XR Embedded Packet Tracer

[Aleksandar Vidakovic]

Service flow verification and forwarding troubleshooting have just been made much easier with the introduction of the XR Embedded Packet Tracer framework.

The first platform on which this functionality is supported is the ASR9000, starting with release 7.1.2.

Watch a demo video and read more about the XR Embedded Packet Tracer at: https://xrdocs.io/asr9k/tutorials/xr-embedded-packet-tracer/

[tsiemers1]

Hey @Aleksandar Vidakovic  Do you by chance have any examples of using embedded packet trace to capture BNG Geo Redundancy Packets. I am struggling to figure out how to build the Offsets to capture pppoe sessions packets for a user.

PW-Ether6365.3065.pppoe75

Thanks,

Ty

[Aleksandar Vidakovic]

hi @tsiemers1 ,

if you're identifying the subscriber based on a MAC address, in that case the offset will depend on whether you are using the PW control word and/or FAT label. You will have to enable packet trace on physical interface where packets are received. 

[1] No PW control word, no FAT label

Protocol stack up to the encapsulated Ethernet header would be Ethernet+MPLS+Ethernet. Offset to the SMAC identifying the subscriber would be 24.

[2] PW control word, no FAT label

Protocol stack up to the encapsulated Ethernet header would be Ethernet+MPLS+PW_control+Ethernet. Offset to the SMAC identifying the subscriber would be 28.

[3] No PW control word, FAT label

Protocol stack up to the encapsulated Ethernet header would be Ethernet+MPLS+MPLS+Ethernet. Offset to the SMAC identifying the subscriber would be 28.

[4] PW control word, FAT label

Protocol stack up to the encapsulated Ethernet header would be Ethernet+MPLS+MPLS+PW_control+Ethernet. Offset to the SMAC identifying the subscriber would be 32.

For packet tracing based on the MAC address, you can use up to 4 consecutive octets in the offset/mask.

If you're matching on the first 4 octets of the SMAC 0000.aaaa.bbbb, the condition in scenario #1 above would be:
packet-trace condition 1 offset 28 value 0x0000aaaa mask 0xffffffff

If you're matching on the last 4 octets of the SMAC 0000.aaaa.bbbb, the condition in scenario #1 above would be:
packet-trace condition 1 offset 32 value 0xaaaabbbb mask 0xffffffff

Hope this helps,

/Aleksandar