Monday, October 13, 2008

Port 25 is for Sissies!

Interesting problem today. Bunch of users couldn't send mail to what seemed to be random domains. A little basic investigating showed that they were all hosted on a particular Network Solutions mail server. Seems as though NetSol had a series DoS attacks against them back in August and had blocked entire IP ranges. I could get to the NetSol server from some locations, but not others.

My first call to Network Solutions was fruitless. I spent a great deal of time explaining to the poor tech on the other end that I was not a NetSol customer but someone trying to email a NetSol customer. After great lengths, I was told to configure my Outlook client to use ports 110 and 2525 for communicating. Umm. No.

The second call was much better. I landed at a tech who understood what it meant when I said I could't telnet to this particular mailserver from my netblock. Ticket opened, but I'm sure it will be promptly dropped in the bit bucket.


  1. Still no follow up from the delightful netsol. They suck.

  2. Never got any follow up, but it does turn out that we had some CEF anomalies. It's Cisco's straight-to-the-bit-bucket express forwarding technology. We can route your packet anywhere, so long as the destination is