[NBLUG/talk] Sending to Comcast mailserver woes....
troy at zenux.net
Mon Nov 19 19:44:04 PST 2007
On Mon, Nov 19, 2007 at 06:02:24PM -0800, Mark Street wrote:
> I am still having fits with sending mail to comcast and a few other domains
> for the past month. Nothing has changed in my firewall in the past year or
> so..... but I believe I have narrowed it down to my firewall - iptables - one
> on a Red Hat 9 box and one on a CentOS 5 box. If I turn off my firewall I
> can send mail to comcast.net. If I turn it back on and try to send I get
> entries in /var/log/messages that show mx2.comcast.net or mx1.comcast.net
> sending an ACK SYN to a random high port on my machine. It does this for
> about 15 seconds, then sends a ACK RST. The mail never goes out.
> I have edited my firewall script and turned off all ICMP filtering with no
> positive effect. Can anyone give me a clue as to why comcast insists on
> coming back with a 3 way handshake and how I can tweak my firewall to
You echoing anything funky into /proc/sys/net/ipv4/* ?
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