Re: [Idr] I-D Action: draft-ietf-idr-large-community-01.txt

[Nick Hilliard <[e-mail]>]

Tom,

t.petch wrote:
> Here, I would go for 'MUST be an ASN' (or else the community should not
> be transitive:-)

Every 32 bit number is an ASN, so there's an argument to say that this
is a tautology.

I don't think it's either viable or necessary to narrow down the text to
specify that the global administrator field MUST be the ASN of the
operator who assigns the community to the prefix.

The reason for this is that if large communities are used for inter-as
signaling, operators should only act at the edge router when the global
administrator field matches the peer-as, and if they need to interpret
the community tag further inside the network, they should use a
translation layer to map the semantics to a locally significant
community (i.e. the same as what we do for rfc1997 communities).  For
intra-as signaling, it doesn't matter because it's local semantics only.
 Either way, there is no compelling reason that this should be a MUST
and good reasons (e.g. operator discretion) that it shouldn't.

Nick