Posted filed under Cisco CCNP.

Source Logical Operations

#### Configuring IPv6

• Overview of IPv6
• Implement IPv6 Addressing
• Implement IPv6 and IPv4
• Transition from IPv4 to IPv6

#### IPv6 Overview

• Solves the problem of shrinking IP address pools
• Solves many administrative inefficiencies cause by manual configuration

#### IPv6 Benefits

• Extended address space
• Hierarchical addressing and router efficiency
• Stateless and stateful address auto-configuration
• Integrated security (IPSec)
• Integrated QoS
• Eliminates need for NAT

#### IPv6 Address Space

• IPv4 address bit order, expressed as decimal and binary:
• IPv6 uses 128-bit addresses – 4 times the length of IPv4.
• Separated into eight 16-bit blocks:

#### IPv6 Address Space (Cont.)

Converting from binary to hexadecimal for IPv6:

• Take the first 16-bit block and break it into four groups of four bits as shown:
0010 0000 0000 0001
• Convert each bit in a group from right to left, with 0 converting to 0, and 1 converting to its position value:
2001
• Separate each converted block with a colon:
2001:0DB8:0000:2F3B:02AA:00FF:FE28:9C5A

#### The Hexadecimal Numbering System

• Base 16 numbering system
• 0 through 9, A through F
 Binary Decimal Hexadecimal 0001 1 1 0010 2 2 0011 3 3 0100 4 4 0101 5 5 0110 6 6 0111 7 7 1000 8 8 1001 9 9 1010 10 A 1011 11 B 1100 12 C 1101 13 D 1110 14 E 1111 15 F

#### Zero Compression

• Allows reduction of notation
• Adjacent zeros are compressed
• One or more blocks of zeros can be written as ::
• Only one set of :: in an address
• Single block of zeros can also be written as 0

Example:

2001:0DB8:0000:0000:02AA:00FF:FE28:9C5A

After dropping lead 0s and using zero compression:

2001:DB8::2AA:FF:FE28:9C5A

#### IPv6 Prefixes

• Network part of address
• Can be aggregated for route summarization
 Category Prefix Hex Value Prefix Binary Value Reserved – 0000 0000 Global unicast address 2 or 3 001 Link-local unicast addresses FE8 1111 1110 1000 Unique local unicast addresses FD 1111 1100 Multicast addresses FF 1111 1111

• Global unicast address
• Public, routable, from an ISP
• Automatically generated
• Non-routable
• Similar in function to IPv4 APIPA addresses
• Unique local unicast addresses
• Routable within an organization
• Not routable on the Internet
• Similar in function to IPv4 private addresses

#### Zone ID

• Relative to sending host
• Identifies the interface that is transmitting
• Syntax is address%zone_ID

#### IPv6 Address Auto-configuration

• Automatic for IPv6-enabled hosts
• Stateless
• Checks to see if link-local address is a duplicate
• Collects all valid prefixes advertised by adjacent routers
• Creates a global IPv6 address within each advertised /64 IPv6 prefix
• Uses either EUI-64 format or pseudo-random host ID as specified by RFC
• Stateful
• Obtained from DHCPv6
• Combination of stateless and stateful

#### Node Types

• IPv4 only
• IPv6 only
• IPv6/IPv4 – Uses both IPv4 and IPv6
• IPv4 – Uses IPv4; can be configured for IPv6
• IPv6 – Uses IPv6; can be configured for IPv4

#### IPv6 over IPv4

• Used in Windows 2008 and Windows 2012
• Also called “6over4”
• A transition mechanism
• Does translations from IPv4 to IPv6
• Uses multicast; both nodes and routers

#### Dual-Layer Architecture

• Microsoft has dual IP layer
• Not dual IP stack
• Both IPv4 and IPv6 share same information in same TCP/IP stack
• Single shared implementation of TCP and UDP

#### DNS Requirements

• Required for both IPv4
• and IPv6
• IPv4 Host record (A)
• IPv6 Host record (AAAA)
• PTR

#### Tunneling

• ISATAP
• The 6to4 protocol
• Teredo

#### ISATAP

• Transmits packets on top of IPv4
• Treats IPv4 infrastructure as a non-broadcast multi-access network
• IPv6 address auto-configuration
• Queries DNS for address of ISATAP router
• ISATAP router encapsulates IPv6 into IPv4 packets
• Not “NAT friendly”

#### The 6to4 Protocol

• Unicast connectivity between IPv6 across IPv4
• IPv6 encapsulated in IPv4
• Address format 2002:WWXX:YYZZ:Subnet_ID:Interface_ID
• Not “NAT friendly”

#### Teredo

• A NAT traversal technology
• Full IPv6 connectivity to IPv6 hosts that are on an IPv4 network
• Encapsulates IPv6 in IPv4 UDP messages
• Clients are assigned an IPv6 address that starts with (2001:0::/32)
• Teredo server initially configures Teredo tunnel
• Teredo relay – remote end de-encapsulates Teredo tunnel

#### PortProxy

• Transition mechanism
• Application gateway
• Proxies TCP traffic between IPv4 and IPv6 nodes
• Connection can be forwarded using the same or another protocol to the specified port number
• Allows you to run IPv4 only services (like terminal services) over IPv6
• The following nodes can access each other:
• An IPv4-only node can access an IPv4 node.
• An IPv4 node can access an IPv6 node.
• An IPv6 node can access an IPv6 node.
• An IPv6 node can access an IPv4 node.

#### Migration Considerations

• Application support
• Current routing infrastructure
• DNS infrastructure needs
• Supporting nodes
• Preparation and baselines
• Monitoring steps