[j-nsp] VPLS q-in-q

[Baldur Norddahl]

On 20.05.2020 15.04, Mark Tees wrote:
> Assuming 00:22:07:4d:7b:0d is the MAC behind the Juniper and the PCAP
> is on NIC of the host connected to the ZTE.
>
> At a guess the ZTE doing something different on ingress than what I am
> thinking here.
>
> If you can verify by PCAP on MPLS interface it would be handy to see
> what each side is doing in each direction. Juniper MX operations in
> this regards have usually been pretty explicit.
>

Not so easy to interpret but here is a capture of the MPLS packet sent 
by the ZTE device. The capture device (a Linux box with bridge) is 
sitting in between those the ZTE switch and the Juniper MX204. They 
would not usually be directly connected like this, but I am in the lab.

Frame 60: 368 bytes on wire (2944 bits), 368 bytes captured (2944 bits)
Ethernet II, Src: Zte_ba:ef:84 (0c:12:62:ba:ef:84), Dst: 
JuniperN_8f:dc:73 (e4:5d:37:8f:dc:73)
MultiProtocol Label Switching Header, Label: 238, Exp: 0, S: 1, TTL: 255
     0000 0000 0000 1110 1110 .... .... .... = MPLS Label: 238
     .... .... .... .... .... 000. .... .... = MPLS Experimental Bits: 0
     .... .... .... .... .... ...1 .... .... = MPLS Bottom Of Label Stack: 1
     .... .... .... .... .... .... 1111 1111 = MPLS TTL: 255
Data (350 bytes)
     Data: ffffffffffff0022074d7b0d810001a8810000c908004500...
     [Length: 350]

0000   ff ff ff ff ff ff 00 22 07 4d 7b 0d 81 00 01 a8 ÿÿÿÿÿÿ.".M{....¨
0010   81 00 00 c9 08 00 45 00 01 48 00 00 00 00 40 11 ...É..E..H.... at .
0020   79 a6 00 00 00 00 ff ff ff ff 00 44 00 43 01 34 y¦....ÿÿÿÿ.D.C.4
0030   be 52 01 01 06 00 79 b3 e8 65 2b 95 00 00 00 00 ¾R....y³èe+.....
0040   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 22 ..............."
0050   07 4d 7b 0d 00 00 00 00 00 00 00 00 00 00 00 00 .M{.............
0060   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0070   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0080   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0090   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00a0   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00b0   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00c0   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00d0   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00e0   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00f0   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0100   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0110   00 00 00 00 00 00 00 00 00 00 00 00 00 00 63 82 ..............c.
0120   53 63 35 01 01 39 02 02 40 37 0e 01 03 06 0c 0f Sc5..9.. at 7......
0130   1c 2a 2b 42 43 80 84 85 d4 3c 15 45 47 33 30 30 .*+BC...Ô<.EG300
0140   41 2d 57 55 32 31 55 41 43 2d 49 4e 54 45 4e 4f A-WU21UAC-INTENO
0150   0c 0b 49 6e 74 65 6e 6f 5f 37 42 30 41 ff ..Inteno_7B0Aÿ

I pasted that stuff into the packet decoder at https://hpd.gasmi.net/ 
and surprisingly found out that both outer and inner vlan is present. I 
thought it would not transmit the outer vlan. Still does not explain why 
I am having trouble then.

I need to go home now but I clearly need to investigate more.


Regards,

Baldur