nanog mailing list archives

Re: ASNs decimation in ZW this morning


From: Mark Tinka <mark.tinka () seacom mu>
Date: Thu, 17 Jan 2019 11:07:49 +0200



On 16/Jan/19 19:49, John Von Essen wrote:

Im confused as to what exactly happened and how it was implemented. I
assume the government wanted to restrict access to sites like
whatsapp, facebook, twitter, etc.,. So did they tell national
ISPs/Mobile (strong-arm) to simply block access to those sites, or
they did they tell them to completely shutdown and go dark until the
protests were over. Im just curious as to how an ISP/Mobile would
selectively block access under government influence, reason being...
understanding how can help us think of ways to get around it.

For example, lets say the mobile networks null routed all traffic
destined to twitter and facebook networks... not a complete IP
shutdown. So a local citizen is using email from a local provider
(non-gmail, etc.,.) and still has access to email, Twitter knows they
are blocked in ZW, but they still try to email updates to this example
citizen. If their networks are being null routed, they can simply
deliver the email via an alternate network/platform.

The whole thing is very disturbing, I mean this is 2019 right? Not
1984...

It's not unusual for networks to be shutdown, particularly during riots
and/or elections. I'm not saying it's right or wrong, I'm just saying
it's not unusual.

This happened during the recent elections in Uganda and Kenya, for example.

Typically, the operating licenses issued by the gubbermints to operators
provide for legal avenues by the gubbermint to shutdown services. It is
not the gubbermint's responsibility as to how this is implemented by the
operators, just that it be done.

In recent years, social media resources have been targets, so Facebook,
WhatsApp, Twitter et al. However, if the gubbermint takes a broader
approach, it's up to the operator to figure out how to do it. Failure to
comply can result in arrests, fines, jail or even revocation of the license.

All mobile operators have terribly advanced DPI infrastructure, so it's
not difficult to shut services down at a very granular level.

Operators that deliver services via terrestrial means also employ DPI
infrastructure, because selling bandwidth access by the Gig-loads is big
business :-\. So they, too, can implement shutdowns with a reasonable
degree of granularity.

Mark.


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