On Tue, 2012-05-01 at 02:08 -0500, Cbulist wrote: > On 05/01/2012 02:03 AM, Barry Brimer wrote: > >> Yes, I thought the same but my confusion is that I don't see any rules of > >> PREROUTING and POSTROUTING in the /etc/sysconfig/iptables file. > >> > >> [root at VS01]# cat /etc/sysconfig/iptables > >> # Firewall configuration written by system-config-firewall > >> # Manual customization of this file is not recommended. > >> *filter > >> :INPUT ACCEPT [0:0] > >> :FORWARD ACCEPT [0:0] > >> :OUTPUT ACCEPT [0:0] > >> -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT > >> -A INPUT -p icmp -j ACCEPT > >> -A INPUT -i lo -j ACCEPT > >> -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT > >> -A INPUT -m state --state NEW -m udp -p udp --dport 631 -j ACCEPT > >> -A INPUT -m state --state NEW -m udp -p udp --dport 5353 -d 224.0.0.251 -j > >> ACCEPT > >> -A INPUT -m state --state NEW -m tcp -p tcp --dport 631 -j ACCEPT > >> -A INPUT -m state --state NEW -m udp -p udp --dport 631 -j ACCEPT > >> -A INPUT -j REJECT --reject-with icmp-host-prohibited > >> -A FORWARD -j REJECT --reject-with icmp-host-prohibited > >> COMMIT > >> > >> > >> But when I check the command iptables -L -t nat I can see the NAT rules > >> > >> [root at VS01]# iptables -L -t nat > >> Chain PREROUTING (policy ACCEPT) > >> target prot opt source destination > >> > >> Chain POSTROUTING (policy ACCEPT) > >> target prot opt source destination > >> MASQUERADE tcp -- 192.168.122.0/24 !192.168.122.0/24 masq ports: > >> 1024-65535 > >> MASQUERADE udp -- 192.168.122.0/24 !192.168.122.0/24 masq ports: > >> 1024-65535 > >> MASQUERADE all -- 192.168.122.0/24 !192.168.122.0/24 > >> MASQUERADE tcp -- 192.168.100.0/24 !192.168.100.0/24 masq ports: > >> 1024-65535 > >> MASQUERADE udp -- 192.168.100.0/24 !192.168.100.0/24 masq ports: > >> 1024-65535 > >> MASQUERADE all -- 192.168.100.0/24 !192.168.100.0/24 > >> > >> Chain OUTPUT (policy ACCEPT) > >> target prot opt source destination > >> > >> am I missing something? > > Maybe .. do you have IPv4 forwarding enabled? What is the output of > > "cat /proc/sys/net/ipv4/ip_forward" ?? If it is 0, then edit > > /etc/sysctl.conf .. find net.ipv4.ip_forward .. set it to 1 and then run > > (as root) sysctl -p > > > In the Host machine the ip_forward is 1 If you restart libvirtd it should add in the IPTABLES rules you are missing.