2615Re: Segments with no flags set
- May 30, 2001bryan@... writes:
> I recently encountered an interoperability problem between a firewall and aI don't see how it could be illegal, if the ACK flag bit is clear this
> Voice-over-IP hardware device (with embedded TCP stack), where the VoIP box
> would begin to send segments with no flags set (including ACK) over an
> established session. Although I've never observed such use of TCP before,
> I can't find hard evidence that indicates it is a violation of spec. Can
> anyone confirm if this is truly against the law?
simply means to ignore the ACK field.
I suppose a firewall vendor could claim that this provides a 32-bit
field in which to create a covert channel of information, but the URG
field can already be (and honestly, by hardcore crackers probably is)
used for this purpose :-)
David S. Miller
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