Internet connection problem

[Terry A. Haimann]

I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can connect
to mediacom, but mediacom announces the dns address at connect time. The
hub computer has the address somewhere, but the client boxes
don't. Therefore none of my client boxes can reach the web, because they
don't know what the current dns address is. My client machines are as
follows:

1. WinXP
2. Fedora Core 1
3. Win-ME (via Win4lin)
4. Win-98

I am assuming that I am going to have to set up a dns server on the rh 8.0
box, but I don't have the faintest idea how and what kind of script will
be necessary.

Terry

[Vance Howard]

Post by Terry A. Haimann
I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can connect
to mediacom, but mediacom announces the dns address at connect time. The
hub computer has the address somewhere, but the client boxes
don't. Therefore none of my client boxes can reach the web, because they
don't know what the current dns address is. My client machines are as
1. WinXP
2. Fedora Core 1
3. Win-ME (via Win4lin)
4. Win-98
I am assuming that I am going to have to set up a dns server on the rh 8.0
box, but I don't have the faintest idea how and what kind of script will
be necessary.
Terry

Why not google for internet connection sharing in RH8.0. You might be
suprised what you find.

[Randy McLaughlin]

Post by Vance Howard

Post by Terry A. Haimann
I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can connect
to mediacom, but mediacom announces the dns address at connect time. The
hub computer has the address somewhere, but the client boxes
don't. Therefore none of my client boxes can reach the web, because they
don't know what the current dns address is. My client machines are as
1. WinXP
2. Fedora Core 1
3. Win-ME (via Win4lin)
4. Win-98 I am assuming that I am going to have to set up a dns server on
the rh 8.0
box, but I don't have the faintest idea how and what kind of script will
be necessary.
Terry

Why not google for internet connection sharing in RH8.0. You might be
suprised what you find.
--
Nobody really cares if you're miserable, So you might as well be happy.

One quick and dirty answer is to plug in the DNS addresses into all of the
boxes. A better way is to do your own DNS with your linux box (don't use an
old version of named).


Randy

[Terry A. Haimann]

I am running iptables now for a firewall, what changes would I have to
make to the following:

# remove any existing rules
# This is a basic script that I modified from a Red Hat Linux for Dummies.
iptables --flush
iptables --flush -t nat
iptables -X

# deny all traffic to start
iptables --policy INPUT DROP
iptables --policy OUTPUT DROP
iptables --policy FORWARD ACCEPT

# allow all internal traffic
iptables -A OUTPUT -j ACCEPT -o lo
iptables -A INPUT -j ACCEPT -i lo

# allow all internal network traffic
iptables -A OUTPUT -j ACCEPT -o eth0
iptables -A INPUT -j ACCEPT -i eth0

# allow outgoing internet traffic on eth1
iptables -A OUTPUT -o eth1 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT

# use nat
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

Post by Terry A. Haimann
I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can connect
to mediacom, but mediacom announces the dns address at connect time. The
hub computer has the address somewhere, but the client boxes don't.
Therefore none of my client boxes can reach the web, because they don't
1. WinXP
2. Fedora Core 1
3. Win-ME (via Win4lin)
4. Win-98
I am assuming that I am going to have to set up a dns server on the rh 8.0
box, but I don't have the faintest idea how and what kind of script will
be necessary.
Terry

I think it would be easiest to pick up a cheap router with firewall and
connect all the machines to the router.
Are you using the RH8 box a the dial up server for the other machines now?
I think need to enable Iptable NAT and Forwarding on
the RH8 box. You can assign static or keep your current static Private
addresses but the gateway address on your client machines should point to
the hub. You can have the hub assign addresses by dhcp but in small
networks that's a overhead you really don't need, unless of course you
just want to learn how to do it.
I could try explaining this in detail but there are lots of better
http://www.yolinux.com/TUTORIALS/LinuxTutorialIptablesNetworkGateway.html

[Terry A. Haimann]

I am running iptables now for a firewall, what changes would I have to
make to the following:

# remove any existing rules
# This is a basic script that I modified from a Red Hat Linux for Dummies.
iptables --flush
iptables --flush -t nat
iptables -X

# deny all traffic to start
iptables --policy INPUT DROP
iptables --policy OUTPUT DROP
iptables --policy FORWARD ACCEPT

# allow all internal traffic
iptables -A OUTPUT -j ACCEPT -o lo
iptables -A INPUT -j ACCEPT -i lo

# allow all internal network traffic
iptables -A OUTPUT -j ACCEPT -o eth0
iptables -A INPUT -j ACCEPT -i eth0

# allow outgoing internet traffic on eth1
iptables -A OUTPUT -o eth1 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT

# use nat
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

Post by Terry A. Haimann
I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can connect
to mediacom, but mediacom announces the dns address at connect time. The
hub computer has the address somewhere, but the client boxes don't.
Therefore none of my client boxes can reach the web, because they don't
1. WinXP
2. Fedora Core 1
3. Win-ME (via Win4lin)
4. Win-98
I am assuming that I am going to have to set up a dns server on the rh 8.0
box, but I don't have the faintest idea how and what kind of script will
be necessary.
Terry

I think it would be easiest to pick up a cheap router with firewall and
connect all the machines to the router.
Are you using the RH8 box a the dial up server for the other machines now?
I think need to enable Iptable NAT and Forwarding on
the RH8 box. You can assign static or keep your current static Private
addresses but the gateway address on your client machines should point to
the hub. You can have the hub assign addresses by dhcp but in small
networks that's a overhead you really don't need, unless of course you
just want to learn how to do it.
I could try explaining this in detail but there are lots of better
http://www.yolinux.com/TUTORIALS/LinuxTutorialIptablesNetworkGateway.html

[Moe Trin]

Post by Terry A. Haimann
I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can connect
to mediacom, but mediacom announces the dns address at connect time.

Idiots! The IP address of a name server has to be reasonably constant
so that it can be found. There should be no reason for someone to be
playing "musical IP addresses" with this. Looks as if your "only choice"
is a bunch of technical incompetent fools.

Post by Terry A. Haimann
The hub computer has the address somewhere, but the client boxes
don't. Therefore none of my client boxes can reach the web, because they
don't know what the current dns address is. My client machines are as
1. WinXP
2. Fedora Core 1
3. Win-ME (via Win4lin)
4. Win-98

Oh crap. Windoze boxes are extremely chatty, always trying to find new
hosts to drop their pants in front of. I'd strongly suggest setting up a
caching/forwarding nameserver on your RH box, and pointing everyone else
at it.

[compton ~]$ zgrep -w bind rpms.8.0-i386.gz | sed 's/^.*0 //'
1818173 Sep 03 21:10 bind-9.2.1-9.i386.rpm
875526 Sep 03 21:10 bind-devel-9.2.1-9.i386.rpm
698279 Sep 03 21:10 bind-utils-9.2.1-9.i386.rpm
201374 Sep 03 21:36 redhat-config-bind-1.8.1-18.noarch.rpm
[compton ~]$ zgrep name rpms.8.0-i386.gz | sed 's/^.*0 //'
6988 Sep 03 21:10 caching-nameserver-7.2-4.noarch.rpm
[compton ~]$

You also want to look at a couple of HOWTOs:

91563 Dec 23 2001 DNS-HOWTO
287057 Jul 23 2002 Security-Quickstart-Redhat-HOWTO

Post by Terry A. Haimann
I am assuming that I am going to have to set up a dns server on the rh 8.0
box, but I don't have the faintest idea how and what kind of script will
be necessary.

The stuff that comes with the 'caching-nameserver' package should tell
you what you need. You really should set it up so that you are
authoritative for your own hosts (the world won't know what their names
are, so you will need to be "correct"),

I'm sure you are aware that RH8.0 has been unsupported since 2003, and
really shouldn't be exposed any more.

Old guy

[Kurt von Finck]

Post by Moe Trin
Oh crap. Windoze boxes are extremely chatty, always trying to find new
hosts to drop their pants in front of.

Classic.

./k

[Tim]

Post by Moe Trin

Post by Terry A. Haimann
I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can connect
to mediacom, but mediacom announces the dns address at connect time.

Idiots! The IP address of a name server has to be reasonably constant
so that it can be found. There should be no reason for someone to be
playing "musical IP addresses" with this. Looks as if your "only choice"
is a bunch of technical incompetent fools.

It's quite common for ISPs to tell you what DNS server to use as you
connect, some do rotate several of them amongst their users (I'm told) to
spread the load around. You are told it as you connect, at the same time
that you're assigned your own IP, and it's a quite well known procedure, so
it *can* easily be found. You don't need it when you're not connected.

A problem with that is the seemingly poor support for dynamic IPs with
Linux (they're something that's been around for quite some time). If I
configure my gateway box to use its own DNS server, the dialup connect
script will often usurp it with the dynamically discovered ISP's DNS
servers (rather than add them to the list, it puts them at the top).

[Moe Trin]

Post by Tim
It's quite common for ISPs to tell you what DNS server to use as you
connect, some do rotate several of them amongst their users (I'm told) to
spread the load around.

The 'tell you at connect time' is a function of the windoze philosophy of
minimizing the technical requirements of the user. Plug it in, and it just
magically works. This is also an advantage if you are moving your computer
from network to network (example, home to work, and vice-versa). It's often
considered a security problem (where have you _ever_ heard that about a
microsoft concept), as it's not under control of the user.

It's not very likely for the ISP to be playing "musical IP addresses" with
the DNS servers - as there really is some work needed to set up a server.
Once done, there is no reason to tear it down, and rebuild it again for a
whim. Load sharing is used, but DNS is not a CPU or bandwidth intensive task
(as compared to for example, a web server).

Post by Tim
A problem with that is the seemingly poor support for dynamic IPs with
Linux (they're something that's been around for quite some time). If I
configure my gateway box to use its own DNS server, the dialup connect
script will often usurp it with the dynamically discovered ISP's DNS
servers (rather than add them to the list, it puts them at the top).

That depends on the tool you are using to connect. For dialup, what you
are actually using is pppd and that definitely does NOT mess with
/etc/resolv.conf (see the man page). "Helper" tools like kppp may alter
/etc/resolv.conf, but that's easy to fix/prevent. (I put the word "Helper"
in quotes, because they also hinder as much as help, and tend to confuse
things.) If you are connecting via Ethernet (cable or DSL, but also for
many home network setups), the name server setup is controlled by the DHCP
server (meaning extra work for whoever set it up), and whatever client you
are using.

Very few of our systems ever move, so we spend the extra minute or so when
installing them to set them to static addresses. With RFC1918 (which replaced
RFC1597 from 1994) providing nearly 17.8 million usable IP addresses, the
original rational for DHCP (lots of computers, not many addresses - see
RFC0951 from 1985) hasn't existed for ten years. The only remaining reason
for it to exist is the consumer market where the user is almost always
lacking any technical knowledge, and depending on "expert" systems to make
up for it. But the expert systems are only as good as the person who set
them up.

Old guy

[Stefan Patric]

Post by Terry A. Haimann
I am in the process of upgrading my home network from a dial-up to
broadband account. The only choice that I have for a broadband account is
Mediacom in central Iowa. Now my hub computer (a rh 8.0 box) can
connect to mediacom, but mediacom announces the dns address at connect
time. The hub computer has the address somewhere, but the client boxes
don't. Therefore none of my client boxes can reach the web, because they
don't know what the current dns address is. My client machines are as
1. WinXP
2. Fedora Core 1
3. Win-ME (via Win4lin)
4. Win-98
I am assuming that I am going to have to set up a dns server on the rh
8.0 box, but I don't have the faintest idea how and what kind of
script will be necessary.

Do you really mean DNS? Or is it your IP address that is announced?
Normally, an internet provider's DNS(s) is constant, never changing,
but periodically changing a customer's IP address is the norm. With my
broadband connection, my IP address is changed at least every 3 days,
sometimes twice in 24 hours.

If you set up the RH 8.0 box as a router/gateway with a NAT (network
address translation) installed, and the other boxes as a local network
plugged into a switch or hub, the other boxes won't need to know the
DNS's of Mediacom or even the IP address. All they'll need to know is
the local network Gateway address, which you set and control, to access
the internet.

The easiest way to do all this is to buy a hardware router/switch that
has NAT and DHCP and firewall and proxy, etc. built-in instead of
trying to set it up yourself. That's what I did. Took about 30
minutes to have it up and running, and that includes unpacking the box
and reading the instructions.