Possible Neotel Broadband Mail vs DNS issue

[donaldjfraser]

Possible Neotel Broadband Mail vs WebAfrica DNS issue

Hi everyone,

We are connected using a Neotel NeoInternet 15Mbps connection.

We have a peculiar problem where we can not connect to our incoming mail server hosted at WebAfrica every hour, for 20 minutes, lasting for about 20 - 22 minutes. This happens every day at 20 minutes to the hour like clockwork, e.g. at 8:40 we can not connect to the mail server for 20 minutes. This is repeated at 9:40, 10:40 etc.

This only happens when we are on the Neotel connection. 3G, Telkom ADSL etc. does not have this issue.

Some facts during the 20 minute problematic time period:

* We can still send mails using the same mail server url or IP, and IMAP also works. It is just incoming POP mail that is affected.

* I can still ping our mail server name, WebAfrica server name (lnxwebr05.cpt.wa.co.za) and Webafrica IP (41.185.8.55). Same for traceroutes.

* I can not Telnet using port 110, but port 25 does work. After the period Telnet to 110 works again.

* Traceroute, pings and nslookup records are unchanged before, during and after the period.

* I've tried different firewalls (Symantech and Mikrotik)

* There has been no hardware or software changes.

Neotel says it's not them, WebAfrica says it is not them!

Any other ideas on what to test for and where to look for the cause?

 

[web_dude]

Maybe your firewall is giving problems ????

I use neotel for the last 3 years and I haven't experience any issues. (My mail is Google Apps, anyway).

 

[donaldjfraser]

Maybe your firewall is giving problems ????

I use neotel for the last 3 years and I haven't experience any issues. (My mail is Google Apps, anyway).

I have swapped out the firewall with no luck, and also used a Mikrotik Routerboard which does no filtering of any kind.

We never had this issue before, it's only been occurring in the last month or so. There has been no hardware or software changes of any sort here.

 

[Nuro]

We use NeoBroadband Fibre, not sure if it's similar. If you have static ip's, configure a machine directly on one of the static ip's, bypassing any firewalls except the router they provided, and run your tests again. Also, try using secure POP3 (SSL, port 995) if Webafrica provides it.

 

[donaldjfraser]

We use NeoBroadband Fibre, not sure if it's similar. If you have static ip's, configure a machine directly on one of the static ip's, bypassing any firewalls except the router they provided, and run your tests again. Also, try using secure POP3 (SSL, port 995) if Webafrica provides it.

No change. Plugged my Mac straight into the Neotel router using their static IP , DNS & gateway and got the same result.

I have tried both SSL & 995, 465 and normal port 110, none of which work during that period.

 

[Nuro]

That is so strange. Have you tried a different mail server, perhaps different provider during the outages? I recently had a mail server block me randomly, but it was during the whole day, and the provider fixed it.

 

[donaldjfraser]

I tried different mail servers, all with success.

New development though: When testing the ports on each path on the trace routes, one of Internet Solution's routers (ar2-rba-gi0-1.ip.isnet.net) is giving me a closed port on 110 during the problematic 20 minutes, and then fine again afterwards.

When using different connections (Vodacom 3G) that router does not come up. Now to try and convince Webafrica or Neotel to get in touch with IS to confirm. Yayness. Not a lot of faith in that. In the mean time trying to get techies to route all POP traffic to our mail server through the Mikrotik over to our ADSL redundency.