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As I understand it, Tor uses the same circuit for about 10 minutes or as specified in the MaxCircuitDirtiness option in the torrc file. However, I noticed something strange while trying to use curl to fetch a site while running tor on a separate terminal window.

Initially, the circuit being used was this (with the torrc file set to use an Exit Node in France).

Circuit 2 (GENERAL)
 |- F25BCD77AB5BBA6F5A4D233DD57A51660ECCB9D6 (cleve, 46.166.167.46)
 |- 94FE042E75138ECD76A3B7D6C30A83C6AA71463A (snakeplant, 178.62.180.121)
 +- AFF2FC5C6F793B6E147EB93C1897D6DDA49E54FD (Wix, 5.196.66.162)

Where Wix is supposed to be an Exit Node in France.

I figured this out by first listing the current circuits inside tor, and then using a script to list down the exit node currently being used (Both by using Stem's API). Since the Exit node being used for my connection was Wix, I figured that this was indeed the circuit being used.

However, suddenly, after a a minute or two, I decide to fetch another request, and this time, the exit node came out to be a node in Germany:

And then when I repeat the request again, Tor switches back to the Wix circuit. Here's an image of that:

enter image description here

When I listed down the circuits at that particular time, I noticed a one-node circuit with this particular (which is listed as a Guard node on Atlas) in the list:

enter image description here

A similar thing (as in a sudden switch between the normal French exit-node being used) happened with another node (named clive above). This node too had a one-node circuit, and in addition it was present as a Guard node in all the other circuits in the list.

Could anyone please let me know what could be going on? Why doesn't Tor's circuit stick to the node in the country that I had specified in the torrc file? Why does it suddenly switch to a node in Germany? Or Lithuania in the case of the other node. Does Tor use one-node circuits sometimes on its own? Does this kind of thing normally happen?

Thanks.

EDIT: My torrc file:

## Configuration file for a typical Tor user
## Last updated 22 September 2015 for Tor 0.2.7.3-alpha.
## (may or may not work for much older or much newer versions of Tor.)
##
## Lines that begin with "## " try to explain what's going on. Lines
## that begin with just "#" are disabled commands: you can enable them
## by removing the "#" symbol.
##
## See 'man tor', or https://www.torproject.org/docs/tor-manual.html,
## for more options you can use in this file.
##
## Tor will look for this file in various places based on your platform:
## https://www.torproject.org/docs/faq#torrc

## Tor opens a SOCKS proxy on port 9050 by default -- even if you don't
## configure one below. Set "SOCKSPort 0" if you plan to run Tor only
## as a relay, and not make any local application connections yourself.
#SOCKSPort 9050 # Default: Bind to localhost:9050 for local connections.
#SOCKSPort 192.168.0.1:9100 # Bind to this address:port too.
ExitNodes {fr}
StrictNodes 1
## Entry policies to allow/deny SOCKS requests based on IP address.
## First entry that matches wins. If no SOCKSPolicy is set, we accept
## all (and only) requests that reach a SOCKSPort. Untrusted users who
## can access your SOCKSPort may be able to learn about the connections
## you make.
#SOCKSPolicy accept 192.168.0.0/16
#SOCKSPolicy accept6 FC00::/7
#SOCKSPolicy reject *

## Logs go to stdout at level "notice" unless redirected by something
## else, like one of the below lines. You can have as many Log lines as
## you want.
##
## We advise using "notice" in most cases, since anything more verbose
## may provide sensitive information to an attacker who obtains the logs.
##
## Send all messages of level 'notice' or higher to /var/log/tor/notices.log
#Log notice file /var/log/tor/notices.log
## Send every possible message to /var/log/tor/debug.log
#Log debug file /var/log/tor/debug.log
## Use the system log instead of Tor's logfiles
#Log notice syslog
## To send all messages to stderr:
#Log debug stderr

## Uncomment this to start the process in the background... or use
## --runasdaemon 1 on the command line. This is ignored on Windows;
## see the FAQ entry if you want Tor to run as an NT service.
#RunAsDaemon 1

## The directory for keeping all the keys/etc. By default, we store
## things in $HOME/.tor on Unix, and in Application Data\tor on Windows.
#DataDirectory /var/lib/tor

## The port on which Tor will listen for local connections from Tor
## controller applications, as documented in control-spec.txt.
ControlPort 9051
## If you enable the controlport, be sure to enable one of these
## authentication methods, to prevent attackers from accessing it.
#HashedControlPassword 16:872860B76453A77D60CA2BB8C1A7042072093276A3D701AD684053EC4C
CookieAuthentication 1

############### This section is just for location-hidden services ###

## Once you have configured a hidden service, you can look at the
## contents of the file ".../hidden_service/hostname" for the address
## to tell people.
##
## HiddenServicePort x y:z says to redirect requests on port x to the
## address y:z.

#HiddenServiceDir /var/lib/tor/hidden_service/
#HiddenServicePort 80 127.0.0.1:80

#HiddenServiceDir /var/lib/tor/other_hidden_service/
#HiddenServicePort 80 127.0.0.1:80
#HiddenServicePort 22 127.0.0.1:22

################ This section is just for relays #####################
#
## See https://www.torproject.org/docs/tor-doc-relay for details.

## Required: what port to advertise for incoming Tor connections.
#ORPort 9001
## If you want to listen on a port other than the one advertised in
## ORPort (e.g. to advertise 443 but bind to 9090), you can do it as
## follows.  You'll need to do ipchains or other port forwarding
## yourself to make this work.
#ORPort 443 NoListen
#ORPort 127.0.0.1:9090 NoAdvertise

## The IP address or full DNS name for incoming connections to your
## relay. Leave commented out and Tor will guess.
#Address noname.example.com

## If you have multiple network interfaces, you can specify one for
## outgoing traffic to use.
# OutboundBindAddress 10.0.0.5

## A handle for your relay, so people don't have to refer to it by key.
#Nickname ididnteditheconfig

## Define these to limit how much relayed traffic you will allow. Your
## own traffic is still unthrottled. Note that RelayBandwidthRate must
## be at least 20 kilobytes per second.
## Note that units for these config options are bytes (per second), not
## bits (per second), and that prefixes are binary prefixes, i.e. 2^10,
## 2^20, etc.
#RelayBandwidthRate 100 KBytes  # Throttle traffic to 100KB/s (800Kbps)
#RelayBandwidthBurst 200 KBytes # But allow bursts up to 200KB (1600Kb)

## Use these to restrict the maximum traffic per day, week, or month.
## Note that this threshold applies separately to sent and received bytes,
## not to their sum: setting "40 GB" may allow up to 80 GB total before
## hibernating.
##
## Set a maximum of 40 gigabytes each way per period.
#AccountingMax 40 GBytes
## Each period starts daily at midnight (AccountingMax is per day)
#AccountingStart day 00:00
## Each period starts on the 3rd of the month at 15:00 (AccountingMax
## is per month)
#AccountingStart month 3 15:00

## Administrative contact information for this relay or bridge. This line
## can be used to contact you if your relay or bridge is misconfigured or
## something else goes wrong. Note that we archive and publish all
## descriptors containing these lines and that Google indexes them, so
## spammers might also collect them. You may want to obscure the fact that
## it's an email address and/or generate a new address for this purpose.
#ContactInfo Random Person <nobody AT example dot com>
## You might also include your PGP or GPG fingerprint if you have one:
#ContactInfo 0xFFFFFFFF Random Person <nobody AT example dot com>

## Uncomment this to mirror directory information for others. Please do
## if you have enough bandwidth.
#DirPort 9030 # what port to advertise for directory connections
## If you want to listen on a port other than the one advertised in
## DirPort (e.g. to advertise 80 but bind to 9091), you can do it as
## follows.  below too. You'll need to do ipchains or other port
## forwarding yourself to make this work.
#DirPort 80 NoListen
#DirPort 127.0.0.1:9091 NoAdvertise
## Uncomment to return an arbitrary blob of html on your DirPort. Now you
## can explain what Tor is if anybody wonders why your IP address is
## contacting them. See contrib/tor-exit-notice.html in Tor's source
## distribution for a sample.
#DirPortFrontPage /etc/tor/tor-exit-notice.html

## Uncomment this if you run more than one Tor relay, and add the identity
## key fingerprint of each Tor relay you control, even if they're on
## different networks. You declare it here so Tor clients can avoid
## using more than one of your relays in a single circuit. See
## https://www.torproject.org/docs/faq#MultipleRelays
## However, you should never include a bridge's fingerprint here, as it would
## break its concealability and potentially reveal its IP/TCP address.
#MyFamily $keyid,$keyid,...

## A comma-separated list of exit policies. They're considered first
## to last, and the first match wins.
##
## If you want to allow the same ports on IPv4 and IPv6, write your rules
## using accept/reject *. If you want to allow different ports on IPv4 and
## IPv6, write your IPv6 rules using accept6/reject6 *6, and your IPv4 rules
## using accept/reject *4.
##
## If you want to _replace_ the default exit policy, end this with either a
## reject *:* or an accept *:*. Otherwise, you're _augmenting_ (prepending to)
## the default exit policy. Leave commented to just use the default, which is
## described in the man page or at
## https://www.torproject.org/documentation.html
##
## Look at https://www.torproject.org/faq-abuse.html#TypicalAbuses
## for issues you might encounter if you use the default exit policy.
##
## If certain IPs and ports are blocked externally, e.g. by your firewall,
## you should update your exit policy to reflect this -- otherwise Tor
## users will be told that those destinations are down.
##
## For security, by default Tor rejects connections to private (local)
## networks, including to the configured primary public IPv4 and IPv6 addresses,
## and any public IPv4 and IPv6 addresses on any interface on the relay.
## See the man page entry for ExitPolicyRejectPrivate if you want to allow
## "exit enclaving".
##
#ExitPolicy accept *:6660-6667,reject *:* # allow irc ports on IPv4 and IPv6 but no more
#ExitPolicy accept *:119 # accept nntp ports on IPv4 and IPv6 as well as default exit policy
#ExitPolicy accept *4:119 # accept nntp ports on IPv4 only as well as default exit policy
#ExitPolicy accept6 *6:119 # accept nntp ports on IPv6 only as well as default exit policy
#ExitPolicy reject *:* # no exits allowed

## Bridge relays (or "bridges") are Tor relays that aren't listed in the
## main directory. Since there is no complete public list of them, even an
## ISP that filters connections to all the known Tor relays probably
## won't be able to block all the bridges. Also, websites won't treat you
## differently because they won't know you're running Tor. If you can
## be a real relay, please do; but if not, be a bridge!
#BridgeRelay 1
## By default, Tor will advertise your bridge to users through various
## mechanisms like https://bridges.torproject.org/. If you want to run
## a private bridge, for example because you'll give out your bridge
## address manually to your friends, uncomment this line:
#PublishServerDescriptor 0
  • Looks like you used .exit notation. Please provide your scripts and your torrc. – cacahuatl Aug 21 '16 at 19:06
  • I used this on stem's website to list circuits and this to list the exit nodes and curl --socks4a 127.0.0.1:9050 google.com to send a request. Adding the torrc above. – QPTR Aug 22 '16 at 2:31
  • 2
    I think it's a directory fetch (internal connection, not really an exit). I'll poke around and confirm or deny, unless someone else beats me to it. – cacahuatl Aug 22 '16 at 5:57
  • Thanks a lot! Does that mean that schnudel is one of the directory authorities/mirrors, and my tor client is trying to make a one-node circuit to try to download the consensus (by forcing schnudel to act as an exit node)? – QPTR Aug 22 '16 at 13:36

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