dnsstuff.com can ping but cannot connect -> no incoming external

[paulha]

Afternoon everyone

Running W2K Server SP4+ and E2K SP3+, GFI

Yesterday afternoon we stopped receiving external emails.

Testing at dnsstuff.com allows us to ping the server, but cannot connect when doing a mail test, get error message "[Could not connect: Could not connect to mail server (timed out).]

I can telnet to the server on the LAN and send and receive a test from my breathe.com mail account, can't telnet from a dialup, get a "could not open connection to the host message"

Without wishing to sound like one of my users ;-) nothing has changed on the server or firewall that I am aware of.

Nothing of any note in the event logs

Not sure if this is relevant, but there is a small red mark above the mailbox store icon in ESM

Any help would be greatly appreciated

Thanks in advance

Paul

 

[paulha]

Looking agin at the red mark, it may well be a stamp on the envelope icon, and has possibly always been there

//oops

 

[Serbtastic]

Maybe your ISP started blocking inbound port 25? Check the firewall logs for errors.

 

[cygnusman]

Paul,

Did the service started again after about 24 to 36 hours with no intervention on your part??

If so then this is exact same thing I have experienced 3 times in the last 3 months!

I have not been able to find a reason or a fix.

Can I ask ..... Where are you based and what Mail Service Provider you use??

Regards,

Dave

 

[paulha]

Afternoon Dave

I was unable to figure it out myself, as we suspected a firewall / router problem, either at ourselves or at our ISP. We contracted the support team at the place that holds our hardware contract to sort it out, as Pix/router knowledge here is somewhere between non existant and very slim

I have limited feedback at the moment, they made some limited changes to the ISP pix, as well as ours apparently, rebooted the exchange box, and bob was our uncle.

I will provide more feedback tomorrow when I speak to the engineer.


Two worrying things from the whole excersise are :

1. Neither us nor the ISP made any firewall changes

2.For months now I was convinced I was going senile as I couldnt access our Pix, thought I had forgotten the password. The ext engineer accessed it using the default Cisco pw, found it to be running a beta version of the software it should have been running. Almost as if someone had wanted to access it and overinstalled the beta to get round the password I had been using. Have got it back to a secure pw, will monitor it a bit more regularly in future !

Paul

 

[cygnusman]

Paul,

IMHO it's nought to do with the firewalls your side or your Exchange 2K box. When we had the problem I spent a day going thru the usual tests with a MS Exchange engfineer. He gave our Exchange 2K system a clean bill. I also tried 3 other router/firewalls that we have (for emergencies) - in each case we had the same lack of inbound connectivity.

The MS Exchange guy was convinced the problem rested with the Service Provider. Like I said - connectivity returned 'all on it's own' after 24 to 36 hours.

My theory is that there are things done by Engineers in the chain ABOVE your Service Provider that have knock on affects at our level.

Cheers,

Dave

 

[paulha]

Could well be the case. All working fine now, except the GFI anti-spam has stopped filtering now. Keeps me a job though !

Thanks for your input Dave (& Serbtastic)

Cheers

Paul