Wireshark · Wireshark-users: Re: [Wireshark-users] the Fragment offset field in IP packet should follow the Raw bitstream？

[Jaap Keuter <jaap.keuter@xxxxxxxxx>]

That was a nice bit of source code archeology, but I’ve found that this format was changed in commit 7f6d5c04a86 with the comment:

commit 7f6d5c04a869525d31e8d6e260d5195857481031
Author: Martin Mathieson <martin.r.mathieson@xxxxxxxxxxxxxx>
Date:   Wed Aug 29 15:35:27 2007 +0000

    Don't show fragment offset as a bit field, but note number of bits used in long text.
    
    svn path=/trunk/; revision=22727

Note the date, that was back in 2007, so this format disappeared before Wireshark 1.0.

Where did you get this from?

Thanks,

Jaap

On 19 Jun 2020, at 09:48, damker <damker@xxxxxxxx> wrote:

an IP packet decode As follows:

    ...

    Flags: 0x006b
        0... .... .... .... = Reserved bit: Not set
        .0.. .... .... .... = Don't fragment: Not set
        ..0. .... .... .... = More fragments: Not set
    ...0 0011 0101 1000 = Fragment offset: 856
    Time to live: 128

I know that it says "The fragment offset is measured in units of 8 octets (64 bits)" in RFC 791.

my question is: Flags = 0x006b, the "...0 0011 0101 1000 = Fragment offset: 856" should be "...0 0000 0110 1011 = Fragment offset: 856"?

I think the second one is more clear.

---

damker

 

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