altcnc
2002-Dec-19 08:58 UTC
[Shorewall-users] Shorewall works behind firewall, but not as firewall...
I''m attempting to setup Shorewall on a box that is to replace my current firewall/router/etc... I currently have a two-interface setup like the one described in the HOWTO, and am configuring the Shorewall box as the same. I installed Shorewall on the box, behind my current firewall on a private network (10/8 on eth0), and placed a switch and another computer behind the Shorewall box (192.168.0/24 on eth1). I was very please with the setup, and it appeared to work wonderfully right away. The windows computer behind the shorewall box got it''s dhcp lease and was able to access the internet and the shorewall box, the shorewall box was able to access the windows computer and the internet, looked great. Next, I brought down my network, and moved the Shorewall box to replace my current firewall (just like the two-interface HOWTO is laid out). When I brought the network back up, the Shorewall box correctly got it''s public IP address on eth0, however, now the all2all chain is blocking traffic from the computers behind the firewall to the internet and from the firewall to the internet (enabled in the policy file). I can ping, ssh, etc between the firewall and local network, but cannot ping, ssh, http, past the Shorewall box to the internet. I can''t understand why it would work behind my original firewall, but not in place of it. (yes the original firewall is completely off the network, I''ve restarted my cable modem, all computers on the network, shorewall, ifcfg-eth0 and ifcfg-eth1 were correctly rewritten and restarted to match the new configuration. I''ve commented out 10/8 and 192.168.0/24 in the rfc1918) What''s going wrong and what information can I provide to help determine the cause... RedHat 8.0 iptables 1.2.6a kernel 2.4.18-8.0smp /etc/shorewall/masq #INTERFACE SUBNET ADDRESS eth0 eth1 /etc/shorewall/policy #SOURCE DEST POLICY LOG LEVEL LIMIT:BURST loc net ACCEPT # # If you want open access to the internet from your firewall, uncomment the # following line fw net ACCEPT net all DROP info all all REJECT info Typical log entries: Dec 18 23:37:24 junzabid2 kernel: Shorewall:all2all:REJECT:IN=eth1 OUT=eth1 SRC=10.0.0.2 DST=128.95.120.1 LEN=62 TOS=0x00 PREC=0x00 TTL=127 ID=6472 PROTO=UDP SPT=2090 DPT=53 LEN=42 Dec 18 23:32:45 junzabid2 kernel: Shorewall:all2all:REJECT:IN= OUT=eth1 SRC=10.0.0.1 DST=204.127.198.4 LEN=71 TOS=0x00 PRE C=0x00 TTL=64 ID=36058 DF PROTO=UDP SPT=1024 DPT=53 LEN=51 (hmmm ok, now I notice: why are these entering and leaving eth1?) Thanks...
Tom Eastep
2002-Dec-19 15:15 UTC
[Shorewall-users] Shorewall works behind firewall, but not as firewall...
--On Thursday, December 19, 2002 12:58:29 AM -0800 altcnc <altcnc@hotmail.com> wrote:> (hmmm ok, now I notice: why are these entering and leaving eth1?) >Check your routing table -Tom -- Tom Eastep \ Shorewall - iptables made easy Shoreline, \ http://shorewall.sf.net Washington USA \ teastep@shorewall.net
Tom Eastep
2002-Dec-19 15:39 UTC
[Shorewall-users] Shorewall works behind firewall, but not as firewall...
--On Thursday, December 19, 2002 12:58:29 AM -0800 altcnc <altcnc@hotmail.com> wrote:> Typical log entries: > Dec 18 23:37:24 junzabid2 kernel: Shorewall:all2all:REJECT:IN=eth1 > OUT=eth1 SRC=10.0.0.2 DST=128.95.120.1 LEN=62 TOS=0x00 PREC=0x00 TTL=127 > ID=6472 PROTO=UDP SPT=2090 DPT=53 LEN=42 > Dec 18 23:32:45 junzabid2 kernel: Shorewall:all2all:REJECT:IN= OUT=eth1 > SRC=10.0.0.1 DST=204.127.198.4 LEN=71 TOS=0x00 PRE C=0x00 TTL=64 ID=36058 > DF PROTO=UDP SPT=1024 DPT=53 LEN=51 > > (hmmm ok, now I notice: why are these entering and leaving eth1?) >This can also be caused by having both eth0 and eth1 connected to the same hub or switch. -Tom -- Tom Eastep \ Shorewall - iptables made easy Shoreline, \ http://shorewall.sf.net Washington USA \ teastep@shorewall.net