cnp3-ebook/protocols/ipv6 — English @ Weblate

Exit Zen

66 ../../protocols/ipv6.rst:225

	English The longest prefix match can be implemented by using different data structures One possibility is to use a trie. Details on how to implement efficient packet forwarding algorithms may be found in [Varghese2005]_. 212/10000 · 212
67 ../../protocols/ipv6.rst:230

	English For the companies that want to use IPv6 without being connected to the IPv6 Internet, :rfc:`4193` defines the `Unique Local Unicast (ULA)` addresses (``fc00::/7``). These ULA addresses play a similar role as the private IPv4 addresses defined in :rfc:`1918`. However, the size of the ``fc00::/7`` address block allows ULA to be much more flexible than private IPv4 addresses. 375/10000 · 375
68 ../../protocols/ipv6.rst:234

	English Furthermore, the IETF has reserved some IPv6 addresses for a special usage. The two most important ones are : 109/10000 · 109
69 ../../protocols/ipv6.rst:236

	English ``0:0:0:0:0:0:0:1`` (``::1`` in compact form) is the IPv6 loopback address. This is the address of a logical interface that is always up and running on IPv6 enabled hosts. 171/10000 · 171
70 ../../protocols/ipv6.rst:237

	English ``0:0:0:0:0:0:0:0`` (``::`` in compact form) is the unspecified IPv6 address. This is the IPv6 address that a host can use as source address when trying to acquire an official address. 184/10000 · 184
71 ../../protocols/ipv6.rst:241

	English The last type of unicast IPv6 addresses are the `Link Local Unicast` addresses. These addresses are part of the `fe80::/10` address block and are defined in :rfc:`4291`. Each host can compute its own link local address by concatenating the `fe80::/64` prefix with the 64 bits identifier of its interface. Link local addresses can be used when hosts that are attached to the same link (or local area network) need to exchange packets. They are used notably for address discovery and auto-configuration purposes. Their usage is restricted to each link and a router cannot forward a packet whose source or destination address is a link local address. Link local addresses have also been defined for IPv4 :rfc:`3927`. However, the IPv4 link local addresses are only used when a host cannot obtain a regular IPv4 address, e.g. on an isolated LAN. 841/10000 · 841
72 ../../protocols/ipv6.rst:259

	English All IPv6 hosts have several addresses 37/10000 · 37
73 ../../protocols/ipv6.rst:261

	English An important consequence of the IPv6 unicast addressing architecture and the utilization of link-local addresses is that each IPv6 host has several IPv6 addresses. This implies that all IPv6 stacks must be able to handle multiple IPv6 addresses. 245/10000 · 245
74 ../../protocols/ipv6.rst:265

	English The addresses described above are unicast addresses. These addresses are used to identify (interfaces on) hosts and routers. They can appear as source and destination addresses in the IPv6 packets. When a host sends a packet towards a unicast address, this packet is delivered by the network to its final destination. There are situations, such as when delivering video or television signal to a large number of receivers, where it is useful to have a network that can efficiently deliver the same packet to a large number of receivers. This is the `multicast` service. A multicast service can be provided in a LAN. In this case, a multicast address identifies a set of receivers and each frame sent towards this address is delivered to all receivers in the group. Multicast can also be used in a network containing routers and hosts. In this case, a multicast address identifies also a group of receivers and the network delivers efficiently each multicast packet to all members of the group. Consider for example the network below. 1033/10000 · 1033
75 ../../protocols/ipv6.rst:289

	English Assume that ``B`` and ``D`` are part of a multicast group. If ``A`` sends a multicast packet towards this group, then ``R1`` will replicate the packet to forward it to ``R2`` and ``R3``. ``R2`` would forward the packet towards ``B``. ``R3`` would forward the packet towards ``R4`` that would deliver it to ``D``. 312/10000 · 312
76 ../../protocols/ipv6.rst:291

	English Finally, :rfc:`4291` defines the structure of the IPv6 multicast addresses [#fmultiiana]_. This structure is depicted in the figure below. 138/10000 · 138
77 ../../protocols/ipv6.rst:314

	English The low order 112 bits of an IPv6 multicast address are the group's identifier. The high order bits are used as a marker to distinguish multicast addresses from unicast addresses. Notably, the 4-bit `Flags` field indicates whether the address is temporary or permanent. Finally, the `Scope` field indicates the boundaries of the forwarding of packets destined to a particular address. A link-local scope indicates that a router should not forward a packet destined to such a multicast address. An organization local-scope indicates that a packet sent to such a multicast destination address should not leave the organization. Finally the global scope is intended for multicast groups spanning the global Internet. 713/10000 · 713
78 ../../protocols/ipv6.rst:316

	English Among these addresses, some are well known. For example, all hosts automatically belong to the ``ff02::1`` multicast group while all routers automatically belong to the ``ff02::2`` multicast group. A detailed discussion of IPv6 multicast is outside the scope of this chapter. 275/10000 · 275
79 ../../protocols/ipv6.rst:321

	English IPv6 packet format 18/10000 · 18
80 ../../protocols/ipv6.rst:323

	English The IPv6 packet format was heavily inspired by the packet format proposed for the SIPP protocol in :rfc:`1710`. The standard IPv6 header defined in :rfc:`2460` occupies 40 bytes and contains 8 different fields, as shown in the figure below. 240/10000 · 240
81 ../../protocols/ipv6.rst:329

	English The IP version 6 header (:rfc:`2460`) 37/10000 · 37
82 ../../protocols/ipv6.rst:331

	English Apart from the source and destination addresses, the IPv6 header contains the following fields : 96/10000 · 96
83 ../../protocols/ipv6.rst:333

	English `Version` : a 4 bits field set to `6` and intended to allow IP to evolve in the future if needed 96/10000 · 96
84 ../../protocols/ipv6.rst:334

	English `Traffic class` : this 8 bits field indicates the type of service expected by this packet and contains the ``CE`` and ``ECT`` flags that are used by `Explicit Congestion Notification` 183/10000 · 183
85 ../../protocols/ipv6.rst:335

	English `Flow Label` : this field was initially intended to be used to tag packets belonging to the same `flow`. A recent document, :rfc:`6437` describes some possible usages of this field, but it is too early to tell whether it will be really used. 241/10000 · 241

Shortcut	Action
`?`	Open available keyboard shortcuts.
`Alt` + `Home`	Navigate to the first translation in the current search.
`Alt` + `End`	Navigate to the last translation in the current search.
`Alt` + `PageUp` or `Ctrl` + `↑` or `Alt` + `↑` or `Cmd` + `↑` or	Navigate to the previous translation in the current search.
`Alt` + `PageDown` or `Ctrl` + `↓` or `Alt` + `↓` or `Cmd` + `↓` or	Navigate to the next translation in the current search.
`Ctrl` + `Enter` or `Cmd` + `Enter`	Submit current form; this works the same as pressing Save and continue while editing translation.
`Ctrl` + `Shift` + `Enter` or `Cmd` + `Shift` +`Enter`	Unmark translation as Needing edit and submit it.
`Alt` + `Enter` or `Option` + `Enter`	Submit the string as a suggestion; this works the same as pressing Suggest while editing translation.
`Ctrl` + `E` or `Cmd` + `E`	Focus on translation editor.
`Ctrl` + `U` or `Cmd` + `U`	Focus on comment editor.
`Ctrl` + `M` or `Cmd` + `M`	Shows Automatic suggestions tab.
`Ctrl` + `1` to `Ctrl` + `9` or `Cmd` + `1` to `Cmd` + `9`	Copies placeable of a given number from source string.
`Ctrl` + `M` followed by `1` to `9` or `Cmd` + `M` followed by `1` to `9`	Copy the machine translation of a given number to current translation.
`Ctrl` + `I` followed by `1` to `9` or `Cmd` + `I` followed by `1` to `9`	Ignore one item in the list of failing checks.
`Ctrl` + `J` or `Cmd` + `J`	Shows the Nearby strings tab.
`Ctrl` + `S` or `Cmd` + `S`	Focus on search field.
`Ctrl` + `O` or `Cmd` + `O`	Copy the source string.
`Ctrl` + `Y` or `Cmd` + `Y`	Toggle the Needs editing checkbox.
`→`	Browse the next translation string.
`←`	Browse the previous translation string.