Microsoft and Teredo

Nathan Ward nanog at
Fri Jun 1 00:40:56 UTC 2007

On 1/06/2007, at 2:24 AM, <michael.dillon at>  
<michael.dillon at> wrote:

>> In perfect time, this was published yesterday, to answer that very
>> question:
>> teredosecconcerns-00.txt
> Unfortunately, he doesn't say much in the way of solutions. For
> instance, if a company has internal IPv6 connectivity to their ISP,  
> then
> presumably, Teredo is not needed. The problem then becomes one of
> firewall vendors supporting IPv6. He positions it as a problem that
> needs awkward workarounds such as blocking Teredo or patching Windows.
> He gives up on firewall vendors and only looks at their ability to do
> deep packet inspection by unencapsulating tunneled traffic. But plain
> ordinary IPv6 support from firewall vendors is not mentioned.

He doesn't mention native IPv6 as it's a Teredo document.

> In any case, this draft is directed at the enterprise which rigorously
> firewalls all ingress/egress traffic at the edge.

Yes, I don't know if possible security concerns with Teredo are  
applicable to ISPs, unless you offer a firewalled service. Then those  
concerns are really the same as an enterprise.

Nathan Ward

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