Hi!
I am in trouble because of my SuSE firewall2 settings.
I have a firewall with six network adapters. One of them points to the
DMZ, one of them points to the internal network and the others point to
untrusted external worlds.
There is a web server and a mail server running on the DMZ. Everybody
can access the web server and the mail server (from the external world
or from the internal network).
The DMZ has a private IP address.
Everybody use the proper IP address of the firewall to access the
services on the DMZ server. It works fine.
I wanted to use the same method for the internal network. And there is a
strange behaviour. I know thta the firewall does not route between the
DMZ and the internal net by default (bot he the DMZ and the internal net
are masqueraded) so I used the FW_FORWARD optiona to access mail and web
services from internal on DMZ. The IP address of the DMZ server is
192.168.122.2 and the internal net is 192.168.120.0/24 where
192.168.120.1 point to the interface of the firewall.
I tried the 192.168.120.1 in my WEB browser (from the internal network)
and it did not work. After that I tried the 192.168.122.2 and it worked.
But why? I think I must use the IP address of the firewall to access
services behind the firewall with FW_FORWARD and FW_FORWARD_MASQ
options. Can anobody explain how it works? I already checked the
relevant pdf documentations but they did not help.
If I try to access theWEB server from the internet and I specify the IP
address of the firewall, then it works fine. But it does not work from
the internal network on the same way.
And there is a second more serious problem. OK, I use the 192.168.122.2
from internal network to access web and mail.
I tried to check my e-mails with IMAP from the internal network. It
worked but there were a long delay.
The firewall log showed:
Jun 18 00:28:49 (none) kernel: SuSE-FW-ACCEPT-TRUST IN=eth0 OUT=eth1
SRC=192.168.120.30 DST=192.168.122.2 LEN=44 TOS=0x00 PREC=0x00 TTL=127
ID=19187 DF PROTO=TCP SPT=4177 DPT=143 WINDOW=44032 RES=0x00 SYN URGP=0
OPT (020405B4)
Jun 18 00:28:49 (none) kernel: SuSE-FW-DROP-DEFAULT IN=eth1 OUT=eth0
SRC=192.168.122.2 DST=192.168.120.30 LEN=60 TOS=0x00 PREC=0x00 TTL=63
ID=57671 DF PROTO=TCP SPT=40188 DPT=113 WINDOW=5840 RES=0x00 SYN URGP=0
OPT (020405B40402080A034647B10000000001030300)
Jun 18 00:28:52 (none) kernel: SuSE-FW-DROP-DEFAULT IN=eth1 OUT=eth0
SRC=192.168.122.2 DST=192.168.120.30 LEN=60 TOS=0x00 PREC=0x00 TTL=63
ID=57672 DF PROTO=TCP SPT=40188 DPT=113 WINDOW=5840 RES=0x00 SYN URGP=0
OPT (020405B40402080A034648DD0000000001030300)
Jun 18 00:28:58 (none) kernel: SuSE-FW-DROP-DEFAULT IN=eth1 OUT=eth0
SRC=192.168.122.2 DST=192.168.120.30 LEN=60 TOS=0x00 PREC=0x00 TTL=63
ID=57673 DF PROTO=TCP SPT=40188 DPT=113 WINDOW=5840 RES=0x00 SYN URGP=0
OPT (020405B40402080A03464B350000000001030300)
I think the SuSE-FW-DROP-DEFAULT cause the delay.
Any help would be apprecieted.
Best regards,
Sandor Toth
Ps: I use SuSE 8.2 Prof
My routing table is:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
10.12.2.64 0.0.0.0 255.255.255.248 U 0 0 0
eth2
192.168.102.0 192.168.121.254 255.255.255.0 UG 0 0 0
eth4
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0
eth3
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth5
192.168.14.0 192.168.121.254 255.255.255.0 UG 0 0 0
eth4
192.168.120.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
192.168.121.0 0.0.0.0 255.255.255.0 U 0 0 0
eth4
192.168.106.0 192.168.121.254 255.255.255.0 UG 0 0 0
eth4
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0
eth1
0.0.0.0 10.12.2.65 0.0.0.0 UG 0 0 0
eth2
My SuSE firewall settings are:
FW_QUICKMODE="no"
FW_DEV_EXT="eth2 eth3 eth4 eth5 ppp0"
FW_DEV_INT="eth0"
FW_DEV_DMZ="eth1"
FW_ROUTE="yes"
FW_MASQUERADE="yes"
FW_MASQ_DEV="$FW_DEV_EXT"
FW_MASQ_NETS="192.168.120.0/24 192.168.122.0/24"
FW_PROTECT_FROM_INTERNAL="yes"
FW_AUTOPROTECT_SERVICES="yes"
FW_SERVICES_EXT_TCP=""
FW_SERVICES_EXT_UDP=""
FW_SERVICES_EXT_IP=""
FW_SERVICES_DMZ_TCP="domain"
FW_SERVICES_DMZ_UDP="domain"
FW_SERVICES_DMZ_IP="tcp"
FW_SERVICES_INT_TCP="domain ssh 224"
FW_SERVICES_INT_UDP="domain"
FW_SERVICES_INT_IP="tcp"
FW_SERVICES_QUICK_TCP=""
FW_SERVICES_QUICK_UDP=""
FW_SERVICES_QUICK_IP=""
FW_TRUSTED_NETS=""
FW_ALLOW_INCOMING_HIGHPORTS_TCP="yes"
FW_ALLOW_INCOMING_HIGHPORTS_UDP="yes"
FW_SERVICE_AUTODETECT="yes"
FW_SERVICE_DNS="yes"
FW_SERVICE_DHCLIENT="no"
FW_SERVICE_DHCPD="no"
FW_SERVICE_SQUID="no"
FW_SERVICE_SAMBA="no"
FW_FORWARD="192.168.120.0/24,192.168.122.2,tcp,23 \
192.168.120.0/24,192.168.122.2,tcp,80 \
192.168.120.0/24,192.168.122.2,tcp,139 \
192.168.120.0/24,192.168.122.2,tcp,25 \
192.168.120.0/24,192.168.122.2,tcp,110 \
192.168.120.0/24,192.168.122.2,tcp,143"
FW_FORWARD_MASQ="\
192.168.14.0/24,192.168.120.19,tcp,3389 \
192.168.14.0/24,192.168.120.18,tcp,7781 \
192.168.14.0/24,192.168.120.18,tcp,445 \
192.168.14.0/24,192.168.122.2,tcp,23 \
192.168.14.0/24,192.168.120.18,tcp,1522 \
192.168.14.0/24,192.168.120.13,tcp,80 \
192.168.14.0/24,192.168.120.30,tcp,6000 \
192.168.14.0/24,192.168.120.18,tcp,139 \
0/0,192.168.122.2,tcp,25 \
0/0,192.168.122.2,tcp,110 \
0/0,192.168.122.2,tcp,143 \
0/0,192.168.122.2,tcp,80 \
192.168.102.101,192.168.120.30,tcp,6000 \
192.168.102.102,192.168.120.30,tcp,6000" # Beware to use this!
FW_REDIRECT=""
FW_LOG_DROP_CRIT="yes"
FW_LOG_DROP_ALL="yes"
FW_LOG_ACCEPT_CRIT="yes"
FW_LOG_ACCEPT_ALL="no"
FW_LOG="--log-level warning --log-tcp-options --log-ip-option
--log-prefix SuSE-FW"
FW_KERNEL_SECURITY="yes"
FW_STOP_KEEP_ROUTING_STATE="no"
FW_ALLOW_PING_FW="no"
FW_ALLOW_PING_DMZ="no"
FW_ALLOW_PING_EXT="no"
FW_ALLOW_FW_TRACEROUTE="no"
FW_ALLOW_FW_SOURCEQUENCH="no"
FW_ALLOW_FW_BROADCAST="no"
FW_IGNORE_FW_BROADCAST="yes"
FW_ALLOW_CLASS_ROUTING="no"
FW_CUSTOMRULES=""
FW_REJECT="no"
FW_HTB_TUNE_DEV=""