I have done absolutely what u have said.. I have rechecked the source port and destination and are the same.... The programme is a packet generator that creates bulk data. We use it to test oure network.... I have applied your commands but with a little changes iptables -nat -A PREROUTING -i eth1 -d 143.233.222.77 -p udp --destination-port 22453 -j DNAT --to-destination 10.2.4.1:22453 My problem is that still i cant see any packages in the eth0 interface.. What know what else should i do now --- "John A. Sullivan III" <jsullivan@xxxxxxxxxxxxxxxxxxx> wrote: > It sounds like you really need to learn the basics. > I would suggest you > go through the links I mentioned below. What > exactly do you want to do? > > It sounds like you want traffic coming in from > 143.233.222.253 on tcp > destination port 22453 (are you sure this is the > destination port and > not the source port?????) on the laptop interface > eth1 with IP address > 143.233.222.77 to be sent to 10.2.4.1 on the eth0 > interface. I am > assuming that 143.233.222.77 and 143.233.222.253 are > on the same > network, i.e., the subnet mask is 255.255.255.0 or > less. I also > assuming that you have enabled forwarding as you > said you did. > > Then you would do something like: > > iptables -F > iptables -t nat -F > iptables -P FORWARD DROP > iptables -t nat -P ACCEPT > iptables -t nat -A PREROUTING -i eth1 -d > 143.233.222.77 --dport 22453 -j > DNAT --to-destination 10.2.4.1:22453 > iptables -A FORWARD -m state --state > ESTABLISHED,RELATED -j ACCEPT > iptables -A FORWARD -s 143.233.222.253 -d 10.2.4.1 > -p 6 --dport 22453 -j > ACCEPT > > I have a sneaking suspicion that 22453 is not the > destination port. > What service is 10.2.4.1 providing to > 143.233.222.253? > > I'm afraid I'm running out of time today. I > probably cannot help much > more. I'm sure someone else can jump in. Take care > - John > > On Tue, 2005-09-27 at 08:40 -0700, Alaios wrote: > > My complete rule set??? Hm... there is nothing > like > > that... I work to a solution for 4-5 hours and > still > > havent finded any iptable rule to work.. in my pc > i > > dont have any ip rules loaded at all nor a > firewall > > applied.. I just want to do only this to work.. Do > u > > have anything else in mind plz? > > > > --- "John A. Sullivan III" > > <jsullivan@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > I made some assumptions about other rules you > would > > > have had in place. > > > I believe someone else posted a much more > thorough > > > answer. Did you > > > create an ESTABLISHED,RELATED rule as that other > > > post suggested? > > > > > > Would you mind posting your complete rule set > (with > > > any sensitive > > > information edited, of course)? - John > > > > > > On Tue, 2005-09-27 at 08:30 -0700, Alaios wrote: > > > > Thx for your quick reply..... i have just > tested > > > but > > > > it didnt work... I think that i cant explain > what > > > i > > > > need or i am doing sth wrong.. > > > > i have enabled the packets loging > > > > so executing dmesg prints the following > > > > IN=eth1 OUT= MAC=(the mac addresses) > > > > As u can see the OUT is null which means thats > > > perhaps > > > > the problem... What do u have in mind? > > > > > > > > --- "John A. Sullivan III" > > > > <jsullivan@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > > On Tue, 2005-09-27 at 11:14 -0400, John A. > > > Sullivan > > > > > III wrote: > > > > > > On Tue, 2005-09-27 at 07:57 -0700, Alaios > > > wrote: > > > > > > > Hi plz take a look at the following > example > > > > > > > > > > > > > > The laptop has 2 ethernet interfaces > > > > > > > To eth1 comes traffic from src > > > 143.233.222.253 > > > > > > > The eth0 has ip address 10.2.4.2 and it > is > > > > > connected > > > > > > > back to back with eth1 of other pc with > ip > > > > > address > > > > > > > 10.2.4.1 > > > > > > > I want to forward the traffic with src > > > > > 143.233.222.253 > > > > > > > to the 10.2.4.1 pc and if it works i > will > > > redo > > > > > this > > > > > > > for a second pc so as to l send the > traffic > > > to a > > > > > third > > > > > > > on. > > > > > > > Can u help me plz? > > > > > > > > > > > > > > I have tried this one > > > > > > > iptables -t nat -A PREROUTING -i eth1 -s > > > > > > > 143.233.222.253 -j DNAT --to-destination > > > > > 10.2.4.1 > > > > > > > i have also set the > > > > > > > /proc/sys/net/ipv4/ip_forward to 1 > > > > > > > but still i cant see any trafiic to eth0 > > > > > interface (ip > > > > > > > 10.2.4.2) > > > > > > > > > > > > > > > > > > > > > I have also tested this one > > > > > > > iptables -t nat -A PREROUTING -p tcp -d > > > > > 143.233.222.77 > > > > > > > (laptop eth1 card) --dport 22453 (i have > > > cheched > > > > > dst > > > > > > > port with tcpdump) 00 -j DNAT > > > --to-destination > > > > > > > 10.2.4.1 > > > > > > > this still doesnt work > > > > > > > Every time i try to apply a new rule i > use > > > first > > > > > > > the iptables -F > > > > > > > iptables -t nat -F command > > > > > > <snip> > > > > > > > > > > > > I'm a little confused about what you are > > > doing. I > > > > > would normally refer > > > > > > you to Oskar Andreasson's excellent > tutorial > > > at > > > > > > > > > > > > > > > > > > > > > http://iptables-tutorial.frozentux.net/iptables-tutorial.html > > > > > or the > > > > > > training slides on the ISCS web site > > > > > (http://iscs.sourceforge.net) but, > > > > > > since it appears that you have an > emergency, > > > here > > > > > goes: > > > > > > > > > > > > First, if the source is 143.233.222.253, > you > > > would > > > > > not want to DNAT it. > > > > > > DNAT changes the destination. Thus, your > > > second > > > > > attempt is the correct > > > > > > one. You might want to lock the > destination > > > port > > > > > - it's not likely to > > > > > > be a problem but, if it ever is, it will > be > > > one of > > > > > those really hard to > > > > > > diagnose, sporadic problems: > > > > > > -j DNAT --to-destination 10.2.4.1:22453 > > > > > > > > > > > > Second, this only takes care of the > > > addressing. > > > > > You must still allow > > > > > > the traffic in the FORWARD chain of the > filter > > > > > table, e.g., > > > > > > > > > > > > iptables -A FORWARD -d 10.2.4.1 -p 6 > --dport > > > 22453 > > > > > -j ACCEPT > > > > > > > > > > > > Hope this helps - John > > > > > > > > > > Oh, yes, you wanted to restrict the source > > > address. > > > > > Add that to your > > > > > filter table rule: > > > > > iptables -A FORWARD -s 143.233.222.253 -d > > > 10.2.4.1 > > > > > -p 6 --dport 22453 -j > > > > > ACCEPT > > > > > -- > > > > > John A. Sullivan III > > > > > Open Source Development Corporation > > > > > +1 207-985-7880 > > > > > jsullivan@xxxxxxxxxxxxxxxxxxx > > > > > > > > > > If you would like to participate in the > > > development > > > > > of an open source > > > > > enterprise class network security management > > > system, > > > > > please visit > > > > > http://iscs.sourceforge.net > > > > > > > > > > > > > > > > > > > __________________________________________________ > > > > Do You Yahoo!? > > > > Tired of spam? Yahoo! Mail has the best spam > > > protection around > > > > http://mail.yahoo.com > > > -- > > > John A. Sullivan III > > > Open Source Development Corporation > > > +1 207-985-7880 > > > jsullivan@xxxxxxxxxxxxxxxxxxx > > > > > > Financially sustainable open source development > > > http://www.opensourcedevel.com > > > > > > > > > > __________________________________________________ > > Do You Yahoo!? > > Tired of spam? Yahoo! Mail has the best spam > protection around > > http://mail.yahoo.com > -- > John A. Sullivan III > Open Source Development Corporation > +1 207-985-7880 > jsullivan@xxxxxxxxxxxxxxxxxxx > > Financially sustainable open source development > http://www.opensourcedevel.com > > __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com
