Scott,

Thanks for responding.  Unfortunately, I think my situation is a little more dire, or at least involved.   I probably should have said this before, but I had done TCP 25 outbound testing from our /23 to various .MIL MX's that I know were responding and could not establish a connection / get an SMTP banner.   I could then go to Azure, or Digital Ocean, or somewhere else that I have a box and am able to make the outbound connection to the same MIL MXs that wouldn't respond to me from our /23.

So it isn't a simple case of DNS not resolving, although we certainly did notice that issue.  Fortunately, we do have nameservers in place that are external to our /23 and which are able to actually do the resolving.   But your comment does remind that this definitely is not just a TCP 25 issue, as the MIL DNS servers are not responding to queries from our /23 hosts.

The situation is difficult for multiple reasons:

1.  inabiity to engage somebody from the other end - DISA
2.  Unwillingness on my part to stab at a hornets nest and poke around trying to verify connections (other than TCP 25 to known MIL MXs) in DOD-land.
3.  Not knowing exactly where to go from here

The latest/last thing DISA told me was that I would have to get one of the people with MIL email addresses who can't email our customers to actually open a ticket with DISA.   And that is fraught with problems since even if a MIL email user did open a ticket, they would not have any information about our network to convey to the Helpdesk -- and would have no way of answering questions that the Helpdesk asked, and also wouldn't be able to do any troubleshooting.

I did realize a few days ago we had no ROA for the specific /23, and so I created one at ARIN.   And we had no specific route object published for our /23, and I got one added.   Been trying to clean up some old (and invalid) stuff that is in RADB from our larger /19, since we don't even own all the space in the /19 anymore and are only actively using a /23 from what we have left.   Hoping to get that taken care of Monday.

Everything has worked fine for 26 years, until Jun 1.   But things change, and I'm obviously behind the times given that I didn't have proper ROA and route object in place.

Mike Tindor

On Sat, Jun 29, 2024 at 11:26 AM Scott Q. <qmail@top-consulting.net> wrote:
There are DISA folks lurking here.

I had a similar issue where our block was labeled as residential by their new firewall, and DISA front-desk isn't yet trained on this mechanism so they can't help.

I escalated the issue to a lot of groups but in the end I gave up, too much bureaucracy. The issue is simply DNS - their DNS servers don't let you resolve. So I simply set 8.8.8.8 as the resolver for *.mil and it temp (permanently) fixed the problem.

Scott


On Saturday, 29/06/2024 at 09:16 Mike Tindor wrote:
Hi folks,

I'm looking for a DISA/DOD contact who feels that my issue has merit.   I've tried the DISA Helpdesk and have been told since I'm a commercial entity with no affiliation with the DOD, they can't help me.

The issue at hand is that our /23 netblock has lost communication (at least email TCP 25) with AS345 / AS721 as of May 31, 2024 and I cannot figure out why.   We are in a Flexential datacenter in Richmond VA and use Flexential for transport.   We cannot send emails to .MIL or receive emails from .MIL.  It is not that they are being rejected on either end.   The deliveries are timing out and being returned to sender, from both sides.

I don't know if DISA/DOD has a block on our ASN  and-or /23, or if there is a routing issue somewhere between us and AS345 / AS721.  I had asked the Flexential folks to look into it from their side, and they indicated that historic data does indeed show that there TCP 25 communications to and fro between us and AS345 prior to June 1, but nothing from June 1 onward.  And all they could say was that they (Flex) were not in any way blocking.  And I'd agree with that.

As you can imagine, my customers are not happy with not being able to communicate with their family / friends via email in the MIL domains, and our customers who are vendors / contractors cannot do business with the military effectively if they cannot send/receive emails.

 us --> Flexential --> GTT --> Level3 --> Qwest --> ? --> AS345 / AS721

Any idea where one would go next?   Is it likely that any of those entities further upstream like GTT / Level3 / Qwest would even assist since we are not their customer?

Thanks for your time!

Mike Tindor