Re: home lan setup suggestions

David Millen ha scritto:
On 01 Feb 2008 21:47:20 -0600, comphelp@xxxxxxxxx (Todd H.) wrote:



Before you plug either into the internet, be aware of a current issue
with Flash that's making exploiting of UPnP rather common right now,
so whatever you do, you'll want to make sure you get updated firmware
for your router, set an administrative password, and disable UPnP
before you stand em up on the net and do a bunch of web browsing from
behind em.

I did my homework and shut off upnp on every machine I have, plus some services like remote registry/desktop and such (win xp)


1st config- modem is set to pppoe-bridging with dhcp on (in pppoe mode
it can't be turned off) , router's internet connection dialog set to
auto-dhcp.
Router internet config dialog shows:
Connection : Auto-dhcp
IP address : 192.168.1.1
Subnet : 255.255.255.0
Default gateway : xxx.xxx.xxx.N+1 , being the IP assigned by ISP
xxx.xxx.xxx.N
Modem manages the connection/disconnection to internet, being still
accessible trough browser at 192.168.0.1 (this puzzles me because i
though it wasn't going to work, since router's gateway is set to
another ip)

The router itself uses the gateway IP given to it by the ISP. It uses
it as the default next hop it's gonna send outgoing traffic to on the
WAN interface.

Your LAN devices will use your router's IP as their default gateway.


That is what I don't understand, see if this makes sense.
Router's gateway should be the modem, and modem's gateway should be the ISP's, so router dialog should tell me its gateway is 192.168.0.1 .
This is what happens if I unplug the phone cable from the modem: no internet connection, no assigned IP from ISP, router tells me its gateway is 192.168.0.1, very reassuring.
Then I plug in the phone cable, modem hooks up with dsl signal, gets its dynamic IP 200.100.50.50 .
At this point router changes the parameters shown, and tells me gateway is 200.100.50.51 .Same scenario as above.
If I traceroute traffic, it shows the obvious 192.168.1.1 - 192.168.0.1 - ISP machines - whatever route to target.
This makes total sense.
So where is 200.100.50.51? What is that?
The only idea I can come up with is "dynamic Ip + 1" is the address assigned by modem's dhcp to router's wan port in the mini-lan connecting the two devices.Mini lan that should be the 192.168.0.X subnet (thus I am able to access modem config with browser, pointing it at 192.168.0.1), while my pc's+router lan is the 192.168.1.X subnet.
Still router should tell me its gateway is 192.168.0.1 as shown in the traceroute.
Router's gateway address is router's wan port IP?
Modem's IP (on my side) is both 192.168.0.1 and 200.100.50.51? (this makes no sense at all)
D'oh.



2nd config- modem is set to rfc-bridging, this turns off modem dhcp,
router internet connection set to pppoe.
This way router manages connection/disconnection to internet, and
modem is no longer accessible at 192.168.0.1
Router internet config dialog shows:
Connection : PPPoe
Ip address: ip assigned by ISP
Subnet: 255.255.255.255
Default Gateway : ISP's gateway

There's an option for connecting the router to a static Ip (which is
obviously not my case) but i tried to set static IP to 192.168.0.1
just to see what happened... didn't work.
I think that setup may have bridged your entire lan right onto the
internet. You'd have to get multiple-IP support from your broadband
provider for it to work, and your lan machines would contact the isp
dhcp server for addresses, if the multiple-ip broadband plan didn't
come with static IP's for you to assign your machines.

You probably really dont' want to be bridging your machines on the
internet.

My limited knowledge suggests me 1st is better (lan before router -
lan between router and modem - internet , maybe?), but i can't tell
the difference between a wan port and my butthole, so I confide in
your experience.
Thank you.
Your gut guides you well.

I probably know even less than the OP professes to, but my setup is
similar to his number 2 config. My flaky understanding is that the
broadband modem is effectively just presenting the broadband
connection to the router, which has its own firewall and NAT inbuilt
so that the baddies can't get in. Is that wrong?

The only issue I have with the arrangement is that I can't get at the
modem from a machine on the LAN to see stats, configure it, etc,
unless someone knows an easy workaround?

My same reasoning, with second config router and modem should work as a single device, like they were a router with built in dsl modem (phone jack instead of wan port)

Still I configured network as suggested by Todd, thanks mate.
.

Loading