IPv6

Binary and Hex

Decimal counting goes to 10. Hexadecimal counts to 16. It uses the numbers 0-10 and then A,B,C,D,E,F. Computers use binary counting with bit 0 or 1 and 4-bit groups can be expressed in hexadecimal.

	BIN	DEC	HEX	Byte
	0000	0	0
	0001	1	1
	0010	2	2
	0011	3	4
	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	nible
	0001_0000	16	10
	0001_0001	17	11
	0111_1111	127	7F
	1000_0000	128	80
	1111_1111	255	FF	byte
	1_0000_0000	512	100
	10_0000_0000	1024	1000	kilo byte

Two characters together is a byte 1000 0000 is 0x80 and 1111 1111 is 0xFF is 255

IPv6 Addresses

IPv6 Addresses are 128 bits long, written down in 8 times 2 bytes long separated by a colon, 2 colons to shorten a long row of zero's ::1 means loopback address, so "own interface"

Mask

How many bits belong to the network. It is used for routing

FE80::/10 is used for local communication.

FF01::/16 is used for Multicast addresses, where the network gets to decide which service is closest.

2001::/16 is used for Global Unicast Addresses.

The mask /16 defines how many bits are used for the network part. The rest is the host part, routing works on the network part

Each interface has one or more addresses. The link will have a default fe80 address which is not routable outside the link scope

fe80::7c0e:e6ff:fe7b:40f0/64
fe80 is link-local address
ff:fe (plus the first 'bit') makes eui-48 mac an eui-64
rfc8064 replace the address with a hash

The gateway gets an IP address from the provider. Global address starts with 2001, the provider is abcd, the subnet is efg0, the

2001:db8:efg0:1234::1/128
/16 2001 is for unicast addresses
/48 0db8 is for the providers, db8 specifically is for documentation
/56 efg0 is for the subnet-id
/64 bits for end users to subdivide

Scope

%5

clients

Google Android does not support DHCPv6. It must use SLAAC for assigning IPv6 addresses. SLAAC must use /64 prefixes with EUI-64 host addresses.

OPNSense - WAN IPv6 DHCP Client: Request Prefix-only - LAN IPv6 track WAN, Prefix-ID 0x0

IPv6 Prefix ID

Manual configuration V

DUID

https://askubuntu.com/questions/1198955/how-can-i-change-my-ubuntus-ipv6-duid

https://man7.org/linux/man-pages/man5/machine-id.5.html

DHCPv6 Configured

a000 - ::f000

/usr/local/sbin/radvd -p /var/run/radvd.pid -C /var/etc/radvd.conf -m syslog

/var/etc/rarvd.conf

       foreach ($stanzas as $stanza) {
           $radvdconf .= "#\tprefix {$stanza} {\n";
           $stanza = strtok($stanza, '/');
           $stanza = $stanza."/64";
           $radvdconf .= "\tprefix {$stanza} {\n";

Stanza should have included Prefix-ID to make it /64

https://github.com/opnsense/docs/blob/master/source/manual/ipv6.rst

https://github.com/opnsense/docs/blob/master/source/manual/radvd.rst

src/etc/inc/plugins.inc.d/dhcpd.inc

list (, $networkv6) = interfaces_primary_address6($dhcpv6if, $ifconfig_details); if (is_subnetv6($networkv6)) {

   $stanzas[] = $networkv6;

} $stanzas[] = "{$subnetv6}/{$vip['subnet_bits']}";

https://github.com/opnsense/core/blob/master/src/etc/inc/plugins.inc.d/dhcpd.inc#L353

Add If statement to replace prefix to /64

IPv6

assign IP address

Setup routes

DNS servers

DHCPv6

SLAAC

M Managed Flag, advertise dhcpv6 exists

O Other Flag, use DHCP to assign other parameters

A Autonomous, use SLAAC Prefix to use EUI-64 and Privacy address

Prefix must be /64