[ntp:questions] OT: GPS18x LVC failure
Uwe Klein
uwe_klein_habertwedt at t-online.de
Wed Oct 14 21:49:27 UTC 2009
Rick Jones wrote:
> Uwe Klein <uwe_klein_habertwedt at t-online.de> wrote:
>
>>then:
>>some pakets are sent as broadcast to all ports.
>>switches store for each port the MAC addresses seen.
>>I have no idea if modern switches do (r)arp queries to
>>find the port a target MAC is sitting on or just broadcast
>>unknown MACs.
>
>
> Do you mean "flood?" Broadcast implies ff:ff:ff:ff:ff:ff destination
> MAC.
Most certainly not.
A switch (usually) forwards packets from one port to _one_ other
port ( the one were the switch has seen the target MAC )
( exempt are broadcast and multicast packets. )
Now if there is no entry for the target MAC the thing to do is
either forward this packet to all ports or start a reverse arp
cycle.
uwe
>
>
>>Hail for the times hubs were dumb repeaters with neither memory nor
>>intelligence ;-)
>
>
> Indeed :) Of course, then we'd be complaining about variability in
> back-off times and capture effect and whatnot instead :)
Someone sent me a copy of the unix haters handbook today.
Nothing better than having a target for good ol bitching.
uwe
More information about the questions
mailing list