gpg: failed to create temporary file '/var/lib/lurker/.#lk0x57275100.hantslug.org.uk.23306': Permission denied
gpg: keyblock resource '/var/lib/lurker/pubring.gpg': Permission denied
gpg: Signature made Sun Jan 3 21:54:31 2010 GMT
gpg: using DSA key 20ACB3BE515C238D
gpg: Can't check signature: No public key
On Sun, Jan 03, 2010 at 09:38:11PM -0000, Rob Malpass wrote:
> From: "James Courtier-Dutton" <james.dutton@???>
> To: "Hampshire LUG Discussion List" <hampshire@???>
> Sent: Sunday, January 03, 2010 3:09 PM
> Subject: Re: [Hampshire] NAS devices and MTU
>
> >Do you know the difference between a hub and a switch? Replacing hubs
> >with switches will greatly reduce the amount of traffic on each
> >network link.
>
> Hubs work at one speed, switches work at the most appropriate speed - that's
> the
> difference isn't it?
Nope. A hub is an all-to-all connection, so traffic sent to one
port of a hub comes out of all of the others. A switch is a
point-to-point connector, so it examines the ARP traffic that passes
through it, and sends packets to the most appropriate output port.
The upshot of this is that a hubbed network will cause packet
collisions betwen unrelated hosts on the network, so A talking to B,
and C to D will result in packets being dropped and retransmitted. A
switched network will allow those two conversations to continue
without interfering with each other.
Another thing is that most hubs I've encountered are half-duplex,
and most switches are full duplex. Half-duplex connections allow
packets going in opposite directions to interfere with each other,
which also kills network performance.
Hugo.
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- Be pure. Be vigilant. Behave. ---
