Forum Discussion
Jim_Munroe_4488
Nimbostratus
NimbostratusOptions for preserving real Source IP for SMTP IIS Logging w/ SNAT
Hello,
Looking for a way to preserve the real src IP address with in the IIS 6.0 SMTP logs. Using BigIP with SNAT to Load balance between multiple IIS based SMTP servers. Due to reporting restrictions we require the real server's IP address as the source rather than the IP address of the BigIP. We are running the latest version of 9.x.
Any ideas or input would be greatly appreciated.
Thanks,
Jim
5 Replies
- Hi Jim,
Check out the iControl code share section for an IIS plugin:
http://devcentral.f5.com/Default.aspx?tabid=38
Cheers,
Tom. - dennypayne
Employee
That plugin converts the X-Forwarded-For header (inserted in an HTTP profile) into the client address in the IIS logs. However, since Jim is trying to do this for SMTP he will not be able to utilize the HTTP header insert.
Denny - Assuming I understand your question...
If you can can set the default GW for the SMTP servers so that return traffic is routed through the BIG-IP, then you can eliminate the SNAT of inbound client IP's, and SNAT only the outbound sessions initiated by the SMTP servers.
HTH
/deb 
Kevin_82627So is there no other way to accomplish this other than to set the default gateway back to the F5? (I mean for non-http protocols like imap and ldap.)
hoolioCirrostratus
Hi Kevin,
Changing the server's default gateway would be the simplest option in terms of LTM configuration.
You could also try nPath where you have the servers respond back directly to the clients using the LTM VIP address. Try searching the forums or AskF5.com for details on nPath.
Aaron
