Wireshark mailing list archives
Re: Should an IPv4 netmask be its own fieldtype?
From: mmann78 () netscape net
Date: Thu, 1 Oct 2015 08:35:04 -0400
But doesn't any of these potential representations (mostly network prefix) require a specific field type (and not a display type) for display filtering purposes? -----Original Message----- From: Jeffrey Smith <whydoubt () gmail com> To: Developer support list for Wireshark <wireshark-dev () wireshark org> Sent: Thu, Oct 1, 2015 1:46 am Subject: Re: [Wireshark-dev] Should an IPv4 netmask be its own fieldtype? RFC950: "Since the bits that identify the subnet are specified by a bitmask, they need not be adjacent in the address. However, we recommend that the subnet bits be contiguous and located as the most significant bits of the local address." So essentially any mask IS legal (even if not recommended). The two standard subnets notations are dotted decimal (e.g. 255.255.255.0) and network prefix (e.g. /24). So recognizing just "24" may not be terrible, but I find no precedent for doing so. On Sep 30, 2015 11:03 PM, "Guy Harris" <guy () alum mit edu> wrote: On Sep 30, 2015, at 9:00 PM, Evan Huus <eapache () gmail com> wrote:
A pure netmask (without an associated address) is representable as just a UINT8. Would it be terrible to write `protocolXYZ.netmask == 24`?
Some are sent over the wire as a 32-bit mask, which could, conceivably, have holes in the middle. ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: https://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: https://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
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Current thread:
- Re: Should an IPv4 netmask be its own fieldtype? mmann78 (Oct 01)
- Re: Should an IPv4 netmask be its own fieldtype? Evan Huus (Oct 01)