SOTL wrote:
>Switch
>Non configurable
>If an input package only goes to the port that contains the device that the
>package is directed to. Can not figure this one out how the switch knows to
>sent a package inputed to A to output B instead of C and what happens if you
>need it to also go to D?
>
>
My understanding of switches is that they maintain an internal database
that logs things like <pseudo> "in port 1, I have a device with mac
address xx:xx:xx:xx:xx:xx" </pseudo> So when your PC, plugged into
port 2, wants to print to the printer in port 1, the switch goes "oh, I
recognize the PC in port 1 with mac address blah, blah is sending data
packets addressed to a device that I have in my database as being
plugged into port 2, let me make a direct connection between those two
ports to reduce traffic across the network. I think the reason they
call them switches is because they work just like the old telephone
operators did... they directly connect this phone to that one via a
switching board. But the key to the whole technology is that they
maintain an internal database.
I have to agree with Paul's earlier comment about routers..... I think
you are confusing firewalls with routers. All routers do is determine
if packets should stay on the local subnetwork, or pass to a different,
connected subnetwork. Like so...
LAN A ------- Router -------- LAN B
If a PC on LAN A is printing to a printer also on LAN A, then the
packets hit the router... the router says "according to the packet
destination (LAN A), I won't let this packet cross the router to LAN
B" However, if that PC is sending an email with packets destined for
an email server on LAN B, the packets hit the router and the router
allows it to pass because the destination was not local.
That was a very simplistic explaination, and I'm sure many people can
shoot holes in what I explained above.... but essentially, routers just
limit traffic. You don't want LAN traffic crossing the WAN. "Don't
span the WAN" was the common saying when I studied this stuff.
I'm pretty sure that what you were saying in your previous email was
firewalling.. That's saying something like... all traffic that hits port
80 on the gateway, redirect that to 192.168.0.5:80. block all traffic
on port 21 etc...
-----------------------------------------------------------------------
This list is provided as an unmoderated internet service by Networked
Knowledge Systems (NKS). Views and opinions expressed in messages
posted are those of the author and do not necessarily reflect the
official policy or position of NKS or any of its employees.
This archive was generated by hypermail 2.1.3 : Fri Aug 01 2014 - 20:14:48 EDT