2014-03-15

Capture your fancy, part two, Trio

Like with 7600/PFC3, it is possible to capture transit traffic on Juniper Trio (MPC, MX80, MX104, FPC5 etc). First decide what you know about the packet and convert that data to hex, it can be pretty much anywhere in the packet in the first 320B or so.

[ytti@ytti.fi ~]% pry [1] pry(main)> '194.100.7.227'.split('.').map{|e|"%02x" % [e.to_i]}.join => "c26407e3" [2] pry(main)> '91.198.120.24'.split('.').map{|e|"%02x" % [e.to_i]}.join => "5bc67818"

I'm using boringly IPv4 addresses but I could have used anything. Unlike in PFC3 you do not need tell the location in the packet where the pattern must occur, you just tell pattern and any packet having that pattern anywhere is triggered, let's try it:

fisakytt@mec-pe1-re0.hel.fi> start shell pfe network tfeb0 TFEB platform (1000Mhz MPC 8544 processor, 1024MB memory, 512KB flash) TAZ-TBB-0(mec-pe1-re0.hel.fi vty)# test jnh 0 packet-via-dmem enable TAZ-TBB-0(mec-pe1-re0.hel.fi vty)# test jnh 0 packet-via-dmem capture 0x3 5bc67818c26407e3 TAZ-TBB-0(mec-pe1-re0.hel.fi vty)# test jnh 0 packet-via-dmem dump Received 116 byte parcel: Dispatch cookie: 0x0074000000000000 0x00 0x08 0x80 0xf0 0x80 0x08 0x5c 0x5e 0xab 0x0b 0x6e 0x60 0xb0 0xa8 0x6e 0x7c 0x60 0x52 0x88 0x47 0x00 0x00 0x01 0xfe 0x45 0x00 0x00 0x54 0x81 0xaa 0x40 0x00 0x3f 0x01 0x1b 0xd9 0x5b 0xc6 0x78 0x18 0xc2 0x64 0x07 0xe3 0x08 0x00 0x8b 0xb8 0x0e 0xa4 0xed 0xdb 0xb6 0x0b 0x24 0x53 0x00 0x00 0x00 0x00 0xca 0x95 0x0c 0x00 0x00 0x00 0x00 0x00 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1a 0x1b 0x1c 0x1d 0x1e 0x1f 0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2a 0x2b 0x2c 0x2d 0x2e 0x2f 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37 Sent 111 byte parcel: 0x08 0xbf 0xe0 0x11 0x71 0x00 0x00 0x60 0x80 0x0e 0x80 0x18 0x9e 0x52 0x54 0x00 0x5c 0x97 0x46 0x5c 0x5e 0xab 0x0b 0x6e 0x7e 0x08 0x00 0x45 0x00 0x00 0x54 0x81 0xaa 0x40 0x00 0x3e 0x01 0x1c 0xd9 0x5b 0xc6 0x78 0x18 0xc2 0x64 0x07 0xe3 0x08 0x00 0x8b 0xb8 0x0e 0xa4 0xed 0xdb 0xb6 0x0b 0x24 0x53 0x00 0x00 0x00 0x00 0xca 0x95 0x0c 0x00 0x00 0x00 0x00 0x00 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1a 0x1b 0x1c 0x1d 0x1e 0x1f 0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2a 0x2b 0x2c 0x2d 0x2e 0x2f 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37 <...> Received 116 byte parcel: Dispatch cookie: 0x0074000000000000 0x00 0x09 0x00 0xf0 0x80 0x08 0x5c 0x5e 0xab 0x0b 0x6e 0x60 0xb0 0xa8 0x6e 0x7c 0x60 0x52 0x88 0x47 0x00 0x00 0x01 0xfe 0x45 0x00 0x00 0x54 0x81 0xcb 0x40 0x00 0x3f 0x01 0x1b 0xb8 0x5b 0xc6 0x78 0x18 0xc2 0x64 0x07 0xe3 0x08 0x00 0x47 0xbf 0x0e 0xa4 0xed 0xfc 0xb7 0x0b 0x24 0x53 0x00 0x00 0x00 0x00 0x16 0x6e 0x03 0x00 0x00 0x00 0x00 0x00 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1a 0x1b 0x1c 0x1d 0x1e 0x1f 0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2a 0x2b 0x2c 0x2d 0x2e 0x2f 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37 Sent 111 byte parcel: 0x08 0xbf 0xe0 0x12 0x71 0x00 0x00 0x60 0x10 0x0e 0x80 0x18 0x9e 0x52 0x54 0x00 0x5c 0x97 0x46 0x5c 0x5e 0xab 0x0b 0x6e 0x7e 0x08 0x00 0x45 0x00 0x00 0x54 0x81 0xcb 0x40 0x00 0x3e 0x01 0x1c 0xb8 0x5b 0xc6 0x78 0x18 0xc2 0x64 0x07 0xe3 0x08 0x00 0x47 0xbf 0x0e 0xa4 0xed 0xfc 0xb7 0x0b 0x24 0x53 0x00 0x00 0x00 0x00 0x16 0x6e 0x03 0x00 0x00 0x00 0x00 0x00 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1a 0x1b 0x1c 0x1d 0x1e 0x1f 0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2a 0x2b 0x2c 0x2d 0x2e 0x2f 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37 TAZ-TBB-0(mec-pe1-re0.hel.fi vty)# test jnh 0 packet-via-dmem disable TAZ-TBB-0(mec-pe1-re0.hel.fi vty)#

So the format is test jnh (mq_where_interface_is) packet-via-dmem capture (16_bit_type_mask_in_hex) (up-to-8-bytes-pattern) (optional offset from start of the packet) you should use mask 0x3, in my test test bits 1 and 2 are production traffic, bits 10 and 15 are some crap, and others are just some types I don't seem to be using on my boxes

Unlike in PFC3, we capture many packets, and list is constantly updated until you stop the capture. This is very nice when you're not exactly sure what you're looking for and you know your trigger will also match packets you don't care for. We also easily see both packet received and packet send, so we can be sure the traffic is arriving to the box, from MAC addresses we can determine how and where and sent parcel gives us high degree of confidence the packet is leaving the box.

I don't know what the dispatch cookie means, nor what the first 6 bytes in the received parcel or the first 13 bytes in the sent parcel. I'm guessing that is some internal metadata, quickly trying to check for stream ID in MQ and IX or IFL and IFD numbers I can't find a match for them. But I'm mostly interested in just seeing that the packet came in from expected DMAC+SMAC and went out with expected DMAC+SMAC. Would be very useful to be able to at least extract somehow ingress and egress port information (MQ, IX, port, IFL, IFD, anything).

If you're capturing on box with multiple MQ and fabric then you won't see sent parcel having the rewrite information (but you'll see more metadata), you need to jump on the egress MQ to catch rewrite information. If you are having trouble reading the hexdump you can always use 'text2pcap' from wireshark to turn it into PCAP file and browse it in wireshark. Lot more playing around is needed to understand parcel types, cookie, metadata and use in multiple MQ scenario.

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