Iran blocking essentially all encyrpted protocols

Richard Barnes richard.barnes at
Sat Feb 11 21:50:10 UTC 2012

FWIW: A colleague in Iran was able to connect to a server in the US
using HTTPS on a non-standard port (9999).  It appears that the
Iranian government is not blocking TLS/HTTPS per se, but just port
443.  So in principle, if there were just some HTTPS proxies using
non-standard ports, then people would be able to get out.  At least
until (1) the addresses of the proxies become known to the regime, or
(2) they start blocking cross-border TLS altogether.


On Fri, Feb 10, 2012 at 12:07 PM, Marshall Eubanks
<marshall.eubanks at> wrote:
> And in response
> (quoting) :
> “Basically, say you want to look like an XMPP chat instead of SSL,” he
> writes to me, referring to a protocol for instant messaging as the
> decoy for the encrypted SSL communications. “Obfsproxy should start
> up, you choose XMPP, and obfsproxy should emulate XMPP to the point
> where even a sophisticated [deep packet inspection] device cannot find
> anything suspicious.”
> Regards
> Marshall
> On Fri, Feb 10, 2012 at 2:03 PM, Shahab Vahabzadeh
> <sh.vahabzadeh at> wrote:
>> Yes I am from Iran and outgoing TCP/443 has been stoped ;)
>> --
>> Regards,
>> Shahab Vahabzadeh, Network Engineer and System Administrator
>> PGP Key Fingerprint = 8E34 B335 D702 0CA7 5A81  C2EE 76A2 46C2 5367 BF90
>> On Feb 10, 2012, at 9:56 PM, Ryan Malayter <malayter at> wrote:
>>> Haven't seen this come through on NANOG yet:
>>> Can anyone with the ability confirm that TCP/443 traffic from Iran has
>>> stopped?

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