-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Wed, Mar 29, 2017 at 08:51:58AM -0700, Mike McClain wrote: > On Tue, Mar 28, 2017 at 10:14:50PM -0400, Dan Ritter wrote: > > On Tue, Mar 28, 2017 at 04:46:02PM -0700, Mike McClain wrote: > <snip> > > > The situation is this: > > > > > > phone eth0 eth1 > > > AT&T-------| |--------| |--------| |-------| | > > > AT&T modem/ Linux my Win2K > > > router box router box
[...] > Here are the statements from the firewall on the Linux box > that deal with the LAN: > > INET=eth0; > LAN=eth1; > S40='192.168.1.3'; # static IP of Win2K box > > # for masq allow forwarding > fwd=1; > echo $fwd > /proc/sys/net/ipv4/ip_forward > echo $fwd > /proc/sys/net/ipv4/conf/all/forwarding > echo $fwd > /proc/sys/net/ipv4/conf/default/forwarding > echo $fwd > /proc/sys/net/ipv4/conf/lo/forwarding > echo $fwd > /proc/sys/net/ipv4/conf/eth0/forwarding > echo $fwd > /proc/sys/net/ipv4/conf/eth1/forwarding > > iptables -A INPUT -i $LAN -j ACCEPT > iptables -A OUTPUT -f -d $S40 -j DROP The above looks suspect: packets leaving your Linux box towards your Windows box are dropped? Perhaps I'm missing something. > iptables -A FORWARD -i $LAN -j ACCEPT > iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT > iptables -t nat -A POSTROUTING -o $INET -j MASQUERADE > > eth0 up, eth1 down > root@/deb73:~> route -n > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use Iface > 0.0.0.0 99.188.244.1 0.0.0.0 UG 0 0 0 eth0 > 99.188.244.0 0.0.0.0 255.255.252.0 U 0 0 0 eth0 OK. > eth0 up, eth1 up > root@/deb73:~> route -n > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use Iface > 0.0.0.0 99.188.244.1 0.0.0.0 UG 0 0 0 eth0 > 99.188.244.0 0.0.0.0 255.255.252.0 U 0 0 0 eth0 > 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 This looks sensible, too. > eth0 down, eth1 up > root@/deb73:~> route -n > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use Iface > 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 and this. Hmmm. The routing tables look sane to me. At the moment I have no explanation why the Linux box can't "see" the Internet while the net to the Windows box is up. Can you ping the AT&T router? When the Windows net is up/is down? regards - -- tomás -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAljcDbcACgkQBcgs9XrR2kaEBQCeLofOgV12Z6nMGqsyp6uFA3Rm Oi0AniEW1OQHJalIm2tvQXA/3OyVb1ij =jxTG -----END PGP SIGNATURE-----
