Network questions

[RotorHead]

Ok, right now my network is using dynamic IP's on all my systems and my service provider is also using dynamic IP's

My question is: can I set up my local network to use static IP's while my router uses dynamic IP's to connect to the internet?

[Ugly n Grey]

Yes you can if your router supports a static IP table where the internal machines are currently getting IP's via DHCP, you would allocate those IP's manually to the internal network and usually enter those IP's into a table to prevent the router from hanfing them out to something you might plug in.

My question is...why bother? Most of the time the IP assigned internally is leased for so long, it never changes anyway...

Regards
Ugly

[sodface]

Yes. The WAN interface of the router that plugs into your cable modem will be assigned the dynamic IP from the ISP. The LAN side of the router is in the same range as your network and usually defaults to 192.168.0.1 or something similar. If you disable DHCP on your network machines, just assign each a unique address in the 192.168.0.xxx range with a subnet mask of 255.255.225.0. Also determine your DNS server addresses and fill those in or you won't be able to resolve domain names to IP addresses. If you do an "ipconfig /all" command from a command prompt, you can get the DNS addresses from there. They shouldn't change even though your external IP address may change from time to time.

Set your default router address to the local network address of the router, the 192.168.0.1 address or similar discussed above.

That should be it. I'm running static IP's myself now and haven't had any problems.

[sodface]

My question is...why bother? Most of the time the IP assigned internally is leased for so long, it never changes anyway...


I agree, the only reason I went to statics was that my old Netgear router let me reserve an IP for a specific MAC address. That way when I configured the router to forward Port 80 traffic to a specific IP address, I knew it was going to a specific box (my web server) and not some other box that wouldn't know what to do with it. I replace my Netgear with a Linksys router and I can't find a similar option available with it - that is, using DHCP but reserving a specific IP for a specific MAC.

So I switched to static IP's. I realize now that you can also use a combination of both static and DHCP assigned addresses. If you make any static IPs lower than the starting address of your DHCP range then you won't run into any conflicts.

[RotorHead]

My main reason for wanting to do this is that I installed VNC on all my systems, and occasionally the router would reassign IP's, so I would get confused on which box I was connected to. This normally happens when we lose power during storms. Then I’d have to walk all the way up stairs and figure out what machine is on what IP.

The other reason is to prevent my kids from connecting to other wireless networks when they get Internet access taken away for bad behavior (which is a social death wish for a teenager)

Ok next question, Do I have to use the default gateway and subnet mask for this or can I pick one as long as it is in the correct range …..?

[Ugly n Grey]

you have to use the correct gateway (router ip) and correct subnet mask (depends on what you assign for a subnet series, most commonly 255.255.255.0)....

[RotorHead]

Cool, so as long as I use the same settings through out, then I'm good right.

Next up is :

DHCP server.....this is my router or gateway yes? Which I can change to whatever I want

DNS server .....This is my ISP Yes? Do I need to input these in the TCP/IP settings on each machine, or just in the router?

[sodface]

DHCP server.....this is my router or gateway yes? Which I can change to whatever I want

Yes, and yes as long as the router and network comps are all using the same IP range and subnet mask (all on the same logical network). And don't forget to actually turn off DHCP on the router or you'll be using statics with the option of getting an IP automatically. Though It would be your neighbor's DHCP that your kids would be using though so it wouldn't have much effect. You'd have to block them from having access to TCP/IP properties I guess so they couldn't change it to DHCP from static.


DNS server .....This is my ISP Yes? Do I need to input these in the TCP/IP settings on each machine, or just in the router?
I input on each machine. Usually the router will get DNS addresses from the ISP which it in turn (the router) passes along with an open IP address when it gets a DHCP request. I think the spot where you can set them manually in the router is if you want to override the ISP DNS servers and pass on your own when a DHCP request is received. Again, I'm pretty sure this is still for DHCP, if you are not using it then you'll have to set them manually in the TCP/IP property window on each computer.

[RotorHead]

Great, thanks guys. :rock:

All this plug and play stuff makes it to easy to forget how all this stuff is done. :lol:

The main purpous for all of this is to help get a little more control over my network and to help improve the security just little more.