I would like to ask in ubuntu 12.04, there is no firewall settings by default?
iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
However we have default firewall setting that already block major ports already in Centos/Fedora?
iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT icmp -- anywhere anywhere
ACCEPT all -- anywhere anywhere
ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:ssh
ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:webcache
ACCEPT udp -- anywhere anywhere state NEW udp dpt:webcache
ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:8090
REJECT all -- anywhere anywhere reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT)
target prot opt source destination
REJECT all -- anywhere anywhere reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
I would like to ask if there is nth to set in ChainINPUT, does it mean it doesn't block anything in Ubuntu? But what about Centos iptables, it seems other ports are blocked except, webcache 8080, 8090, and ssh port (22)