Re: Updating to RFC6434 to deal with 8200-style header insertion by IPIP

[Brian E Carpenter <[e-mail]>]

On 12/11/2017 19:52, Fernando Gont wrote:
> Hi, Bob,
> 
> On 11/12/2017 10:50 AM, Bob Hinden wrote:
>> I went back and looked at the RFC8200 text that deals with header insertion.  It does not actually mention IPIP.  The published text in Section 4. "IPv6 Extension Headers" regarding header insertion is:
>>
>>    Extension headers (except for the Hop-by-Hop Options header) are not
>>    processed, inserted, or deleted by any node along a packet's delivery
>>    path, until the packet reaches the node (or each of the set of nodes,
>>    in the case of multicast) identified in the Destination Address field
>>    of the IPv6 header.
>>
>>    The Hop-by-Hop Options header is not inserted or deleted, but may be
>>    examined or processed by any node along a packet's delivery path,
>>    until the packet reaches the node (or each of the set of nodes, in
>>    the case of multicast) identified in the Destination Address field of
>>    the IPv6 header.  The Hop-by-Hop Options header, when present, must
>>    immediately follow the IPv6 header.  Its presence is indicated by the
>>    value zero in the Next Header field of the IPv6 header.
>>
>> Some earlier drafts include IPIP as a way of inserting headers, but that wasn’t included in what became RFC8200.
> 
> Does IPIP simply mean tunelling IP over IP?
> 
> If so, that'd be tunneling, rather than "header insertion".

Yes, but the point was to say that this is a valid way to attach extra
headers. And iirc we concluded that while true, it isn't necessary
to write it down.

(Also there's a proposed standard for this if you need it: RFC2473.)

   Brian