> The advice to add: > net.ipv4.ip_forward = 1 > to /etc/sysctl.conf only takes effect after the next > reboot. If you want to change this on the fly you can: > echo 1 > /proc/sys/net/ipv4/ip_forward > [root@localhost ~]# cat /etc/sysctl.conf # Kernel sysctl configuration file for Red Hat Linux # # For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and # sysctl.conf(5) for more details. # Controls IP packet forwarding net.ipv4.ip_forward = 1 # Controls source route verification net.ipv4.conf.default.rp_filter = 1 # Do not accept source routing net.ipv4.conf.default.accept_source_route = 0 # Controls the System Request debugging functionality of the kernel kernel.sysrq = 0 # Controls whether core dumps will append the PID to the core filename. # Useful for debugging multi-threaded applications. kernel.core_uses_pid = 1 > > it says iptables and has this part: > > # Forward all packets from eth1 (internal network) to > eth0 (the public internet) > > iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT > > # Forward packets that are part of existing and > related connections from eth0 to eth1 > > iptables -A FORWARD -i eth0 -o eth1 -m state --state > ESTABLISHED,RELATED -j ACCEPT > > # Enable SNAT functionality on eth0. a.b.c.d are > generally the ip of the eth0 > > iptables -A POSTROUTING -t nat -s 192.168.1.0/24 -o > eth0 -j SNAT --to-source a. > > > > I added everything here except last line "Enable > SNAT", I do not know what that means, I know it is > close. I can ping the host machine, it gets an ip, it gets > DNS, and all, but cannot surf :( > > Anywhere you send packets needs some way to get the > response back to the sender. One way to do this is to plan > things so all of your private subnets are unique and add > routes toward the gateway interfaces for everything else. > Another way is to NAT the source address as it goes out the > already-known interface. That way the rest of the world > does not need to know about your new private subnet. As a > packet goes out, the source address of the client will be > replaced with the address of the forwarding interface and > the host performing this will maintain a table of > connections to do the reverse mapping as the reply packets > come back. If you tcpdump your eth0 interface now, > you'll probably see packets being forwarded out but > nothing coming back because the rest of the net/world > doesn't know the route back. When you add the SNAT, it > will look like the host machine itself to the rest of the > world. The argument to -s is the range of original > addresses to replace, -o is the outbound interface, and > --to-source is the IP of the outbound interface on the host. > > -- Les Mikesell > lesmikesell@xxxxxxxxx The rest of the local network does not have to know about this one, but I have not done this before, I have tried but not succeeded, now I know that I am close, but not there yet. Just need a few more hints/advice and it will work :) This appears to have been removed, the rules to forward using iptables :( [root@localhost ~]# cat /etc/sysconfig/iptables # Firewall configuration written by system-config-securitylevel # Manual customization of this file is not recommended. *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :RH-Firewall-1-INPUT - [0:0] -A INPUT -j RH-Firewall-1-INPUT -A RH-Firewall-1-INPUT -i lo -j ACCEPT -A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT -A RH-Firewall-1-INPUT -p 50 -j ACCEPT -A RH-Firewall-1-INPUT -p 51 -j ACCEPT -A RH-Firewall-1-INPUT -p udp --dport 5353 -d 224.0.0.251 -j ACCEPT -A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT -A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT -A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT -A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited -A FORWARD -j REJECT --reject-with icmp-host-prohibited COMMIT [root@localhost ~]# Thank you very much for trying to help. Now there's also ip6tables, but I do not want to go there yet :( Regards, Antonio -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines