Description:
Connection sharing wasn't working properly (in Archlinux). 
I could ping to host but there was not package forwarding (no Internet access).
After patching, connection sharing is working again.


Additional info:
* package version(s)
iptables-1.4.12.1-1
networkmanager-0.9.0-1

* config and/or log files etc.

[/var/log/messages.log]

Sep  8 10:02:03 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert INPUT --in-interface eth0 --protocol tcp --destination-port 53 --jump ACCEPT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert INPUT --in-interface eth0 --protocol udp --destination-port 53 --jump ACCEPT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert INPUT --in-interface eth0 --protocol tcp --destination-port 67 --jump ACCEPT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert INPUT --in-interface eth0 --protocol udp --destination-port 67 --jump ACCEPT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert FORWARD --in-interface eth0 --jump REJECT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert FORWARD --out-interface eth0 --jump REJECT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert FORWARD --in-interface eth0 --out-interface eth0 --jump ACCEPT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert FORWARD --source 10.42.43.0/255.255.255.0 --in-interface eth0 --jump ACCEPT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table filter --insert FORWARD --destination 10.42.43.0/255.255.255.0 --out-interface eth0 --match state --state ESTABLISHED,RELATED --jump ACCEPT
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Executing: /usr/sbin/iptables --table nat --insert POSTROUTING --source 10.42.43.0/255.255.255.0 --destination ! 10.42.43.0/255.255.255.0 --jump MASQUERADE
Sep  8 10:02:04 localhost NetworkManager[1125]: <warn> ** Command returned exit status 2.
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Starting dnsmasq...
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> (eth0): device state change: ip-config -> activated (reason 'none') [70 100 0]
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Activation (eth0) successful, device activated.
Sep  8 10:02:04 localhost NetworkManager[1125]: <info> Activation (eth0) Stage 5 of 5 (IP Configure Commit) complete.





And the output of the offending command:

[ignacio@ignacio-desk ~]$ sudo /usr/sbin/iptables --table nat --insert POSTROUTING --source 10.42.43.0/255.255.255.0 --destination ! 10.42.43.0/255.255.255.0 --jump MASQUERADE
[sudo] password for ignacio: 
Bad argument `10.42.43.0/255.255.255.0'
Try `iptables -h' or 'iptables --help' for more information.




Steps to reproduce:
Fresh install, configure internet connection on wlan0 and connection sharing on eth0.