Customer use topo PointA - S93_A ---- MPLS link ------S93_B -----PointB.
PontA and PointB bind using VPLS service, so packet from A to B have MPLS header at MPLS link.
Customer send PADI packets from pointA to pointB. At S93_A and S93_B configured mirror feature and at neigbor interface trying statistic analysis. statistic analysis show unexpected result:
statistic analysis at S93_A, mirror OUT direction of MPLS link.
statistic analysisdisplay packet without MPLS header
statistic analysis at S93_B, mirror BOTH direction of MPLS link.
statistic analysisdisplay packet with MPLS header and additional packet without MPLS header
statistic analysisat S93_B, mirror IN direction of MPLS link.
statistic analysis display packet only with MPLS header, as expected
S93 mirroring realization have following shortcoming:
mirroring at OUT direction of packets happens before packet encapsulate to MPLS frame, so that's why Case 1 and Case 2 display unexpected packets.
If we are need getstatistic analysis result for MPLS packets, we are need statistic analysisthem only at INBOUND direction at S93, If configure also OUT direction we will not get correct packets at observe interface.
That shortoming didn't influence to traffic forwarding so it is safe for services.