[tor-bugs] #8215 [Tor]: Simple Relay: random unknown UDP port in listen mode

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#8215: Simple Relay: random unknown UDP port in listen mode
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 Reporter:  elgo    |          Owner:     
     Type:  defect  |         Status:  new
 Priority:  normal  |      Milestone:     
Component:  Tor     |        Version:     
 Keywords:          |         Parent:     
   Points:          |   Actualpoints:     
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 Hi,

 I'm setting up a simple Tor relay (no exit), and it went fine, until I saw
 that a unwanted port was reported: it's a port that does not show up
 immediatly when starting tor daemon, but after a while.


 Right after tor start:
 # netstat -lpnut | grep tor
 tcp        0      0 0.0.0.0:8890            0.0.0.0:*               LISTEN
 22278/tor
 tcp        0      0 0.0.0.0:8891            0.0.0.0:*               LISTEN
 22278/tor

 After a while, a random UDP port shows up:
 # netstat -lpnut | grep tor
 tcp        0      0 0.0.0.0:8890            0.0.0.0:*               LISTEN
 22278/tor
 tcp        0      0 0.0.0.0:8891            0.0.0.0:*               LISTEN
 22278/tor
 udp        0      0 0.0.0.0:56867           0.0.0.0:*
 22278/tor

 Tor version: 0.2.3.25
 OS: Gentoo AMD64 (hardened profile)

 See config file:
 User tor
 PIDFile /var/run/tor/tor.pid
 Log notice syslog
 DataDirectory /var/lib/tor/data
 SOCKSPort 0
 ORPort 8890
 DirPort 8891
 Nickname XXXXX
 RelayBandwidthRate 5MB
 RelayBandwidthBurst 7MB
 ExitPolicy reject *:*


 I tried to get DNSPort that seems likely to be the only Tor UDP port
 around, but the random port still appears.

 I didn't manage to identify this port though I went through all tor
 manpage and tried to set almost all XXXPort directives to 0 at some point.

 My "to be" Tor relay is behind a NAT, logs report successful setup:
 "Self-testing indicates your ORPort is reachable from the outside.
 Excellent. Publishing server descriptor."
 "Self-testing indicates your DirPort is reachable from the outside.
 Excellent."

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/8215>
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