Duck said:
Can I connect a switch to the ethernet port to allow many more PCs to connect to the internet? If I can then why do some people have a router between the modem and the switch? What does it do?
a very typical setup would be
Code:
modem --- (wan side) router (lan side)--- one or more systems
you can use a switch in place of the router *IF*
- you don't want NAT/SPI services
- you like to perform the setup yourself
you would be wise to always use a router even if there's only one system
attached, so as to have NAT and SPI features to protect you.
a router also provides DHCP service so that your LAN systems can automatically be configured, which a switch can no provide
frankly, I have this setup
Code:
modem --- (wan side) router (lan side)--- two systems
+
+
a switch
+
+ ---- two more systems
but this is strickly because I already had the switch AND it facilitated
the physical wiring. Notice the switch is on the LAN side and all systems
get NAT/SPI protection AND DHCP configuration services.
NAT: Network Address Translation
The public Internet is on the WAN side and your systems are on them LAN side.
This forces the router to perform tricks (which a switch or hub can not do) to ensure your LAN addresses can reach outbound but the hackers can not reach inbound.
SPI: Statefull Packet Inspection
Statefull says there is a specific sequence of events and a valid data stream
always starts in a well know condition; any data that has not started from that
condition is *known* to be bogus and the packet is discarded.
this is a very effective anti-virus, anti-trojan tool!
Conclusion: in my opinion, every hispeed broadband should be required to have a router immediatel attached to the modem.