Hi guys,<div><br></div><div>I happen to be on two ISPs [therefore two public IPs. My mail server uses an ISP [ISP-A] whose link which has been annoyingly erratic since yesterday. I wish to route my outgoing emails through the other ISP [ISP-B], but some servers reject our mails when we use that link due to inconsistent PTR records. What I mean is this: <a href="http://mail.mydomain.co.ke">mail.mydomain.co.ke</a> resolves to my ISP-A [public] IP address. When I route to ISP-B, the EHLO message would show a connection coming from <a href="http://mail.mydomain.co.ke">mail.mydomain.co.ke</a>, but the PTR would not be equal to the IP given by ISP-B [from which the email actually originates] and that is why some mail servers drop the connection at that point.</div>

<div><br></div><div>Now my question: Is there a way I can combine dvert traffic to go out through my ISP-B box such that traffic appears to be from ISP-A? I tried using SNAT yesterday and it didnt work. </div><div><br></div>

<div>Experiment: I was also wondering whether it is possible to route traffic based on the destination port, i.e. my mail and squid proxy server is <a href="http://192.168.80.1/24">192.168.80.1/24</a> and also has <a href="http://172.16.10.2/29">172.16.10.2/29</a>. The ISP-A box is <a href="http://172.16.10.1/29">172.16.10.1/29</a> and ISP-B is <a href="http://172.16.10.3/29">172.16.10.3/29</a> [not their real IPs :-P]. I would like to make the default gateway for my mail and internet server 172.16.10.3, but route outgoing SMTP only traffic through 172.16.10.1. I know port numbers are dealt with in the transport layer while routing is a lyer 3 affair, but Ibelieve all things are possible in computing.</div>

<div><br></div><div>I would appreciate your ideas, suggestions, criticisms and even blank replies as are normally sent by some.</div><div><br></div><div><br></div><div>Me.</div>