Re: Is TS agreement necessary?

[Joe Touch <touch@ISI.EDU>]

Lars Eggert wrote:
> Stephen Kent wrote:
> 
>> RFC 2401 is reasonably clear in noting that the SPD is nominally per 
>> interface. What sort of management interface is provided to a client 
>> is up to the vendor, so long as one can achieve the same effects as a 
>> per-interface SPD.  Otherwise, the implementation would not be compliant
> 
> As a side note, I misunderstood this for a long time to mean "SPD per 
> PHYSICAL interface", which is not sufficient (because of ambiguities via 
> multiple matching tunnel-mode SAs in the same per-physical-interface 
> SPD). When viewing tunnel mode SAs as virtual interfaces in their own 
> right that have separate SPDs associated with them, these problems 
> dissapear. Maybe that's part of the confusion around tunnel mode...
> Lars

Hi, Steve,

One of the confusions I have is regarding systems that say they use 
these tunnel mode SAs as virtual interfaces. It seems that the tunnel SA 
has to be in the SPD of the underlying interface, but they only work if 
the SA is in the SPD of the virtual interface (i.e., inside the tunnel). 
That seems self-referential... ??

Joe