Outbound port blocking and Exchange 5.5

Outbound port blocking and Exchange 5.5

Post by Jsn.. » Wed, 18 Jul 2001 22:55:53



I have blocked most outbound ports on my firewall except for the ones
we use and as a result I cannot recieve email.  I am running a Winnt
network with Exchange 5.5 and a Watchguard SOHO firewall.  After
blocking outbound ports I view the SOHO event log to see successfull
inbound port 25 traffic but immediately follow an accepted port 25
packet I see a rejected outbound packet from my exchange server.  The
outbound port in question seems to be random based on the source IP.  

Can anyone there help me find a registry hack for exchange to specify
these outbound port ACK's?  

 
 
 

Outbound port blocking and Exchange 5.5

Post by Kirill S. Palagi » Wed, 18 Jul 2001 23:15:55


AFAIK, all SMTP communications are happen via port 25. Open port 25 completely
and see what happens. Also, does your f/w give you information on the nature of
packet?


> I have blocked most outbound ports on my firewall except for the ones
> we use and as a result I cannot recieve email.  I am running a Winnt
> network with Exchange 5.5 and a Watchguard SOHO firewall.  After
> blocking outbound ports I view the SOHO event log to see successfull
> inbound port 25 traffic but immediately follow an accepted port 25
> packet I see a rejected outbound packet from my exchange server.  The
> outbound port in question seems to be random based on the source IP.

> Can anyone there help me find a registry hack for exchange to specify
> these outbound port ACK's?

--
Corrections are welcome.
Please keep all discussions in NG, so that everybody can participate.

Kirill

 
 
 

Outbound port blocking and Exchange 5.5

Post by Jsn.. » Fri, 20 Jul 2001 01:59:19


I have port 25, 110, 443, and a few other registered ports open.  I do
not have the ability to look at packet specific details with the
firewall.  What I see is an inbound packet on port 25 from outside IP
x.x.x.x accepted through the firewall, then immediately see a blocked
outboun packet from exchange server IP x.x.x.x on a high level
un-registered port.

Jason

 
 
 

1. Outbound port blocking and Exchange???

I have blocked most outbound ports on my firewall except for the ones
we use and as a result I cannot recieve email.  I am running a Winnt
network with Exchange 5.5 and a Watchguard SOHO firewall.  After
blocking outbound ports I view the SOHO event log to see successfull
inbound port 25 traffic but immediately follow an accepted port 25
packet I see a rejected outbound packet from my exchange server.  The
outbound port in question seems to be random based on the source IP.  

Can anyone there help me find a registry hack for exchange to specify
these outbound port ACK's?  

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