iis smtp nntp: Hi,

I have 3 VLANs configured on my domain, one VLAN has the web sevrer which is
configured with SMTP and routes mail fine, another VLAN which can send email
to the web server and get its mail processed, however I have the last VLAN
which also sends email to this web server but doesnt get processed. I've
checked the properties of the virtual SMTP server and there are no
restrictions on who can send email to this server.

There are no errors in any logs that I have found, however using wireshark I
see that the server is sending a SYN packet to the web server and imediately
being sent back a RST packet to the sending server.

Below is what I get from wireshark. (the 192.168.104.166 is the server that
cant send emails, and 192.168.101.200 is the SMTP/Web sevrer)

241 0.668698 192.168.104.166 192.168.101.200 TCP 63102 > smtp [SYN] Seq=0
Win=65535 Len=0 MSS=1460
242 0.668782 192.168.104.166 192.168.101.200 TCP 63102 > smtp [RST] Seq=1
Win=0 Len=0

Under the description of the packet I also get the below message:

"Acknowledgment number: Broken TCP. The acknowledge field is nonzero while
the ACK flag is not set"

Can anyone help me with this one? I'm using Windows 2003 SP1.

[quoted text, click to view]

Even in a vanilla Windows install, there are other areas to check if
you see connection resets, in addition to the IIS SMTP access control
list:

- Windows firewall policy (local and GPO)

- IPSec policies (local and GPO)

Other than those areas, look on the source machine. Your WS snippet
actually seems to show the RST coming from the source, not the
intended destination. Or else you are missing some traffic.

--Sandy



------------------------------------
Sanford Whiteman, Chief Technologist
Broadleaf Systems, a division of
Cypress Integrated Systems, Inc.