Going broadband! Help config eth0/1 and ppp0.

I've got a working RHL 7.2 system. It's running as a server with DHCP,
caching DNS, Samba, and iptables firewall for a couple Win boxes. I
currently connect to Mindsproing via an analog modem as ppp0. The
connection to my internal network is via the motherbd's built-in 10/100
(eth0). I'm going to switch ISPs to Comcastrate broadband, which means
another NIC (3Com 3c509) to connect to whatever cable modem box they
decide to rent to me. Layout prevents me from using USB from the cable
modem to the server. I just installed the new NIC card, and the RHL
Hardware Browser seems to detect it as a "3C509 100BaseTX (Boomerang)".

I would _like_ (ahem) the option of keeping the analog modem attached for
when (not if) I have problems with the cable modem connection.

1. What do I need to do to have the existing ethernet (82557/8/9) remain
as eth0, and enable the second (3Com) card as eth1 and route all Internet
traffic via it instead of the analog modem? I'm guessing it should be a
couple changes (modules.conf, rc.local, sysconfig/static-routes)

2. How do I set the analog modem as a "fall back" in case a connection
can't be achieved via the cable modem?

3. What obvious things am I forgetting??


Here is ifconfig info for eth0 and ppp0.

eth0 Link encap:Ethernet HWaddr 000:xx:xx:xx:xx
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP
BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:6540 errors:0
dropped:0 overruns:0 frame:0 TX packets:6734 errors:0 dropped:0
overruns:12 carrier:0 collisions:0 txqueuelen:100 RX bytes:418254 (408.4
Kb) TX bytes:397668 (388.3 Kb) Interrupt:21 Base address:0x3000

ppp0 Link encap:Point-to-Point Protocol
inet addr:63.186.48.107 P-t-P:63.186.62.10 Mask:255.255.255.255 UP
POINTOPOINT RUNNING NOARP MULTICAST MTU:1524 Metric:1 RX packets:2128
errors:2 dropped:0 overruns:0 frame:0 TX packets:2512 errors:0 dropped:26
overruns:0 carrier:0 collisions:0 txqueuelen:3 RX bytes:1649845 (1.5 Mb)
TX bytes:195598 (191.0 Kb)

pt <(E-Mail Removed)> wrote in
news(E-Mail Removed) ndspring.com:

> I've got a working RHL 7.2 system. It's running as a server with
> DHCP, caching DNS, Samba, and iptables firewall for a couple Win
> boxes. I currently connect to Mindsproing via an analog modem as ppp0.
> The connection to my internal network is via the motherbd's built-in
> 10/100 (eth0). I'm going to switch ISPs to Comcastrate broadband,
> which means another NIC (3Com 3c509) to connect to whatever cable
> modem box they decide to rent to me. Layout prevents me from using USB
> from the cable modem to the server. I just installed the new NIC card,
> and the RHL Hardware Browser seems to detect it as a "3C509 100BaseTX
> (Boomerang)".
>
> I would _like_ (ahem) the option of keeping the analog modem attached
> for when (not if) I have problems with the cable modem connection.
>
> 1. What do I need to do to have the existing ethernet (82557/8/9)
> remain as eth0, and enable the second (3Com) card as eth1 and route
> all Internet traffic via it instead of the analog modem? I'm guessing
> it should be a couple changes (modules.conf, rc.local,
> sysconfig/static-routes)
>
> 2. How do I set the analog modem as a "fall back" in case a
> connection can't be achieved via the cable modem?
>
> 3. What obvious things am I forgetting??
>
>
> Here is ifconfig info for eth0 and ppp0.
>
> eth0 Link encap:Ethernet HWaddr 000:xx:xx:xx:xx
> inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0 UP
> BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:6540
> errors:0 dropped:0 overruns:0 frame:0 TX packets:6734 errors:0
> dropped:0 overruns:12 carrier:0 collisions:0 txqueuelen:100 RX
> bytes:418254 (408.4 Kb) TX bytes:397668 (388.3 Kb) Interrupt:21 Base
> address:0x3000
>
> ppp0 Link encap:Point-to-Point Protocol
> inet addr:63.186.48.107 P-t-P:63.186.62.10 Mask:255.255.255.255 UP
> POINTOPOINT RUNNING NOARP MULTICAST MTU:1524 Metric:1 RX
> packets:2128 errors:2 dropped:0 overruns:0 frame:0 TX packets:2512
> errors:0 dropped:26 overruns:0 carrier:0 collisions:0 txqueuelen:3 RX
> bytes:1649845 (1.5 Mb) TX bytes:195598 (191.0 Kb)
>

It doesn't have to mean another nic. If they provide you with a simple DSL
'modem' then you will need something else because your existing network is
plugged into your onboard nic. Some companies, especially if you advise
them up front that you have a home network, will provide you with a router
as well. The router can do NAT, forwarding, pinholes, etc, etc. If the
router is a one port then all you need is a hub, which you probably already
have. There are 4 port, 8 port, and other config routers.

Netopia and Linksys and probably many others provide the funtionality of
both in some models. You probably need to do some more technical consulting
with the Comcast engeneers to use this config. Otherwise you will have to
get another nic and make your linux box do all the routing, etc. What if
you make a mistake in the config? Your entire network is at risk. The
routers are a little easier to config.


Good luck making your choice.

Cheers,
Mark

On Fri, 04 Jul 2003 17:30:53 -0600, pt wrote:
> I've got a working RHL 7.2 system.

That RH 7.2 is getting long in the tooth. You may want to consider
upgrading to get the lastest security patches now that you are going
to be on cable.


> It's running as a server with DHCP,
> caching DNS, Samba, and iptables firewall for a couple Win boxes. I
> currently connect to Mindsproing via an analog modem as ppp0. The
> connection to my internal network is via the motherbd's built-in 10/100
> (eth0). I'm going to switch ISPs to Comcastrate broadband, which means
> another NIC (3Com 3c509) to connect to whatever cable modem box they
> decide to rent to me. Layout prevents me from using USB from the cable
> modem to the server. I just installed the new NIC card, and the RHL
> Hardware Browser seems to detect it as a "3C509 100BaseTX (Boomerang)".
>
> I would _like_ (ahem) the option of keeping the analog modem attached for
> when (not if) I have problems with the cable modem connection.
>
> 1. What do I need to do to have the existing ethernet (82557/8/9) remain
> as eth0, and enable the second (3Com) card as eth1 and route all Internet
> traffic via it instead of the analog modem?

To force eth1 as the default route I have

cat /etc/sysconfig/network
NETWORKING=yes
FORWARD_IPV4=yes
DHCP_HOSTNAME="x1-6-00-a0-cc-21-b8-9"
HOSTNAME=fw.home
DOMAINNAME=home
GATEWAY=12.209.206.1
GATEWAYDEV=eth1

You may have to read /etc/sysconfig/network-scripts/ifup
to see if RH 7.2 is different than the Mandrake I am running
for the use of the above variables.


> I'm guessing it should be a
> couple changes (modules.conf, rc.local, sysconfig/static-routes)

When I wanted to call work though the modem I setup a script like
/sbin/route del default
/bin/cp /etc/hosts.work/etc/hosts
/bin/cp /etc/resolv.conf_work /etc/resolv.conf

/usr/sbin/pppd /dev/modem 115200 \
crtscts defaultroute lock \
refuse-chap \
connect ${ppp_top}/chat-work

after dialup was closed I restored /etc/hosts and
/etc/resolv.conf_work with the cable values and restarted the network
with /etc/rc.d/init.d/network restart

>
> 2. How do I set the analog modem as a "fall back" in case a connection
> can't be achieved via the cable modem?

For fallback you could call a script from rc.local to test
the results of pinging your cable gateway. If it fails, call a script
to bring up the dialup.

>
> 3. What obvious things am I forgetting??

"R.Gunn" <(E-Mail Removed)> wrote in
news:bfr0o8$qbt$(E-Mail Removed):

> I find this of interest in particular as a current Windows user -
> trying to configure my RedHat9 machine to allow PPP access via modem -
> which will hopefully soon be replaced with ADSL if BT say I can get it
> after our exchange upgrade late August.
>
> Are you suggesting to use an ADSL router (presumably with built in
> modem) rather than let linux do the routing?

Actually, I would suggest that route AFTER you get the broadband. So, the
device will be a dsl modem/router. Not an analog modem/router.

Until then it is probably easier to let windows do ICS for the linux box
and let windows manage the modem. That is, of course, that it is only a
short time until the broadband connection get there...


<snip>



Mark

Thanks.

Yes, apoligies I was not clear, the router would be for ADSL not for
modem... I had been using IPCOP as a router/firewall to allow machines to
dialup but I really am trying to reduce the number of machines in use (and
their associated electric bills!)

Thats why I thought if I could get my RH file/web server to also route
traffic on ADSL it would be better (and cheaper) than also buying a router.

My RH box currently has 3 NICs and 1 internal modem.. only 1 NIC currently
running (eth0) - the other 2 I was indending (if I can figure it) to use for
(1) broadband modem port so Linux can do the routing and (2) for WLan if I
decide to go that route too - so I can block traffic (somehow) from the
wireless side.... I see IPCHAINS mentioned a lot so will be researching
that... but need to wait until > 20 August to see if I can get ADSL yet or
not!!

I looked at ICS once but it wanted to force an IP adress change so I turned
it off again... I use a 10.0.0. series not a 192.168.0. as ICS wanted.

Thanks
Richard


"Mark Taylor" <(E-Mail Removed)> wrote in message
news:Xns93C34AE73321Bmaintainersetifaqorg@216.65.9 8.9...
> "R.Gunn" <(E-Mail Removed)> wrote in
> news:bfr0o8$qbt$(E-Mail Removed):
>
> > I find this of interest in particular as a current Windows user -
> > trying to configure my RedHat9 machine to allow PPP access via modem -
> > which will hopefully soon be replaced with ADSL if BT say I can get it
> > after our exchange upgrade late August.
> >
> > Are you suggesting to use an ADSL router (presumably with built in
> > modem) rather than let linux do the routing?
>
> Actually, I would suggest that route AFTER you get the broadband. So, the
> device will be a dsl modem/router. Not an analog modem/router.
>
> Until then it is probably easier to let windows do ICS for the linux box
> and let windows manage the modem. That is, of course, that it is only a
> short time until the broadband connection get there...
>
>
> <snip>
>
>
>
> Mark
>

"R.Gunn" <(E-Mail Removed)> wrote in message
news:bfrkde$4ct$(E-Mail Removed)...
> Thanks.
>
> Yes, apoligies I was not clear, the router would be for ADSL not for
> modem... I had been using IPCOP as a router/firewall to allow machines to
> dialup but I really am trying to reduce the number of machines in use
(and
> their associated electric bills!)
>
> Thats why I thought if I could get my RH file/web server to also route
> traffic on ADSL it would be better (and cheaper) than also buying a
router.

If price is an issue I just got a dabs value (conexant) pci adsl modem
working in my gateway - 25 quid + p&p.

>
> My RH box currently has 3 NICs and 1 internal modem.. only 1 NIC
currently
> running (eth0) - the other 2 I was indending (if I can figure it) to use
for
> (1) broadband modem port so Linux can do the routing and (2) for WLan if
I
> decide to go that route too - so I can block traffic (somehow) from the
> wireless side.... I see IPCHAINS mentioned a lot so will be researching
> that... but need to wait until > 20 August to see if I can get ADSL yet
or
> not!!

Iptables is what you would need - if you are running a recent kernel.

Advanced routing is explained in the howto at www.lartc.org .

Andy.

> If price is an issue I just got a dabs value (conexant) pci adsl modem
> working in my gateway - 25 quid + p&p.

Sounds OK... Is that running on Linux?

I know its a relative word, but, how 'simple' is it to get routing
running.... securely.

My requirement is for ICQ/MSM etc. to still function from my main PC and
others on the LAN (via whatever method I use of connecting to ADSL), and to
be able to setup incoming port forwarding so I can take a port from the ADSL
gateway and forward it to (another) machine on the network to be hosted.

Is this sort of functionality possible for a complete newcomer to establish
with RH9 "out of the box"?!

Richard

R.Gunn wrote:

> I know its a relative word, but, how 'simple' is it to get routing
> running.... securely.

This depends on your familiarity with Linux. I am familiar with working
in a Linux/*nix environment as a normal user (in fact, my whole research
programming is in Unix and Linux). But I am just now becoming familiar
with the nuts and bolts of maintenance of a Linux system and networking
(since I got a comp and installed Linux at home .... no professional adm
help here as we get in our Univ !! )

BTW, I am running Redhat 8.0 kernel 2.4.20-19.8.



>
> My requirement is for ICQ/MSM etc. to still function from my main PC and
> others on the LAN (via whatever method I use of connecting to ADSL), and to
> be able to setup incoming port forwarding so I can take a port from the ADSL
> gateway and forward it to (another) machine on the network to be hosted.
>
> Is this sort of functionality possible for a complete newcomer to establish
> with RH9 "out of the box"?!


Yes, it is.

I have just got my local network working. I am connected to the internet
through ADSL at ppp0. The ADSL device is connected to my eth0. My eth1
is connected to my internal network (actually, just one computer in my
network THe other computer is connected via a switch. So:
.---------------------------------.
ppp0---->eth0---Linux RH8.0------>eth1 | <---Linux box
'--------------------------|------'
|
Switch
|
.------.-------.---------.-------.
| | | |
Wind95 free free free


My internal network: I have set it up aa 192.168.0.0/24

I also have a firewall script that is run at boot time (which loads
necessary modules and sets up forwarding). Currently, I have
successfully run the IE browser, downloaded Cygwin stuff, run mIRC and
yahoomessenger in Win95 machine. Haven't tried ICQ (I don't use it
actually).


To do this, all that was necessary was install a second nic in my Linux
box, and enable masquarading (done by the firewall script). The security
issue is handled, of course, by the same firewall script. Security is
*_very important_*. This sounds simple, but I had a tough time
installing the second nic, *only* because I used the
SYstemSettings->Network GUI of RH8.0. It changed some files permissions
by itself and I couldn't browse the net anymore. ONce I got familiar
with the various files, everything else was relatively easy. To see the
difficulties I had, and how they were solved, while installing the nics,
see the thread:
"peculiar problem: ping works, but cannot browse. Need help of network
gurus." in this newsgroup.

If you want, I can help you, as much as I can, with any of the above
setup steps.

But I notice you say that you already just use the Network GUI. Since
you are not familiar with Linux files (configuration and options),
perhaps I can help you with this method too. Just use the GUI, and I
will tell you what potential permission problems to look out for.


Good luck,
->HS


--
---------------------- X ----------------------
Remove all underscores from my email address to get the correct one.
Apologies for the inconvenience, but this is to reduce spam.

"R.Gunn" <(E-Mail Removed)> wrote in message
news:bg30dq$mtq$(E-Mail Removed)...
> > If price is an issue I just got a dabs value (conexant) pci adsl modem
> > working in my gateway - 25 quid + p&p.
>
> Sounds OK... Is that running on Linux?

Yes - on a 2.4.21, it requires a binary driver and some patching/compiling.

>
> I know its a relative word, but, how 'simple' is it to get routing
> running.... securely.
>
> My requirement is for ICQ/MSM etc. to still function from my main PC and
> others on the LAN (via whatever method I use of connecting to ADSL), and
to
> be able to setup incoming port forwarding so I can take a port from the
ADSL
> gateway and forward it to (another) machine on the network to be hosted.
>
> Is this sort of functionality possible for a complete newcomer to
establish
> with RH9 "out of the box"?!

I suppose so - but then I haven't done it, don't use redhat & only do basic
stuff at the moment :-)

Andy.

Hi H...

> This depends on your familiarity with Linux. I am familiar with working
> in a Linux/*nix environment as a normal user (in fact, my whole research
> programming is in Unix and Linux). But I am just now becoming familiar
> with the nuts and bolts of maintenance of a Linux system and networking
> (since I got a comp and installed Linux at home .... no professional adm
> help here as we get in our Univ !! )
>
> BTW, I am running Redhat 8.0 kernel 2.4.20-19.8.

I am pretty much completely new to Linux... I am slowly learning it all...
and trying to do without the GUI where possible - I tend to use it to see
how it hangs together but ultimately would rather learn the use of command
prompt and the art of Vi rather than dragging a mouse around.

> I have just got my local network working. I am connected to the internet
> through ADSL at ppp0. The ADSL device is connected to my eth0. My eth1
> is connected to my internal network (actually, just one computer in my
> network THe other computer is connected via a switch. So:

Thats the way I was heading... except I have also added a 3rd NIC to act as
either a DMZ (less likely) or for a second network for the neighbours to
connect to so they can use the Internet connection but not get to the other
machines on the rest of the network.... maybe!

> My internal network: I have set it up aa 192.168.0.0/24

Could you point me to some information/explanation on the /24 you mention
above. I have seen variants of this used but never seen what it actually
means!

> I also have a firewall script that is run at boot time (which loads
> necessary modules and sets up forwarding). Currently, I have
> successfully run the IE browser, downloaded Cygwin stuff, run mIRC and
> yahoomessenger in Win95 machine. Haven't tried ICQ (I don't use it
> actually).

Where can I find the script? I actually use Trillian for messaging - it has
the capability of IRC, AIM, Y!, MSM, ICQ all in 1 application which is handy
(I use the latter 3)

> *_very important_*. This sounds simple, but I had a tough time
> installing the second nic, *only* because I used the
> SYstemSettings->Network GUI of RH8.0. It changed some files permissions
> by itself and I couldn't browse the net anymore. ONce I got familiar
> with the various files, everything else was relatively easy. To see the
> difficulties I had, and how they were solved, while installing the nics,
> see the thread:
> "peculiar problem: ping works, but cannot browse. Need help of network
> gurus." in this newsgroup.

That's really useful - another reason for me trying to stick by the command
prompt then!! ;o)

> If you want, I can help you, as much as I can, with any of the above
> setup steps.

Thanks for the offer of help - I may well take you up on that once I get a
bit more involved (and have ADSL into the building to play with)

> But I notice you say that you already just use the Network GUI. Since
> you are not familiar with Linux files (configuration and options),
> perhaps I can help you with this method too. Just use the GUI, and I
> will tell you what potential permission problems to look out for.

As I metnioned earlier, I would rather learn the command prompt way of doing
things. As it stands only "eth0" (my LAN NIC) has been configured. eth1
and eth2 remain "inactive" but have been detected by the RH9 installation
process.

> Good luck,
Thank you! And thanks again for the advice and offer of help.

Richard