On Mar 21, 2022, at 12:21, Bjørn Mork <bjorn@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