From fd4716f1ce976c41662046f1022c2546d993c8a2 Mon Sep 17 00:00:00 2001 From: teor Date: Tue, 4 Feb 2020 12:46:47 +1000 Subject: Prop 312: Improve interface address method Explain why some relays may not have any publicly routable interface addresses. Part of 33073. --- proposals/312-relay-auto-ipv6-addr.txt | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'proposals/312-relay-auto-ipv6-addr.txt') diff --git a/proposals/312-relay-auto-ipv6-addr.txt b/proposals/312-relay-auto-ipv6-addr.txt index 29a45f6..98306c7 100644 --- a/proposals/312-relay-auto-ipv6-addr.txt +++ b/proposals/312-relay-auto-ipv6-addr.txt @@ -280,11 +280,19 @@ Ticket: #33073 packets. Instead, it uses the socket APIs to discover the interface address for the socket. - Tor already ignores private IPv4 interface addresses on public relays. - (Binding to private DirPort addresses is supported, for networks that use - NAT.) We propose to also ignore private IPv6 interface addresses. If all - IPv4 or IPv6 interface addresses are private, address resolution should go - to the next step. + Relays that use NAT to reach the Internet may have no publicly routable + local interface addresses, even on the public tor network. The NAT box has + the publicly routable addresses, and it may be a separate machine. + + Relays may also be unable to detect any local interface addresses. The + required APIs may be unavailable, due to: + * missing OS or library features, or + * local security policies. + + Tor already ignores private IPv4 interface addresses on public relays. We + propose to also ignore private IPv6 interface addresses. If all IPv4 or + IPv6 interface addresses are private, address resolution should go to the + next step. 3.2.4. Use Own Hostname IPv6 Addresses -- cgit v1.2.3-54-g00ecf