Junos tcpdump

Note Before:

Protocol delegation (Periodic Packet Management Daemon) is not compatible with the embedded tcpdump tool "monitor traffic interface ...". One cannot capture control plane packets that are managed by ppm man (on the LC CPU) or inline ppmd (on LC PFE). Disable ppm man and inline ppm by using the following config (this may have a performance impact on a busy device):

set routing-options ppm no-delegate-processing

set routing-options ppm no-inline-processing

MX480 example:

monitor traffic interface em0 extensive layer2-headers print-ascii no-resolve

15:13:04.706371 bpf_flags 0x81,  In
        Juniper PCAP Flags [Ext, In], PCAP Extension(s) total length 16
          Device Media Type Extension TLV #3, length 1, value: Ethernet (1)
          Logical Interface Encapsulation Extension TLV #6, length 1, value: Ethernet (14)
          Device Interface Index Extension TLV #1, length 2, value: 8
          Logical Interface Index Extension TLV #4, length 4, value: 3
        -----original packet-----
        02:00:01:00:00:04 > 02:01:00:00:00:05, ethertype IPv4 (0x0800), length 60: (tos 0x0, ttl  64, id 61838, offset 0, flags [none], proto: TCP (6), length: 40) 128.0.0.1.6166 > 128.0.0.5.55864: . 1752597432:1752597432(0) ack 2014946724 win 65535
0x0000   0201 0000 0005 0200 0100 0004 0800 4500        ..............E.
0x0010   0028 f18e 0000 4006 893b 8000 0001 8000        .(....@..;......
0x0020   0005 1816 da38 6876 83b8 7819 a5a4 5010        .....8hv..x...P.
0x0030   ffff b392 0000 0000 0000 0000                  ............

 

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