On Jun 10, 2010, at 12:21 PM, Erik Nordmark wrote:
On 06/10/10 12:06 PM, Jonathan Hui wrote:
On Jun 10, 2010, at 11:35 AM, Erik Nordmark wrote:
When IPv6-in-IPv6 tunneling is used, what is the destination IP
address in the outer header? Normally it would be the router that
would strip the outer header and RH4. Is that the case here as well?
Yes, that is what we intended.
So a packet sent by R1 that will be forwarded outside of the ROLL
network will have a outer IPv6 header whose destination is the BR?
That is where we started. Draft-01 does have a line or two about the
possibility of exempting the last entry in a RH4 from the strict
source route rule, thus allowing R1 to send a packet without an outer
IP header but this idea still needs to be fleshed out. It would
require the BR to strip the RH4 and update the IPv6 Payload Length
accordingly. Are there any implications with this idea?
It wasn't clear to me whether you are proposing IPv6-in-IPv6
tunneling
for packets that come in via a border router.
Not sure I'm clear on your use case, but the restrictions in the
draft
are intended to prohibit the case where an RH4 cross a RPL domain
boundary. A RH4 may be added and/or removed at a border router, but
it
shouldn't process/maintain an existing RH4 across a RPL domain
boundary.
Understood. My question is when the BR adds RH4, does it also
encapsulate in an outer header?
Yes, that is the case with draft-01.
Thus is the only case when there is RH4 without IPv6-in-IPv6 when
both the source *and* the destination is a router in the ROLL network?
Certainly the source must be within the ROLL network. Whether or not
the destination has to be depends on whether it is acceptable for the
border router to strip RH4 headers that have have a Segments Left = 0
after processing.
Thoughts?
--
Jonathan Hui
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