Elwyn Davies wrote:
Some comments:
<<snip>>
s6.4.1: [wish list] It occurs to me with the mention of tunnels that a
Qtype to find out about the addresses associated with (e.g.)
configured tunnels would be useful (v6 in v4 for example).
Brian asked me to propose some text for this. Here is my suggestion -
adds an 'E' flag to the two Node Address queries ('E' stands for
Encapsulated). These two additions would allow a querier to find out
what 'inner' tunnel addresses were in use on a node - these are the
tunnel interface addresses of the node which are in addition to the
direct interfaces.
The updated text (scetins 6.3/6.4/6.4.1 is:
6.3. Node Addresses
The NI Node Addresses Query requests some set of the Responder's IPv6
unicast addresses. The Reply Data is a sequence of 128-bit IPv6
addresses, each address preceded by a separate 32-bit TTL value, with
Preferred addresses listed before Deprecated addresses [9], but
otherwise in no special order. Six flag bits are defined in the
Query, and seven in the Reply.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Qtype=3 | unused |E|G|S|L|C|A|T|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Node Information Address Query
o G - If set to 1, Global-scope addresses [10] are requested.
o S - If set to 1, Site-local addresses [10] are requested.
However, Site-local addresses are now deprecated [14] and this
flag is for backwards compatibility.
Crawford & Haberman Expires February 20, 2006 [Page 9]
Internet-Draft ICMP Name Lookups August 2005
o L - If set to 1, Link-local addresses [10] are requested.
o C - If set to 1, IPv4-compatible and IPv4-mapped addresses [3] are
requested. As the IPv4-compatible addresses are now deprecated,
this flag is for backwards compatibility with older
implementations,
o A - If set to 1, all the Responder's unicast addresses (of the
specified scope(s)) are requested. If 0, only those addresses are
requested which belong to the interface (or any one interface)
which has the Subject Address, or which are associated with the
Subject Name.
o T Defined in a Reply only, indicates that the set of addresses is
incomplete for space reasons.
o E - If set to 1, tunnel end-point addresses are requested. This
requests the 'inner' addresses of tunnels (v6 in v6 and/or v6 in v4,
depending on the type of the Subject field) terminating on the node.
This is treated as a 'scope' for the purposes of the 'A' flag. If
the subject is a Name then all IPv6 tunnel addresses are returned;
otherwise only addresses for tunnels with the same type of 'outer'
address as the Subject.
Flags G, S, L, C, A and E are copied from a Query to the corresponding
Reply.
The TTL associated with each address MUST be zero.
6.4. IPv4 Addresses
The NI IPv4 Addresses Query requests some set of the Responder's IPv4
unicast addresses. The Reply Data is a sequence of 32-bit IPv4
addresses, each address preceded by a 32-bit TTL value. Two flag bits
are defined in the Query, and three in the Reply.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Qtype=4 | unused |E|A|T|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Node Information IPv4 Address Query
o A - If set to 1, all the Responder's unicast addresses are
requested. If 0, only those addresses are requested which belong
to the interface (or any one interface) which has the Subject
Address.
o T Defined in a Reply only, indicates that the set of addresses is
incomplete for space reasons.
o E - If set to 1, tunnel end-point addresses are requested. This
requests the 'inner' addresses of tunnels (v4 in v4 and/or v4 in v6,
depending on the type of the Subject) terminating on the node. Only
tunnel end-point addresses are returned if this flag is set. If
the subject is a Name then all IPv4 tunnel addresses are returned;
otherwise only addresses for tunnels with the same type of 'outer'
address as the Subject.
Flags A and E are copied from a Query to the corresponding Reply.
The TTL associated with each address MUST be zero.
6.4.1. Discussion
It is possible that a node may treat IPv4 interfaces and IPv6
interfaces as distinct, even though they are associated with the same
hardware. When such a node is responding to an NI Query having a
Subject Address of one type requesting the other type, and the Query
has the A flag set to 0, it SHOULD consider IP interfaces, other than
tunnels, associated with the same hardware as being the same
interface. If tunnel addresses are requested, the addresses returned
SHOULD be the 'inner' addresses of any tunnels terminating on the same
Hardware.
Regards,
Elwyn
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