses.” (RFC 791, section 1.1)
Versions of IP
• IPv0 – 3: Experimental Only
• IPv4: Defined in 1981 by RFC 760 & 791. First version to implemented publically. Still in use today.
• IPv5: Also experimental, called Internet Stream Protocol.
• IPv6: Also called IP Next Generation (IPng), Defined in 1998 by RFC 2460-2467
IP Addressing
• Layer 3 (Network) form of Addressing
• Two different forms of IP Address:
– IPv4
• Uses Dotted Decimal (192.168.0.1)
• Has 4,294,967,296 total address (public & private)
• 32 bit address
– IPv6
• Uses Hexadecimal Notation (FE80::1)
• Has 3.4×1038 total address (public & private)
• 128 bit address
IP Addressing – cont.
• Both versions represent a real number
• For Instance:
– 0.0.1.0 = 256
– 10.0.0.4 = 16,777,220
– 0:0:0:0:0:0:0:1 = 1
– 0:0:0:0:1:0:0:0 = 281,462,092,005,375
IP Addressing – cont.
• IPv4 Address:
– Dotted decimal notation
– x.x.x.x, where x is between 0 – 255
• IPv6 Address
– Hexadecimal Number system
– 0000:0000:0000:0000:0000:0000:0000:0000
– Leading Zeros can be removed
– Multiple blocks of zeros can be simplified using colon “:”
IP Addressing – cont.
• Blocks of IPs are called Subnets
• Each Subnet represents a network (either WAN or LAN)
• The range of each subnet is determined by the Subnet Mask
• Each Subnet has a Network (First IP address) and a Broadcast (Last IP Address, IPv4 only) IP Address
• Network Range is calculated Subtracting Subnet Mask and from 255.255.255.255 (IPv4) or by 2^(128 – prefix) (IPv6).
IP Address – cont.
• Network Address: First IP in a Subnet used to identify the entire network
• Broadcast Address (IPv4 only): Last IP in a Subnet used to communicate any device on the Useable IP Range.
• Gateway IP Address: The configured IP address on the next hop router, which contains a path towards a WAN/Internet
• Useable IP Range: Any IP in a subnet except the Network and Broadcast (IPv4 only)
IPv4 Address Example
• A home wireless Router is configured with network address of 192.168.0.0 and a subnet mask of 255.255.255.0
• 255.255.255.255 – 255.255.255.0 = 0.0.0.255 = 256 total addresses
• 192.168.0.0 + 0.0.0.255 = 192.168.0.255 • Network Range: 192.168.0.0 to
192.168.0.255 • Network Address: 192.168.0.0 • Broadcast Address: 192.168.0.255
IPv6 Address Example
• A home wireless router has received a prefix delegated scope from the ISP 2605:e000:160e:816a::/64.
• 2^(128 - prefix) 2^64 -> 18,446,744,073,709,551,616 hosts
• Approximately 18.4 Quintillion IP Addresses.
• If each IP address was the size of a quarter, you could cover the entire earth approximately 24 times.
IPv6 Address Example – cont.
• The network Range is
– 2605:e000:160e:816a:0000:0000:0000:0000 -2605:e000:160e:816a:ffff:ffff:ffff:ffff
• Network Address: 2605:e000:160e:816a:0000:0000:0000:0000
• Broadcast Address: There is no broadcast address, since multicast is used instead.
IPv4 vs IPv6: Comparison
IPv4 IPv6
Address 32-bit 128-bit
Number of Addresses 4,294,967,296 340,282,366,920,938,463,463,374,607,431,76
8,211,456
Network Address X X
Broadcast Address X N/A
Link-Local Range 169.254.0.0/16 FE80::/10
Multicast Range 224.0.0.0 –
239.255.255.255 FF00::/8
Dynamic Addressing DHCP SLAAC or DHCPv6
Security Optional IPSec built-in, optional
Header Length Variable Fixed
IPv4 vs IPv6: Comparison – cont.
IPv4 IPv6
Loopback Address 127.0.0.1/32 ::1/128
Default Gateway 0.0.0.0/0 ::/0
IGP Routing Protocols RIP (v1/v2), OSPF,
ISIS, EIGRP RIPng, OSPFv3,ISIS
EBGP Routing Protocols BGP BGPv4
Other Protocols ICMP, DHCP, DNS ICMPv6, DHCPv6, DNS
IPv6 Features
• Larger Address Space
• Simplified header makes routing more efficient
• Private IP Space not required
• Manual configuration not required due to SLAAC
• Broadcasting of packets replaced with Multicast/Anycast
IPv6 Features – cont.
• Security built into IPv6, but is optional
• Mobility allows for devices to use the same IPv6 Address (from home network) regardless of what network they are connected to.
• Dual Stack / 6 to 4 tunneling is available to provide a smooth transition
ARP vs Neighbor Discovery Protocol • ARP – Address resolution protocol uses IPv4 Broadcast address
to map an IPv4 Address to a MAC address (ARP) or vise versa (rARP).
• Neighbor Discovery Protocol – part of the ICMPv6 protocol, uses multicast to establish communication with devices on the same network segment. Follows the following process: – Neighbor Solicitation: sends a message to FF02::1/16 with
all configured IPv6 addresses – DAD (Duplicate Address Detection): If no message is
received from LAN segment, configured IPv6 Addresses are assumed not to be duplicates.
– Neighbor Assignment: Message sent to confirm configuration of IPv6 addresses to LAN segment.
ARP vs Neighbor Discovery Protocol – cont. • NDP – cont.
– Router Solicitation: message sent to FF02::2/16 to detect presence of routers on network segment. Determine the default gateway for host.
– Router Advertisement: response from router
– Redirect: message sent from router specifying that it is not the best gateway for the host.
SLAAC
• SLAAC – StateLess Address AutoConfiguration
• Allows a host to automatically configure their own IPv6 Address
• Uses NDP to determine a valid Global IPv6 Address
• Uses EUI-64 method
Dynamic Host Configuration Protocol (DHCP) • Allows a DHCP server to assign/configure an
IP Address to an end device
• Will also configure Subnet Mask, Gateway IP, as well as DNS Servers
• When an end device is configured for DHCP, the DORA begins (IPv4) or SARR begins (IPv6).
DHCP – cont.
• DORA (IPv4) – – Discover – Client sends a broadcast message
to DHCP Server – Offer – Server sends a message to client with
an IP Address Offer – Request – Client formally request IP Address
Offered, and sets Subnet Mask, gateway, DNS and lease time
– Acknowledge – Server Acknowledges client Request and reserves IP.
• Once lease is at half-life, DORA process is repeated.
DHCP – cont.
• SARR – Solicit – Client sends a multicast message to
DHCPv6 Server – Advertise – DHCPv6 Server(s) replies to client
with their IPv6 Address – Request – Client formally request IP Address
Offered, and sets Prefix, DNS and lease time, but not gateway (learned from ICMPv6)
– Reply – Server Acknowledges client Request and reserves IP.
• Once lease is at half-life, SARR process is repeated.
Domain Name Service (DNS)
• DNS – Maps a domain name like google.com to an IP Address
• DNS Support for IPv6 has been added
• “AAAA” records are used to map a FQDN like google to an IPv6 Address
• “A” Records are used to map FQDN to an IPv4 Address.
Session 1 Review
• How many bits are in an IPv6 Address?
• What method is used by DHCPv6?
• What does the double colon “::” mean in hexadecimal numbering system for IPv6?
• Does ICMPv6 use broadcast or multicast messages?
• How is a default route or default gateway determined?
Session 1 Q&A
• Any Questions???
Break time
15 Minutes
Every Day IPv6 and You
Session 2
Why did IPv6 become Necessary? • We are out of IPv4 Space
• ARIN reports only 0.00374 of /8 left
– Only 245 /24s left (62,720 IPs left)
• Approximately 42.4% of the world’s population uses the internet as of Dec 2014, where as only 12.7% used the internet in Dec 2004. (internetworldstats.com)
Where are we at with IPv6 Deployment? • Since World IPv6 Launch day, on June 6th,
2012, many companies including Time Warner Cable and Comcast have committed to launching IPv6.
• Currently most companies are running both IPv4 and IPv6 at the same time.
• Comcast, Charter, Cox and Time Warner Cable
What are the challenges to IPv6 deployment? • End Device support (software and hardware)
– Windows 7 and 8+ Support IPv6
– Mac OS X v10.1 and later Support IPv6
• End Device (Wireless Routers)
– Check your vendor’s website to see if IPv6 is supported.
Where are we at with IPv6 Deployment? – cont. • Most cable companies are providing IPv6 to
customers
– Network Devices have already been configured
– Network Backbone already supports IPv6
– IPv6 Allocations have already been received and deployed
What are the challenges… – cont. • Modem Support
– Not all modems have firmware that support IPv6.
– Each cable company has a list of supported IPv6 enabled modems.
• Website Support
– Most websites are IPv4 only. Many bigger sites such as Google, Yahoo, Microsoft all support IPv6.
What are the challenges… - cont. • End User
– Training for Field Techs/CSR/Engineers
– Subscriber training
Is my computer IPv6 Ready?
• Here is how you can check:
– Go to www.ipv6-test.com or www.test-ipv6.com
– Go to ipv6test.google.com
IPConfig
• Run cmd
• Type ‘ipconfig /all’
– Displays all IP Addresses
• Type ‘ipconfig /release’ & ‘ipconfig /renew’
– If you need to refresh the IP with the DHCP Server do a /release & /renew
• Type ‘ipconfig /flushdns’
– If you are having problems reaching some websites, run a /flushdns
Tracert (Traceroute)
• Run cmd • Shows latency and hopcount • Each hop is a router interface • Maximum hops on tracert is 30 • Type ‘tracert -6 google.com’
– To see if you can reach google or any other domain name. • Type ‘tracert -6 <ipv6 address>’
– If you are unable to resolve any DNS, you can still traceroute using an IP Address
• Type ‘tracert -6 <ipv6 gateway>’ – If you are trying to reach your local router’s gateway ip
address • Type ‘tracert -6 <cpe gateway ip>’
– If you are trying to reach your CPE gateway IP Address on the CMTS.
Ping
• Run cmd
• Great test for packet loss
• Type ‘ping google.com’
– To see if you can reach google or any other domain name
• Type ‘ping -6 –t <ip or domain name>’
– To test for packet loss on the internet. –t will continuously ping until cntr-c is pressed.
• Type ‘ping -6 –n <count> <ip or domain name>
– To test for packet loss with a specific amount of packets.
• Type ‘ping -6 –l <size of packet> <ip/domain>
– To test for packet loss with a greater packet size.
NSLookup
• Run cmd
• Used to query DNS Server and perform DNS Lookups
• Can be used to determine if DNS server is down or not reachable
• Type ‘nslookup google.com’
– Performs a standard lookup
• Type ‘nslookup <ip address>’
– Performs a reverse dns lookup to find domain name
• Type ‘nslookup <ip/domain> <server ip>’
– Performs a lookup using a different server
Network-tools.com
• Go to www.network-tools.com
– Many different network tools
– Allows you to ping from outside cable network
– Can check DNS Records
– Can also check email spam blacklists
