> On Mar 21, 2022, at 12:21, Bjørn Mork <bj...@mork.no> wrote:
>
> Owen DeLong via NANOG <nanog@nanog.org> writes:
>
>> Virtually every useful flow of packets in one direction requires a
>> relatively symmetrical flow of packets in the other direction.
>
> Packet captures are useful without anything being returned. It's not
> uncommon to use some sort of unidirectional tunnel to transport captures
> over an IP-network.
By definition, packet captures can’t be more than 50% of useful traffic and the
traffic they are capturing is almost certainly a bidirectional flow of some
form.
I’m willing to bet that packet captures are well below 1% of all traffic.
I’m willing to bet that less than 25% of all packet captures are transported
Over unidirectional tunnels, though I admit I could be wrong about this.
> Same goes for logging. Traditional udp syslog is a one-way street.
True, but most environments I’m familiar with have been moving away from syslog
in favor
of some form of guaranteed delivery, which requires a two-way street.
Also, if a significant fraction of your traffic is logging, you’re probably
doing something wrong.
(Note the word “Virtually” in “Virtually all”).
> And I'm sure there are more examples.
Perhaps, but I still say that in terms of overall total traffic, they are
mostly a rounding error.
> Not that I think it matters in this discussion, which appears more
> circular than bidirectional.
That’s probably fair.
Owen
