[tor-dev] Please consider allowing /48 for VirtualAddrNetworkIPv6

grarpamp grarpamp at gmail.com
Fri Sep 16 19:20:55 UTC 2016

On Fri, Sep 16, 2016 at 5:13 AM, Alex Elsayed <eternaleye at gmail.com> wrote:
> Hi, I'm using Tor in transparent mode, and I'm running into a rather
> inconvenient behavior.
> VirtualAddrNetworkIPv6 refuses to parse unless the network address given
> is a /40 or broader. However, IPv6 ULA, which makes it very easy to give
> Tor its own subnet no-strings-attached, strictly grants a /48 prefix.
> As a result, I am faced with a choice between deeply suboptimal options:
> 1.) Use VirtualAddrNetworkIPv4, as I've done in the past. This results in
> _fewer_ addresses being available to Tor than an IPv6 /48, which I feel
> illustrates the issues with requiring a /40 quite clearly.
> 2.) Squat on some portion of the IPv6 address space I don't actually own.
> This is entirely unpalatable

This impacts with onioncat as well.
I'm curious as to any /40 rationale, though I suspect a historical
brainfart typo.

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