Opened 9 months ago

Last modified 5 months ago

#33225 new enhancement

Prop 311: 4.4.1. Extend IPv6 From All Supported Second-Last Hops

Reported by: teor Owned by:
Priority: Medium Milestone: Tor: 0.4.5.x-final
Component: Core Tor/Tor Version:
Severity: Normal Keywords: ipv6, prop311
Cc: Actual Points:
Parent ID: #33221 Points: 0
Reviewer: Sponsor: Sponsor55-can


This is an optional change.

This change has a zero points estimate, because I think it is the fastest way of implementing #33222. (The alternative design requires creating different circuit types for IPv4 and IPv6 reachability checks.)

4.4.1. Extend IPv6 From All Supported Second-Last Hops

The testing relay (or bridge) puts both IPv4 and IPv6 ORPorts in its final
extend cell, and the receiving ORPort is selected at random by the
extending relay (see sections 3.2.1 and 4.2). Therefore, approximately half
of IPv6 ORPort reachability circuits will actually end up confirming IPv4
ORPort reachability.

We propose this optional change, to improve the rate of IPv6 ORPort
reachability checks:

If the second-last hop of an IPv4 ORPort reachability circuit supports IPv6
extends, testing relays may put the IPv4 and IPv6 ORPorts in the extend
cell for the final extend.

As the number of relays that support IPv6 extends increases, this change
will increase the number of IPv6 reachability confirmations. In the ideal
case, where the entire network supports IPv4 and IPv6 extends, IPv4 and IPv6
ORPort reachability checks would require a similar number of circuits.

See proposal 311, section 4.4.1:

Child Tickets

Change History (3)

comment:1 Changed 9 months ago by teor

Owner: teor deleted

Un-assign myself from Sponsor55-can tickets.

comment:2 Changed 8 months ago by teor

Status: assignednew

Change tickets that are assigned to nobody to "new".

comment:3 Changed 5 months ago by nickm

Milestone: Tor: 0.4.4.x-finalTor: 0.4.5.x-final
Parent ID: #33222#33221
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