IP Addresses and Subnet Masks

[dazaau]

Hi everybody,
I have a FC4 Box as a file server and IPcop as my router and I am still using the old IP of 192.168.X.X and subnet of 255.255.255.0 stuff. I am looking to move to something more exotic and was wondering if any of you knew a good source to learn how these work and better ways to set them up. :)
Thanks!
Daniel

[ppesci]

If your configuration works for you then fine.There is no OLD 192.168.X.X.

Go to Linux Documentation Project and look for Networking for more information about how TCP/IP works and some less bored configurations.

http://tldp.org/

Pietro Pesci Feltri

[dazaau]

where exactly would I find this info? I didn't see anything and a search for networking came back empty. I mean old as in ordinary. Everybody uses it and I think it would be more secure to use somehting else, and I beleive if you know what you are doing you can do some pretty interesting stuff

[w5set]

Old IP's?
Well, ain't any new one's except the IPV6 stuff.
http://www.faqs.org/rfcs/rfc3330.html
Seems most PRIVATE, nonroutable addresses come from the 10.0.0.0 or 172.16.0.0 or 192.168.0.0 blocks that have been set aside just for that use.
Any other use then those for a personal computer might just go through your router/modem and out into cyberspace when you were just trying to access your local network file server.
And if your modem/router is sending these (very unlikely) local network addresses (nonroutable IP's) out onto the internet in any quantity--more then likely your ISP will be getting in touch with you soon.
It has been setup this way for several years now and except for the shortfall of available IP's (public IPV4) it has been a good plan more/less.

[Skunk Worx]

i think you are saying "well, my router defaults to setting all my machines up as 192.168.1.x so i could get scanned for that because everyone uses those".

In a sense, you are right. you are trying something called "security through obscurity". You could set your IP range to another private network address scheme, like "10.99.97.x" and unless some got in and scanned for those, they would not see them.

It's considered a poor security model though. Better to keep things up to date, remove unneeded services, etc. And the netmask is more related to the number of machines on your subnet.

try http://www.tldp.org/

[w5set]

I really don't think anyone is going to scan your IP (private ranges) from the internet--i.e. 192.168.?.?
They are dropped by the internet/ISP routers about instantly.
Read about NAT.

[Skunk Worx]

I really don't think anyone is going to scan your IP (private ranges) from the internet--i.e. 192.168.?.?
They are dropped by the internet/ISP routers about instantly.
Read about NAT.

If you read my post more carefully, I say "if someone gets in". That does not mean "from the internet".

[w5set]

Wasn't meant for you Skunk Worx, you are already aware of all this network/IP stuff and use it--like maybe for a living?
But if an intruder was capable of scanning inside his network any IP used would be a moot point.
Currantly (local innermost IP range) I am at 192.168.2.102 HWaddr 00:15:f2:02:c4:bc (spoofed cuz it's really HWaddr 00:E0:29:50:0B:98)
But my public IP is NAT'ed by a modem and then a router/firewall and then another router.
As you can see from the above circuit of routers--I am aware of what could happen if someone was in and able to do a local scan or jack an ARP table.
But I don't worry about using the "little" more/less default 192.168.x.x local lan IP settings, if someone can read those--there is a larger problem then which range to use.

[dazaau]

well, I am not worries about people getting in from the internet. I was just wondering about using a different set of IP address and subnet masks. Apparently you can use different ones like 10.XX.XX.X and it will alow less physical addresses so instead of 255 possible connections ther would only be 30. I am also interested in the possibility of running 2 "networks" over one physical hardware lan. for instance one have a subnet of 255.255.255.0 and one have a subnet of 255.255.0.0 . One for internet access and one for lan access to my file server. I don't even know how possible all this is but I would be interested to learn more about IP and how it works...
So anyone got some links :-)

[Skunk Worx]

w5 : oh ok, gotcha.

daz: try googling for things like "LAN, DMZ, multiple subnets"...there is SO much information out there. A lot of the small home routers have a DMZ built in now, but they have their limits.

The links already provided have a lot of network design info on them.

---
John

[w5set]

http://www.faqs.org/docs/Linux-mini/IP-Subnetworking.html
http://tutorials.freeskills.com/read/id/283/headline/TCPIP+Networking+-+IP+Addressing
http://compnetworking.about.com/od/workingwithipaddresses/a/ipaddresses.htm

[Skunk Worx]

also google :

http://www.google.com/search?hl=en&q=linux+networking+DMZ+site:tldp.org

[dazaau]

Thankyou Thankyou :-) Time for some reading!

Really appreciate the help!

[w5set]

Google is used by just about everyone I guess. (I did a google on "networking + ip" and those were just a few of the Results 1 - 10 of about 117,000,000 for networking + ip. that it came up with--happy reading.
It's the only one I use and it's embedded into my browser (Linux Firefox) even.
Usually I am rather cautious about browser "helpers" after a lot of years of Windoze incidents--but not with Google, even though they do use the "stuff" you search for for $$$$ reasons. heck--even those 2 very wealthy young fellers need to make a buck every once in a while--hi--hi

[dazaau]

does anyone not use google? I think they pretty much own the internet :-)

[Zigzagcom]

For something exotic, you could try to get APIPA with 169.254. working. It has always been a mystery to me.