I have been running a Centos email/web server for years, with a Linode Xen server the last 4 years with almost no trouble.
Since sometime yesterday I have not been able to connect to outbound email (port 25) servers. The mail queue is building up. Other weird things:
- I can traceroute on port 25 to gmail servers and complete, but time out when connecting outbound to these servers
- I just did yum update earlier this afternoon
- I was getting IPV6 connections trying to be set up until I turned off IPV6 in sysctl
- I can receive inbound mail on port 25 just fine, just can't forward it out.
I'm getting dynamic changes in my iptables, for examples:
Chain INPUT (policy ACCEPT) target prot opt source destination DROP all -- cpe-188-129-114-96.dynamic.amis.hr anywhere DROP all -- 190.40.173.185 anywhere DROP all -- 5.200.193.129 anywhere DROP all -- 206.47.254.202 anywhere Chain FORWARD (policy ACCEPT) target prot opt source destination DROP all -- cpe-188-129-114-96.dynamic.amis.hr anywhere DROP all -- 190.40.173.185 anywhere DROP all -- 5.200.193.129 anywhere DROP all -- 206.47.254.202 anywhere Chain OUTPUT (policy ACCEPT) target prot opt source destination
Any ideas? Have I been hacked?