Hi, looks like the packets are not hitting the POSTROUTING-Hook. Are you sure that you have forwarding enabled in your kernel? Check /proc/sys/net/ipv4/ip_forward Or an iptables rule in the forwarding-chain? Regards, Christoph On Fri 5 February 2010 wrote Dan Daugherty: > I had to make some changes to the ultimate destination since the > machine I am trying to get to didn't have tcpdump and getting it for > solaris isn't worth it to me. Since I know this is an iptables issue, > I'm good with using a different destination to test and then change it > in production. > > Dictionary: > err.sfa.com is the machine from which I am testing. ip of 6.149 > sethra is the router. ip of 1.205 > vlad is the destination machine. ip of 1.206 > > > Commands used on sethra: > iptables -F > iptables -F -t nat > iptables -t nat -A PREROUTING -p tcp -i eth0 --dport 1521 -j LOG > --log-prefix '**LOG PRE** ' > iptables -t nat -A POSTROUTING -o eth0 -p tcp -j LOG --log-prefix > '**LOG POST** ' > > iptables -t nat -A PREROUTING -p tcp --dport 1521 -i eth0 -j DNAT --to > 10.117.1.206:1521 > iptables -t nat -A POSTROUTING -o eth0 -d 10.117.1.206 -p tcp --dport > 1521 -j SNAT --to-source 10.117.1.205 > > err:~ dan$ telnet 10.117.1.205 1521 > Trying 10.117.1.205... > telnet: connect to address 10.117.1.205: Operation timed out > telnet: Unable to connect to remote host > > packet counts > [root@sethra ~]# iptables -t nat -nvL > Chain PREROUTING (policy ACCEPT 35405 packets, 42M bytes) > pkts bytes target prot opt in out source > destination > 22 1152 LOG tcp -- eth0 * 0.0.0.0/0 > 0.0.0.0/0 tcp dpt:1521 LOG flags 0 level 4 prefix `**LOG > PRE** ' > 22 1152 DNAT tcp -- eth0 * 0.0.0.0/0 > 0.0.0.0/0 tcp dpt:1521 to:10.117.1.206:1521 > > Chain POSTROUTING (policy ACCEPT 428 packets, 39754 bytes) > pkts bytes target prot opt in out source > destination > 0 0 LOG tcp -- * eth0 0.0.0.0/0 > 0.0.0.0/0 LOG flags 0 level 4 prefix `**LOG POST** ' > 0 0 SNAT tcp -- * eth0 0.0.0.0/0 > 10.117.1.206 tcp dpt:1521 to:10.117.1.205 > > Chain OUTPUT (policy ACCEPT 471 packets, 48328 bytes) > pkts bytes target prot opt in out source > destination > > > Kernel logs: > Feb 5 14:01:27 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=64 TOS=0x10 PREC=0x00 TTL=64 ID=13244 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:28 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=64 TOS=0x10 PREC=0x00 TTL=64 ID=1431 DF PROTO=TCP > SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:29 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=64 TOS=0x10 PREC=0x00 TTL=64 ID=21407 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:30 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=44931 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:31 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=17401 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:32 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=23430 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:34 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=34207 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:38 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=7366 DF PROTO=TCP > SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:01:46 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=36068 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:02:02 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=32933 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > Feb 5 14:02:34 sethra kernel: **LOG PRE** IN=eth0 OUT= > MAC=00:26:b9:3f:89:f9:00:17:f2:c8:24:8a:08:00 SRC=10.117.6.149 > DST=10.117.1.205 LEN=48 TOS=0x10 PREC=0x00 TTL=64 ID=32389 DF > PROTO=TCP SPT=62981 DPT=1521 WINDOW=65535 RES=0x00 SYN URGP=0 > > TPCDUMP sethra > [root@sethra ~]# tcpdump -i eth0 'port 1521' > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode > listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes > 14:01:27.126210 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,nop,wscale > 3,nop,nop,timestamp 635091437 0,sackOK,eol> > 14:01:28.107814 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,nop,wscale > 3,nop,nop,timestamp 635091446 0,sackOK,eol> > 14:01:29.108654 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,nop,wscale > 3,nop,nop,timestamp 635091456 0,sackOK,eol> > 14:01:30.109676 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > 14:01:31.110723 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > 14:01:32.111917 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > 14:01:34.113682 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > 14:01:38.117485 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > 14:01:46.125289 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > 14:02:02.139805 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > 14:02:34.169506 IP err.sfa.com.62981 > sethra.sfa.com.ncube-lm: S > 3593594566:3593594566(0) win 65535 <mss 1460,sackOK,eol> > > 11 packets captured > 11 packets received by filter > 0 packets dropped by kernel > > TCPDUMP vlad > [root@vlad ~]# tcpdump -i eth0 'port 1521' > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode > listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes > -- > To unsubscribe from this list: send the line "unsubscribe netfilter" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Christoph Paasch Alcatel-Lucent IP Development www.rollerbulls.be -- -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
