198.18.0.0/15 is reserved and in use by home routers
A user showed up in #tor to ask for help with Tor determining its address incorrectly. Tor published 198.18.0.2 as his/her/its relay's IP address, even though that was not his public IP address.
According to whois, IETF RFC 2544 reserved 198.18.0.0/15:
NetRange: 198.18.0.0 - 198.19.255.255
CIDR: 198.18.0.0/15
OriginAS:
NetName: SPECIAL-IPV4-BENCHMARK-TESTING-IANA-RESERVED
NetHandle: NET-198-18-0-0-1
Parent: NET-198-0-0-0-0
NetType: IANA Special Use
Comment: This block has been allocated for use in
Comment: benchmark tests of network interconnect
Comment: devices. This range was assigned to
Comment: minimize the chance of conflict in case a
Comment: testing device were to be accidentally
Comment: connected to part of the Internet.
Comment: Packets with source addresses from
Comment: this range are not meant to be forwarded
Comment: across the Internet.
Comment: This assignment was made by the IETF in
Comment: RFC 2544, which can be found at:
Comment: http://www.rfc-editor.org/rfc/rfc2544.txtTor should recognize addresses in that netblock as internal.
This is a potential security issue for users who run exit nodes behind screwy home routers which use that netblock for their private addresses.