We assume you read through the relay guide already. This subpage is for operators that want to turn on exiting on their relay.

It is recommended that you setup exit relays on servers dedicated to this purpose. It is not recommended to install Tor exit relays on servers that you need for other services as well. Do not mix your own traffic with your exit relay traffic.

Reverse DNS and WHOIS record

Before turning your non-exit relay into an exit relay, ensure that you have set a reverse DNS record (PTR) to make it more obvious that this is a tor exit relay. Something like "tor-exit" it its name is a good start.

If your provider offers it, make sure your WHOIS record contains clear indications that this is a Tor exit relay.

Exit Notice HTML page

To make it even more obvious that this is a Tor exit relay you should serve a Tor exit notice HTML page. Tor can do that for you if your DirPort is on TCP port 80, you can make use of tor's DirPortFrontPage feature to display a HTML file on that port. This file will be shown to anyone directing his browser to your Tor exit relay IP address.

DirPort 80
DirPortFrontPage /path/to/html/file

We offer a sample Tor exit notice HTML file, but you might want to adjust it to your needs: https://gitweb.torproject.org/tor.git/plain/contrib/operator-tools/tor-exit-notice.html

Here are some more tips for running a reliable exit relay: https://blog.torproject.org/tips-running-exit-node

Exit Policy

Defining the exit policy is one of the most important parts of an exit relay configuration. The exit policy defines which destination ports you are willing to forward. This has an impact on the amount of abuse emails you will get (less ports means less abuse emails, but an exit relay allowing only few ports is also less useful). If you want to be a useful exit relay you must at least allow destination ports 80 and 443.

As a new exit relay - especially if you are new to your hoster - it is good to start with a reduced exit policy (to reduce the amount of abuse emails) and further open it up as you become more experienced. The reduced exit policy can be found on the ReducedExitPolicy wiki page.

To become an exit relay change ExitRelay from 0 to 1 in your torrc configuration file and restart the tor daemon.

ExitRelay 1

DNS on Exit Relays

Unlike other types of relays, exit relays also do DNS resolution for Tor clients. DNS resolution on exit relays is crucial for Tor clients and it should be reliable and fast by using caching.

  • DNS resolution can have a significant impact on the performance and reliability that your exit relay provides.
  • Don't use any of the big DNS resolvers (Google, OpenDNS, Quad9, Cloudflare, 4.2.2.1-6) as your primary or fallback DNS resolver to avoid centralization.
  • We recommend running a local caching and DNSSEC-validating resolver without using any forwarders (specific instructions follow below, for various operating systems).
    • If you want to add a second DNS resolver as a fallback to your /etc/resolv.conf configuration, choose a resolver within your autonomous system and make sure that it is not your first entry in that file (the first entry should be your local resolver).
    • If a local resolver like unbound is not an option for you, use a resolver that your provider runs in the same autonomous system (to find out if an IP address is in the same AS as your relay, you can look it up using bgp.he.net).
  • Avoid adding more than two resolvers to your /etc/resolv.conf file to limit AS-level exposure of DNS queries.

There are multiple options for DNS server software. Unbound has become a popular one but feel free to use any other software that you are comfortable with. When choosing your DNS resolver software, make sure that it supports DNSSEC validation and QNAME minimization (RFC7816). Install the resolver software over your operating system's package manager, to ensure that it is updated automatically.

By using your own DNS resolver, you are less vulnerable to DNS-based censorship that your upstream resolver might impose.

Below are instructions on how to install and configure unbound – a DNSSEC-validating and caching resolver – on your exit relay. Unbound has many configuration and tuning knobs but we keep these instructions simple and short; the basic setup will do just fine for most operators.

After switching to unbound, verify it works as expected by resolving a valid hostname. If it does not work, you can restore your old resolv.conf file.

Debian/Ubuntu

The following three commands install unbound, backup your DNS configuration, and tell the system to use the local unbound:

apt install unbound
cp /etc/resolv.conf /etc/resolv.conf.backup
echo nameserver 127.0.0.1 > /etc/resolv.conf

To avoid that the configuration gets changed (for example by the DHCP client):

chattr +i /etc/resolv.conf

The Debian configuration ships with QNAME minimization (RFC7816) enabled by default, so you don't need to enable it explicitly. The unbound resolver you just installed also does DNSSEC validation.

CentOS/RHEL

Install the unbound package:

yum install unbound

in /etc/unbound/unbound.conf replace the line

# qname-minimisation: no

with:

qname-minimisation: yes

enable and start unbound:

systemctl enable unbound
systemctl start unbound

Tell the system to use the local unbound server:

cp /etc/resolv.conf /etc/resolv.conf.backup
echo nameserver 127.0.0.1 > /etc/resolv.conf

To avoid that the configuration gets changed (for example by the DHCP client):

chattr +i /etc/resolv.conf

FreeBSD

FreeBSD ships unbound in the base system but the one in ports is usually following upstream more closely, so we install the unbound package:

pkg install unbound

Replace the content in /usr/local/etc/unbound/unbound.conf with the following lines:

server:
    verbosity: 1
    qname-minimisation: yes

enable and start the unbound service:

sysrc unbound_enable=YES
service unbound start

Tell the system to use the local unbound server:

cp /etc/resolv.conf /etc/resolv.conf.backup
echo nameserver 127.0.0.1 > /etc/resolv.conf

To avoid that the configuration gets changed (for example by the DHCP client):

chflags schg /etc/resolv.conf