Re: Wan/Lan problem
- Date: Tue, 28 Mar 2017 22:14:50 -0400
- From: Dan Ritter <dsr@xxxxxxxxxxxxxxxx>
- Subject: Re: Wan/Lan problem
On Tue, Mar 28, 2017 at 04:46:02PM -0700, Mike McClain wrote:
> I have a WAN/LAN challenge I'm hoping for help with.
> I'm runniing Debian 7.11 on a Pentium 3 with 250MB ram.
> mike@/deb7:~> uname -a
> Linux playground 3.2.0-4-686-pae #1 SMP Debian 3.2.84-2 i686 GNU/Linux
> The situation is this:
> phone eth0 eth1
> AT&T-------| |--------| |--------| |-------| |
> AT&T modem/ Linux my Win2K
> router box router box
> When eth0 is up and eth1 down,
> the Linux box can access the web.
> 'ping ATTrouter' works.
> When eth0 is up and eth1 up,
> the Linux box can not access the web.
> the Win2K box can access the web.
> the Linux box can not access the Win2K shares.
> 'ping ATTrouter' fails.
> 'ping -Ieth0 ATTrouter' works.
> When eth0 is down and eth1 up,
> the Linux box can access the Win2K shares.
> When eth0 is down and eth1 down,
> it's quiet.
> The ATT router is set to 'Pass Through' giving the Linux box the ATT
> router's IP address.
> The Linux box is set to use DHCP.
> This might explain why I loose the LAN connection when eth0 up.
> Why can the Linux box not see the web while the Win2K box can?
> I've not found or at least recognized the problem in the HowTo's.
> Pointer's or suggestions?
> # The loopback network interface
> auto lo
> iface lo inet loopback
> # The primary network interface
> allow-hotplug eth1
> # eth0 = onboard eth port
> iface eth0 inet dhcp
> # eth1 = 3Com PCI 3c905C card
> iface eth1 inet static
> address 192.168.1.2
> netmask 255.255.255.0
> network 192.168.1.0
> broadcast 192.168.1.255
> # dns-* options are implemented by the resolvconf package, if installed
> dns-nameservers 126.96.36.199 188.8.131.52
You're going to end up discovering that this is a problem in IP
assignment, routing, forwarding, or something very similar.
What masquerading are you doing? What IP forwarding? What
routing entries are present?