Export of MPLS Segment Routing Label Type Information in
IP Flow Information Export (IPFIX)SwisscomBinzring 17Zurich8045Switzerlandthomas.graf@swisscom.comThis document introduces additional code points in the
mplsTopLabelType Information Element for IS-IS, OSPFv2, OSPFv3 MPLS
Segment Routing (SR) extensions and a new SID type element to enable
Segment Routing label and segment type information in IP Flow
Information Export (IPFIX).Besides BGP-4, LDP and BGP VPN,
three new routing-protocols, OSPFv2
Extensions, OSPFv3 Extensions and
IS-IS Extensions have been added to the
list of routing-protocols able to propagate Segment Routing labels for the MPLS
dataplane.Traffic
Accounting in Segment Routing Networks describes how IPFIX can be
leveraged to account traffic to MPLS Segment Routing label dimensions
within a Segment Routing domain.In the Information Model for IP Flow
Information Export IPFIX, the information element #46
mplsTopLabelType describes which MPLS control plane protocol allocated
the top-of-stack label in the MPLS label stack. RFC 7012 section 7.2 describes the IANA Information Element #46 SubRegistry
where new code points should be added.By introducing three new code points to information element #46
mplsTopLabelType for IS-IS, OSPFv2 and OSPFv3, when Segment Routing with
one of these three routing protocols is deployed, we get insight into
which traffic is being forwarded based on which MPLS control plane
protocol.A typical use case scenario is to monitor MPLS control plane
migrations from LDP to IS-IS or OSPF. By looking at the MPLS label value
itself, it is not always clear as to which label protocol it belongs,
since they could potentially share the same label allocation range. This
is the case for IGP-Adjacency SID's and LDP as an example.The introduction of a new Information Element called SrSidType, which
contains the Segment Routing Segment Identifier type according to Segment Routing Architecture, allows the Segment
Routing forwarding behaviour to be exported in IPFIX.A typical use case scenario is to monitor the forwarding behaviour
when Topology
Independent Fast Reroute or micro loop
avoidance tunnel traffic with IGP-Adjacency Segment SID's or when
ECMP load balancing should occur with Anycast-SID's.This document specifies three additional code points for IS-IS, OSPv2
and OSPFv3 Segment Routing extension in the existing sub-registry "IPFIX
MPLS label type (Value 46)" of the "IPFIX Information Elements" and one
new "IPFIX Information Element" with a new sub-registry in the "IP Flow
Information Export (IPFIX) Entities" name space.The same security considerations apply as for the IPFIX Protocol
RFC7012.I would like to thank Paul Aitken, Loa Andersson, Tianran Zhou,
Pierre Francois, Bruno Decreane and Paolo Lucente for their review and
valuable comments.IANA IP Flow Information Export (IPFIX) Information Element
#46 SubRegistry