[bess] MPLS Label value 3 in <draft-dawra-bess-srv6-services-00>

Xiejingrong <xiejingrong@huawei.com> Thu, 27 June 2019 11:56 UTC

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From: Xiejingrong <xiejingrong@huawei.com>
To: "draft-dawra-bess-srv6-services@ietf.org" <draft-dawra-bess-srv6-services@ietf.org>, "bess@ietf.org" <bess@ietf.org>
Thread-Topic: MPLS Label value 3 in <draft-dawra-bess-srv6-services-00>
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Date: Thu, 27 Jun 2019 11:56:31 +0000
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Subject: [bess] MPLS Label value 3 in <draft-dawra-bess-srv6-services-00>
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Hi folks,

One question about MPLS Label value 3 used in <draft-dawra-bess-srv6-services-00>:

the Label value in any service route NLRI encoding MUST be set to Implicit NULL [RFC3032].

Label = Implicit NULL

I think the more common use of MPLS Label to represent "invalid" is to use zero, as in RFC7432 and RFC6556.

Why this document use value 3 (Implicit NULL as defined in RFC3032) ?