2

I'm trying to ping an ECU, both PC and ECU have static IPV6 address the problem is that the target address (ECU) pinged is different from the one caught by Wireshark

subnet : 64

ping command

$ ping -6 fd53:7cb8:383:eb03:0:0:0:100

Pinging fd53:7cb8:383:eb03::100 with 32 bytes of data:
Destination host unreachable.
Destination host unreachable.
Destination host unreachable.
Destination host unreachable.

wireshark trace

Internet Protocol Version 6, Src: fd53:7cb8:383:eb03::104, Dst: ff02::1:ff00:100
    0110 .... = Version: 6
    .... 0000 0000 .... .... .... .... .... = Traffic Class: 0x00 (DSCP: CS0, ECN: Not-ECT)
    .... .... .... 0000 0000 0000 0000 0000 = Flow Label: 0x00000
    Payload Length: 32
    Next Header: ICMPv6 (58)
    Hop Limit: 255
    Source: fd53:7cb8:383:eb03::104
    Destination: ff02::1:ff00:100
Internet Control Message Protocol v6
    Type: Neighbor Solicitation (135)
    Code: 0
    Checksum: 0x569e [correct]
    [Checksum Status: Good]
    Reserved: 00000000
    Target Address: fd53:7cb8:383:eb03::100
    ICMPv6 Option (Source link-layer address : 00:e0:4c:23:01:d3)
        Type: Source link-layer address (1)
        Length: 1 (8 bytes)
        Link-layer address: RealtekS_23:01:d3 (00:e0:4c:23:01:d3)

PC configuration

enter image description here

  • Hi Makhlouf and welcome. What's an ECU? Also, it's much better to copy+paste than insert images here, as it means everything gets searched and indexed properly. – jonathanjo Dec 20 '18 at 15:46
  • Please use plain text instead of images to post output of your commands, you can use { and } for that. – Teun Vink Dec 20 '18 at 16:00
5

What you're seeing is the Neighbor Discovery Protocol which in IPv6 replaces ARP. You can see that data is ICMP , and the destination address is a Solicited Node addresses. You can read more about it at this page from Cisco.

  • yes, now I understand NDP. but why can't see the ping packet? should the target respond first to the NDP? – Makhlouf GHARBI Dec 20 '18 at 15:59
  • Yes, so the sender can get the MAC address. Since it never gets a reply to the ND, it never sends the echo request – Ron Trunk Dec 20 '18 at 16:15

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