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donsergio
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ip cloud Mikrotik service has any "Cache?"

Sun Nov 18, 2018 8:16 pm

Hi, I am experiment a strange thing..... does de IP / Cloud of Mikrotik service has any cache?

I´m pinging to an ip/cloud address of a Mikrotik device that I dissconnected last week and still have ping.....

The device is formatted and stored on our wharehouse but I can PING to the device and the location of the IP is near of me.... I checked the IP and isn´t the mine....

What´s happen with this? The first characters xxxxxxxxxx.sn.mynetname.net are the serial number of the device, right? Is impossible that are another device with same id...

Can anyone help me?

Thanks!!
 
mkx
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Re: ip cloud Mikrotik service has any "Cache?"

Sun Nov 18, 2018 8:46 pm

Mikrotik's cloud service will maintain DNS record until it gets explicit disassociation (e.g. when you untick "use ddns" while still having access to the internet). Meaning that if you simply switch off the involved router, cloud service will not automatically remove DNS record[*].
The other thing is: why some device responds to pings ... it is sensible to assume that your ISP assigns IP addresses to their customers randomly (unless customer requested static IP address) and that addresses get re-used shortly. So when pinging your ex-address you're pinging somebody from your neighbourhood.

[*]That piece of information was a surprise for me. I still don't agree with reasoning behind it, personally I'd go with TTL concept here. If a device is not able to renew DNS record in a fairly long time (e.g. once per fortnight), then it most probably can't accept remote connections and DNS record doesn't have much importance.
BR,
Metod
 
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donsergio
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Re: ip cloud Mikrotik service has any "Cache?"

Sun Nov 18, 2018 10:13 pm

Oh, great, then this explain this case..... yes, my isp provide dynamic IP Address, then for this rule.... Mikrotik ddns server keeps old IP until I connect again device, and enable/disable ddns service AND this old IP is now assigned to another ISP client.

Other strange thing are that to access to devices more easy, I create on my VPS one CNAME for each device..... ex:

111111.sn.mynetname.net CNAME server1.mydomain.com
22222.sn.mynetname.net CNAME server2.mydomain.com
33333.sn.mynetname.net CNAME server3.mydomain.com

For this mikrotik long time before I has a CNAME that I delete a few months before.... the surprise is that the CNAME still working... I can ping to the deleted CNAME and it response... (but this I think could be a CNAME propagation bug or something), because all CNAMEs of this devices are deleted of my VPS.

Thanks for your reply!!
 
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donsergio
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Re: ip cloud Mikrotik service has any "Cache?"

Sun Nov 18, 2018 10:18 pm

I make a test with this device, plug, enable ddns service... and now both domains xxxxxxx.sn.mynetname.net and CNAME point to new IP.... when I dissconect mikrotik device PING get "old" IP again....
 
mkx
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Re: ip cloud Mikrotik service has any "Cache?"

Sun Nov 18, 2018 11:52 pm

I make a test with this device, plug, enable ddns service... and now both domains xxxxxxx.sn.mynetname.net and CNAME point to new IP.... when I dissconect mikrotik device PING get "old" IP again....
This is weird. I suggest you to report it to support@mikrotik.com ...
BR,
Metod
 
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donsergio
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Re: ip cloud Mikrotik service has any "Cache?"

Mon Nov 19, 2018 12:50 am

email sent to support....

Lets wait to answer
 
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vecernik87
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Re: ip cloud Mikrotik service has any "Cache?"

Mon Nov 19, 2018 4:57 am

I believe this does not need support attention as it is most likely caused by misconfiguration of old vs new cloud service. Thing is that pre-6.43 RouterOS is using old cloud service. If you upgrade your device WITHOUT disabling cloud service first, the entry will be stuck there forever. New version (6.43+) uses new cloud service. If you enable it, it might take precedence over old service, but as far as I know, it does not disable/delete the old service.

There is very clear warning in changelog about disabling /ip cloud before upgrading to 6.43+ . Same goes when downgrading system - disable it before, enable it after.

Not sure though why Mikrotik took this approach but I guess they had some reason. Since 6.43 release, there has been numerous occurences with advice "downgrade, enable'disable cloud, upgrade again" or vice versa from staff. Personally I consider this approach as unnecessary obstacle. Ideally, only last service should be active. If new cloud receive ddns setting, it should automatically disable and delete old cloud setting. And same should happen when old cloud receive ddns setting - it should disable and delete new cloud setting. That way, people can't possibly make a mistake.

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