13 Oct
2011
13 Oct
'11
8:43 a.m.
At 10:05 AM 10/13/2011, Dennis Boone wrote:
grievous misunderstanding of the common "one
external IP address"
service. The device will hand you more than one internal IP. If it's
equipped with one port and not doing NAT, then it is expecting you to
supply a firewall device, not to plug directly into it. The firewall
device will then do NAT and hand you multiple internal addresses.
Yeah, well, the modem will still only bind to one MAC address until you
power-cycle them, and they'll still only hand out one address via
DHCP, and it'll be a 192.168.1.xxx. Go figure. This is true for
the ATT DSL and Charter Cable modems I see in my area.
Arguably it simplifies the situation for the one modem, one computer
user. It doesn't let you simply add a switch to connect multiple
devices. It lets the ISP upsell the consumer to a four-port
combo firewall/router/wireless/modem.
Even if you buy the business-class small-set-of-statics service,
I've yet to see either ISP properly deliver and configure a modem
that actually hands out those real statics. At that point they
figure you're either smart enough to do it yourself, or smart enough
to demand that the installer do you a favor. After all, there's still
the option of whether you want it to use DHCP to do it.
- John