When you ran the ping tests, did you try all sizes from 56-1500 with no
fragment flag set?  I've seen a case where 2 random sizes didn't pass which
resulted in some very bizarre behavior.  ;-)

-Hal

On Thu, Oct 30, 2014 at 8:58 PM, Bill Prince via Af <[email protected]> wrote:

>
> This is a bizarre set of symptoms, and I really don't know what is going
> on.  So I will articulate the facts, and maybe one of you can tell me what
> might be wrong.
>
> We have a business subscriber that occupies several buildings.  The
> buildings are separated by enough distance that we have to interconnect by
> means other than vanilla ethernet.
>
> Our service is delivered to their main office.  Our SM is installed there
> (PMP450), plus a Mikrotik router on ROS 5.26.  The Mikrotik manages 4
> VLANs; 1 business VLAN, which is bridged to the main subnet in the main
> office.  The other 3 VLANs are guest VLANs; each on their own (private)
> subnet.
>
> All the computers, etc. work fine in the main office.
>
> The main office is connected to the "guest building" with a VDSL modem (~~
> 800' phone line between buildings).  Not much occurs in the guest building;
> it has a couple of WiFi APs for the guests.
>
> In the guest building, we've installed an RB260GS switch.  It divides the
> various ports out to 4 different VLANs.  A couple ports are the "business
> VLAN", plus 3 different "guest VLANs".  The SFP port on the RB260GS is used
> to connect to the "satellite office" another couple hundred yards beyond
> the guest building.  The SFP port is on the business VLAN.
>
> At the satellite office, they have 2 computers.  Everything on the 2
> computers in the satellite office seems to work just fine.  Web browsing,
> streaming youtube, etc.
>
> However, when they run Outlook, "some" email doesn't go to the
> destination.  As far as we can tell, it gets to their off-site SMTP server
> (Globat), but some of it doesn't ever reach its destination. If they use
> their web-based email, the email works every time. Also, the POP part of
> the email works just like you'd expect.
>
> Today, we moved one of the computers back to the main office, and
> surprise, surprise, Outlook starts working just like it's supposed to.
>
> We've run extended ping tests between the satellite office and the main
> office, and there is no break in the link.  It seems solid.  So where/how
> is the SMTP part of email breaking?
>
> What tests can I run to figure this out?
>
>
> --
> bp
>
>


-- 

Harold Bledsoe

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