Routing

 View Only
last person joined: 4 days ago 

Ask questions and share experiences about ACX Series, CTP Series, MX Series, PTX Series, SSR Series, JRR Series, and all things routing, including portfolios and protocols.
  • 1.  Way to know the source of L3 incomplete errors packets

    Posted 12-20-2023 13:30

    I need to know the way to capture the IP packet with the incomplete header in Juniper ? Would be helpful to see the source IP of the packet to identify its' origin.

    Juniper MX10003 is connected to Arista switch via 3*100G links . 

    root@MX10003-re1> show interfaces et-0/3/0 | match index

    Interface index: 367, SNMP ifIndex: 774

    IMPC0(MX10003-re1 vty)# show jnh ifd 367 stream

    bad-IPv4-len: 0000000000005114 pkts, 0000000000214788 bytes

    checksum: 0000000000005850 pkts, 0000000001307039 bytes

     

    Errors: 10964, Drops: 0, Framing errors: 0, Runts: 0, Policed discards: 0, L3 incompletes: 10964



    ------------------------------
    SUBHAJIT CHAKRABORTY
    ------------------------------


  • 2.  RE: Way to know the source of L3 incomplete errors packets

    Posted 12-20-2023 14:05
    Hi Subhajat,

    I’d recommend using the command ‘monitor traffic’ with the relevant information you have currently.

    More can be seen here:
    https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/command/monitor-interface.html

    From here, if you want to deep dive the packet inspection I’d look at saving the captured output and using Wireshark to analyse them.

    If your unsure how to do this, you can follow this guide here:
    https://www.juniper.net/documentation/us/en/software/junos/network-mgmt/topics/topic-map/analyze-network-traffic-by-using-packet-capture.html

    HTH,
    Ethan




  • 3.  RE: Way to know the source of L3 incomplete errors packets

    Posted 8 days ago

    Thank you. We suggested customer to perform port mirroring . But as it is LAG so ae contains 3*100G interfaces . it is not possible to mirror whole traffic until sender only send few traffic . So customer agreed with Juniper KB about L3 incomplete errors as there is no traffic impact due to this. 



    ------------------------------
    SUBHAJIT CHAKRABORTY
    ------------------------------