Submitting Messages on Port 587 from F5 SMTP Mailer failing with AUTH GSSAPI Remote(SocketError)
when i bypass F5 load balancer its submitting messages directly to the exchange server without any issues.
When i am submitting via F5 . I can see its initiating AUTH GSSAPI protocol from the listed supported protocols and fails to Submit the Message.
Default log location
%ExchangeInstallPath%TransportRoles\Logs\FrontEnd\ProtocolLog\SmtpReceive
2019-08-19T08:38:51.744Z,EXCH1\Client Frontend EXCH1,234255E01EE2EF03,2,172.21.11.231:587,172.21.1.10:39534,<,EHLO F5DMZ, 2019-08-19T08:38:51.744Z,EXCH1\Client Frontend EXCH1,234255E01EE2EF03,3,172.21.11.231:587,172.21.1.10:39534,>,250 EXCH1.azure365pro.com Hello [172.21.1.10] SIZE 37748736 PIPELINING DSN ENHANCEDSTATUSCODES STARTTLS AUTH GSSAPI NTLM 8BITMIME BINARYMIME CHUNKING,
2019-08-19T08:38:51.746Z,EXCH1\Client Frontend EXCH1,234255E01EE2EF03,4,172.21.11.231:587,172.21.1.10:39534,<,AUTH GSSAPI, 2019-08-19T08:38:51.747Z,EXCH1\Client Frontend EXCH1,234255E01EE2EF03,5,172.21.11.231:587,172.21.1.10:39534,>,334 ,
2019-08-19T08:38:52.797Z,EXCH1\Client Frontend EXCH1,234255E01EE2EF03,6,172.21.11.231:587,172.21.1.10:39534,-,,Remote(SocketError)
Disabled GSSAPI from Listed Available Protocols – Setting EnableAuthGSSAPI to $false
Set-ReceiveConnector "EXCH1\Client Frontend EXCH1" -EnableAuthGSSAPI $false
To CheckÂ
Get-ReceiveConnector "EXCH1\Client Frontend EXCH1" | fl *binding*,*GSS*
Applied the same for all members in the pool of Exchange Servers
Once Disabled. It submitted the message without any issues.
To Revert Back –
Set-ReceiveConnector "EXCH1\Client Frontend EXCH1" -EnableAuthGSSAPI $true
when i bypass F5 load balancer its submitting messages directly to the exchange server without any issues.){kind=link}