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--- networking:ipv6 [2022/11/19 08:30] – oscar
+++ networking:ipv6 [2022/11/19 10:35] (current) – [Default Route] oscar
@@ Line 1: / Line 1: @@
 ====== IPv6 ======
 ===== IPv6 Notation =====
-IPv6 addresses are 128 bits long (32 hexadecimal numbers) and consist of eight colon-delimited sections. Each section contains 2 bytes, and each byte is expressed as a hexadecimal number from 0 through FF. An IPv6 address looks like this:
+IPv6 addresses are 128 bits long (32 hexadecimal numbers) and consist of eight colon-delimited sections. Each section contains 2 bytes, and each byte is expressed as a hexadecimal number from 0 through FF. An IPv6 address looks like this: **2001:0db8:0000:0000:0000:0800:200c:7334**. By omitting the leading zeroes from each section or substituting contiguous sections that contain zeroes with a double colon, you can write the example address as:**2001:db8::800:200c:7334**.
-:0db8:0000:0000:0000:0800:200c:7334
+===== Subnetting =====
+An IPv6 address can be broken into a network address space and the nodes address space. The prefix length is a decimal value that specifies the **number of the leftmost bits** in the address that make up the prefix. The prefix length follows a forward slash and, identifies the portion of the address owned by an organization. All remaining bits (up to the right-most bit) represent individual nodes or interfaces.
+For example, **2001:db8:0000:0000:250:af:34ff:fe26/64** has a prefix length of **64**. The first 64 bits of this address (**2001:db8:0000:0000**) are the prefix. The rest (**250:af:34ff:fe26**) identify the interface.
-By omitting the leading zeroes from each section or substituting contiguous sections that contain zeroes with a double colon, you can write the example address as:
+IETF defined /64 to be the standard IPv6 subnet size. It is smallest subnet that can used locally if auto configuration is desired. Typically, an ISP assigns a /64 or smaller subnet to establish service on the WAN. An additional network is routed for LAN use.
-:db8:0:0:0:800:200c:7334 --> 2001:db8::800:200c:7334
+^bits (MSB) ^Purpose^
+|First 48 bits:|Network address|
+|Next 16 bits:|Subnet address|
+|Last 64 bits:|Device address|
-===== IPv6 Prefix =====
+===== Prefix =====
-An IPv6 address can be broken into a network address space and the nodes address space. The prefix length is a decimal value that specifies the **number of the leftmost bits** in the address that make up the prefix. The prefix length follows a forward slash and, identifies the portion of the address owned by an organization. All remaining bits (up to the right-most bit) represent individual nodes or interfaces.
+The default IPV6 prefix is 64-bit and consists on the network an subnet parts.
-For example, 2001:db8:0000:0000:250:af:34ff:fe26/64 has a prefix length of 64.
+**//Network+Subnet = Prefix//**
-The first 64 bits of this address (2001:db8:0000:0000) are the prefix. The rest (250:af:34ff:fe26) identify the interface.
+The following address **2003:1000:1000:1600:1234::1** would have the network **2003:1000:1000**, the subnet **1600**, so together the prefix **2003:1000:1000:1600**. If the ISP provider delegated a part of the prefix to me (e.g. 2003:1000:1000:1600/56) then I could use the subnets from 2003:1000:1000:1600 to 2003:1000:1000:16FF for my own purposes (i.e. define 256 subnets in this example)
+Ziggo provides a Prefix Delegated of 56-bits: **2001:1c00:2e16:7200::/56**.This means that Ziggo provides you /56 IPv6 address range. This allows you to create 256 subnets each being /64 large.
+===== Scopes =====
+  * GLOBAL - everything (i.e. the whole internet)
+  * UNIQUE LOCAL - everything in our LAN (behind the internet gateway)
+  * LINK LOCAL - (will never be routed, valid in one collision domain, i.e. on the same switch)
+^range^Purpose^
+|::1/128 |Loopback address (localhost)|
+|::/128 |unspecified address|
+|2000::/3 |GLOBAL unicast (Internet)|
+|fc00::/7  |Unique-local (LAN)|
+|fe80::/10 |Link-Local Unicast (same switch)|
+Always use the smallest possible scope for communication
+A host can have multiple addresses in different scopes
 ===== IPv6 Address Types =====
 ==== Unicast ====
@@ Line 53: / Line 74: @@
   - DHCPv6 - Dynamic host configuration protocol (assigned by central server)
-===== Network Discovery =====
+{{ :networking:slaac-dhcpv6.png?400 |}}
+==== SLAAC ====
+Stateless Auto Address Configuration (SLAAC) enables hosts to create their own unique IPv6 global unicast address without the services of a DHCPv6 server that maintains network address information to know which IPv6 addresses are being used and which ones are available.
+  * SLAAC router sends periodic ICMPv6 RA **Router Advertisement** messages (i.e., every 200 seconds) providing addressing and other configuration information for hosts to auto configure their IPv6 address based on the information in the RA.
+  * SLAAC host configures it address using the **Router Advertisement** (RA) messages send by the router
+  * A host can also send a **Router Solicitation** (RS) message requesting an RA.
+  * SLAAC can be deployed as SLAAC only, or SLAAC with DHCPv6
+==== DHCPv6 ====
+Stateful DHCPv6 does not require SLAAC while stateless DHCPv6 does. Regardless, when an RA indicates to use DHCPv6 or stateful DHCPv6:
+  - The host sends an RS message.
+  - The router responds with an RA message.
+  - The host sends a DHCPv6 SOLICIT message.
+  - The DHCPv6 server responds with an ADVERTISE message.
+  - The host responds to the DHCPv6 server.
+  - The DHCPv6 server sends a REPLY message.
+=== Stateless DHCPv6 Operation ===
+If an RA indicates the stateless DHCPv6 method:
+  * the host uses the information in the RA message for addressing and contacts a DHCPv6 server for additional information.
+  * Note: The DHCPv6 server only provides configuration parameters for clients and does not maintain a list of IPv6 address bindings (i.e. stateless).
+=== Statefull DHCPv6 Operation ===
+If an RA indicates the statefull DHCPv6 method:
+  * the host contacts a DHCPv6 server for all configuration information.
+  * Note: The DHCPv6 server is statefull and maintains a list of IPv6 address bindings
+===== Troubleshooting =====
+==== Show address ====
+  ip -6 address show
+==== Default Route ====
+  ip -6 route show | grep default
+==== Ping the host ====
+ping6 fe80::ee08:6bff:fe84:2043
+==== Network Discovery ====
 <code>
 ip -6 neigh show
@@ Line 75: / Line 128: @@
 ping6 -c3 -n -I <your network interface fda1 ip> ff02::1     --> lists all local network addresses
 </code>
+===== IPv6 addresses in URIs/URLs =====
+Because IPv6 address notation uses colons to separate hextets, it is necessary to encase the address in square brackets in URIs. For example http://[2a00:1450:4001:82a::2004]. If you want to specify a port, you can do so as normal using a colon: http://[2a00:1450:4001:82a::2004]:80.