Thanks for having me!
So... I did a fresh install of RHEL v6.7. I was setting up just NTP service and followed some tutorial on the interwebs. At some point is this tutorial it suggested that I should open port udp 123 so the server could receive NTP querys from other clients.
After that fresh install no configuration was done whatsoever.
When I checked the iptables service this is what I got.
[root@SVNTPRJO01 ~]# 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 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'm not a linux guy but reading man pages and some blog posts I understand that because of rule number 3 on the INPUT chain this server would accept anything from anywhere, including udp 123, right?
Is my understanding correct?
This server only has one nic (eth0).