Use label field in EVPN routes as 24-bit value when encapsulation is VXLAN

[Nischal Sheth]

When EVPN routes are advertised with VXLAN encapsulation, the ethernet
tag field is set to the VNI value. Further, the label is also set to
the VNI value by Contrail and JUNOS.

Reading of https://tools.ietf.org/html/draft-ietf-bess-evpn-overlay-01
was that the VNI would be encoded as a 20-bit label value consistent
with how MPLS labels are encoded. However, it turns out that we need
to use the entire 24 bits as the label when the encapsulation is VXLAN.
Note that the bottom 4 bits of the label field in the EVPN route are ignored when we use it to carry an MPLS label.

JUNOS currently treats the label as a 20-bit value but will change to
using it as a 24-bit value before the EVPN + VXLAN code is released.
This is required to interoperate with other vendors.

Since the VNI value is already carried in the ethernet tag field we can
make the change from 20-bit to 24-bit labels in a backward compatible
manner with JUNOS as follows. When the encapsulation is VXLAN, if the
ethernet tag is non-zero use that as the label value, else honor the
label. JUNOS already has this logic in place.

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11570
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11571
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11574
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11575
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11570
Committed: http://github.org/Juniper/contrail-controller/commit/b9d636a2ca44a6cb0d428e8c4eb9c2bd1a988c36
Submitter: Zuul
Branch: master

commit b9d636a2ca44a6cb0d428e8c4eb9c2bd1a988c36
Author: Nischal Sheth <email address hidden>
Date: Thu Jun 11 17:27:15 2015 -0700

Use label as 24-bit field when encoding/decoding VNI

Change-Id: I60cdae79cf4a8b60ebb9ed271ccafca4193d4a91
Closes-Bug: 1464781

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11571
Committed: http://github.org/Juniper/contrail-controller/commit/5cf95b2169e479492eb866a89f60544bc9d06eb0
Submitter: Zuul
Branch: R2.20

commit 5cf95b2169e479492eb866a89f60544bc9d06eb0
Author: Nischal Sheth <email address hidden>
Date: Thu Jun 11 17:27:15 2015 -0700

Use label as 24-bit field when encoding/decoding VNI

Change-Id: I60cdae79cf4a8b60ebb9ed271ccafca4193d4a91
Closes-Bug: 1464781

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11574
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11575
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11574
Committed: http://github.org/Juniper/contrail-controller/commit/018cc751cabc513a930ee52dc631023232312d3e
Submitter: Zuul
Branch: R2.0

commit 018cc751cabc513a930ee52dc631023232312d3e
Author: Nischal Sheth <email address hidden>
Date: Thu Jun 11 17:27:15 2015 -0700

Use ethernet tag as label if encapsulation is VXLAN

Note that we still encode/decode the label as a 20-bit value
in this release.

This provides backward compatibility with older 2.0 releases
and forward compatibility with 2.20 and newer releases. Note
that all releases set the VNI as the ethernet tag.

Change-Id: I60cdae79cf4a8b60ebb9ed271ccafca4193d4a91
Closes-Bug: 1464781

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11575
Committed: http://github.org/Juniper/contrail-controller/commit/54a798d218b735b09df205a3a7fb5630a33debea
Submitter: Zuul
Branch: R2.1

commit 54a798d218b735b09df205a3a7fb5630a33debea
Author: Nischal Sheth <email address hidden>
Date: Thu Jun 11 17:27:15 2015 -0700

Use ethernet tag as label if encapsulation is VXLAN

Note that we still encode/decode the label as a 20-bit value
in this release.

This provides backward compatibility with older 2.0 releases
and forward compatibility with 2.20 and newer releases. Note
that all releases set the VNI as the ethernet tag.

Change-Id: I60cdae79cf4a8b60ebb9ed271ccafca4193d4a91
Closes-Bug: 1464781

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11916
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11917
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11916
Committed: http://github.org/Juniper/contrail-controller/commit/4e0792cfb6d382ce4c5f753c22e1fd8cd72a343b
Submitter: Zuul
Branch: R2.20

commit 4e0792cfb6d382ce4c5f753c22e1fd8cd72a343b
Author: Nischal Sheth <email address hidden>
Date: Mon Jun 22 00:38:14 2015 -0700

Use 24-bit label when encoding/decoding VNI in PmsiTunnel

Change-Id: I3f2abe0922ea69742a325765a5df95899149798f
Closes-Bug: 1464781

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11917
Committed: http://github.org/Juniper/contrail-controller/commit/d875d7da7eee8432a3e399491ceaed74107a2a74
Submitter: Zuul
Branch: master

commit d875d7da7eee8432a3e399491ceaed74107a2a74
Author: Nischal Sheth <email address hidden>
Date: Mon Jun 22 00:38:14 2015 -0700

Use 24-bit label when encoding/decoding VNI in PmsiTunnel

Change-Id: I3f2abe0922ea69742a325765a5df95899149798f
Closes-Bug: 1464781

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11943
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/11944
Submitter: Nischal Sheth (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11943
Committed: http://github.org/Juniper/contrail-controller/commit/289c50d60ef3197ed8ef17f48423cabbce1f66c0
Submitter: Zuul
Branch: R2.0

commit 289c50d60ef3197ed8ef17f48423cabbce1f66c0
Author: Nischal Sheth <email address hidden>
Date: Mon Jun 22 12:39:35 2015 -0700

Use ethernet tag as label for PmsiTunnel if encap is VXLAN

Note that we still encode/decode the label as a 20-bit value
in this release.

This provides backward compatibility with older 2.0 releases
and forward compatibility with 2.20 and newer releases. Note
that all releases set the VNI as the ethernet tag.

Change-Id: If5d2d0a2bbfc7dc1634652de07d4bfec271deeac
Closes-Bug: 1464781

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/11944
Committed: http://github.org/Juniper/contrail-controller/commit/dc7ac032bc7c727172d41cad82a1a496bee8ec0d
Submitter: Zuul
Branch: R2.1

commit dc7ac032bc7c727172d41cad82a1a496bee8ec0d
Author: Nischal Sheth <email address hidden>
Date: Mon Jun 22 12:39:35 2015 -0700

Use ethernet tag as label for PmsiTunnel if encap is VXLAN

Note that we still encode/decode the label as a 20-bit value
in this release.

This provides backward compatibility with older 2.0 releases
and forward compatibility with 2.20 and newer releases. Note
that all releases set the VNI as the ethernet tag.

Change-Id: If5d2d0a2bbfc7dc1634652de07d4bfec271deeac
Closes-Bug: 1464781