DNS Measurement, Troubleshooting and Security Auditing Toolset
Ever been wondering if your ISP is hijacking your DNS traffic? Ever observed any misbehavior with your DNS responses? Ever been redirected to wrong address and suspected something is wrong with your DNS? Here we have a set of tools to perform basic audits on your DNS requests and responses to make sure your DNS is working as you expect.
You can measure the response time of any given DNS server for arbitrary requests
using dnsping. Just like traditional ping utility, it gives you similar
functionality for DNS requests.
You can also trace the path your DNS request takes to destination to make sure
it is not being redirected or hijacked. This can be done by comparing different
DNS queries being sent to the same DNS server using dnstraceroute and observe
if there is any difference between the path.
dnseval evaluates multiple DNS resolvers and helps you choose the best DNS
server for your network. While it is highly recommended using your own DNS
resolver and never trust any third-party DNS server, but in case you need to
choose the best DNS forwarder for your network, dnseval lets you compare
different DNS servers from performance (latency) and reliability (loss) point
of view.
Installation
There are several ways that you can use this toolset. However, using the source code is always recommended.
Source Code
- Check out the git repository and install dependencies:
git clone https://github.com/farrokhi/dnsdiag.git
cd dnsdiag
pip3 install -r requirements.txt
- You can alternatively install the package using pip:
pip3 install dnsdiag
Binary Package
From time to time, binary packages will be released for Windows, Mac OS X and Linux. You can grab the latest release from releases page.
Docker
If you don't want to install dnsdiags on your local machine, you may use the docker image and run programs in a container. For example:
docker run --network host -it --rm farrokhi/dnsdiag dnsping.py
dnsping
dnsping pings a DNS resolver by sending an arbitrary DNS query for given number of times.
A complete explanation of supported command line flags is shown by using --help. Here are a few useful flags:
- Using
--tcp,--tlsand--dohto select transport protocol. Default is UDP. - Using
--flagsto display response flags for each response - Using
--dnssecto request DNSSEC if available
In addition to UDP, you can ping using TCP, DoT (DNS over TLS) and DoH (DNS over HTTPS) using --tcp, --tls and --doh respectively.
./dnsping.py -c 5 --dnssec --flags --tls -t AAAA -s 9.9.9.9 ripe.netdnsping.py DNS: 9.9.9.9:853, hostname: ripe.net, proto: TLS, rdatatype: AAAA, flags: RD
169 bytes from 9.9.9.9: seq=1 time=279.805 ms [QR RD RA AD] NOERROR
169 bytes from 9.9.9.9: seq=2 time=107.237 ms [QR RD RA AD] NOERROR
169 bytes from 9.9.9.9: seq=3 time=96.747 ms [QR RD RA AD] NOERROR
169 bytes from 9.9.9.9: seq=4 time=107.782 ms [QR RD RA AD] NOERROR
169 bytes from 9.9.9.9: seq=5 time=94.713 ms [QR RD RA AD] NOERROR
--- 9.9.9.9 dnsping statistics ---
5 requests transmitted, 5 responses received, 0% lost
min=94.713 ms, avg=137.257 ms, max=279.805 ms, stddev=79.908 ms
It also displays statistics such as minimum, maximum and average response time as well as jitter (stddev) and lost packets.
There are several interesting use cases for dnsping, including:
- Comparing response times using different transport protocols (e.g. UDP vs DoH)
- Measuring how reliable your DNS server is, by measuring Jitter and packet loss
- Measuring responses times when DNSSEC is enabled using
--dnssec
dnstraceroute
dnstraceroute is a traceroute utility to figure out the path that your DNS request is passing through to get to its destination. You may want to compare it to your actual network traceroute and make sure your DNS traffic is not routed to any unwanted path.
In addition to UDP, it also supports TCP as transport protocol, using --tcp flag.
./dnstraceroute.py --expert --asn -C -t A -s 8.8.4.4 facebook.comdnstraceroute.py DNS: 8.8.4.4:53, hostname: facebook.com, rdatatype: A
1 192.168.0.1 (192.168.0.1) 1 ms
2 192.168.28.177 (192.168.28.177) 4 ms
3 192.168.0.1 (192.168.0.1) 693 ms
4 172.19.4.17 (172.19.4.17) 3 ms
5 dns.google (8.8.4.4) [AS15169 GOOGLE, US] 8 ms
=== Expert Hints ===
[*] public DNS server is next to a private IP address (possible hijacking)
Using --expert will instruct dnstraceroute to print expert hints (such as
warnings of possible DNS traffic hijacking).
dnseval
dnseval is a bulk ping utility that sends an arbitrary DNS query to a give list of DNS servers. This script is meant for comparing response time of multiple DNS servers at once.
You can use dnseval to compare response times using different transport
protocols such as UDP (default), TCP, DoT and DoH using --tcp, --tls and
--doh respectively.
./dnseval.py --dnssec -t AAAA -f public-servers.txt -c10 ripe.netserver avg(ms) min(ms) max(ms) stddev(ms) lost(%) ttl flags response
----------------------------------------------------------------------------------------------------------------------------
1.0.0.1 36.906 7.612 152.866 50.672 %0 300 QR -- -- RD RA AD -- NOERROR
1.1.1.1 7.752 7.512 8.132 0.183 %0 298 QR -- -- RD RA AD -- NOERROR
2606:4700:4700::1001 7.661 7.169 8.102 0.240 %0 297 QR -- -- RD RA AD -- NOERROR
2606:4700:4700::1111 7.802 7.000 8.128 0.312 %0 296 QR -- -- RD RA AD -- NOERROR
195.46.39.39 14.723 7.024 78.239 22.362 %0 300 QR -- -- RD RA -- -- NOERROR
195.46.39.40 7.524 6.972 10.897 1.191 %0 300 QR -- -- RD RA -- -- NOERROR
208.67.220.220 70.519 6.694 180.229 66.516 %0 300 QR -- -- RD RA AD -- NOERROR
208.67.222.222 37.868 6.663 107.601 41.178 %0 300 QR -- -- RD RA AD -- NOERROR
2620:0:ccc::2 31.471 6.768 178.647 56.546 %0 299 QR -- -- RD RA AD -- NOERROR
2620:0:ccd::2 20.651 6.699 145.029 43.702 %0 300 QR -- -- RD RA AD -- NOERROR
216.146.35.35 19.338 6.713 131.198 39.306 %0 300 QR -- -- RD RA AD -- NOERROR
216.146.36.36 107.741 73.421 266.969 58.003 %0 299 QR -- -- RD RA AD -- NOERROR
209.244.0.3 14.717 7.015 80.329 23.058 %0 300 QR -- -- RD RA -- -- NOERROR
209.244.0.4 7.184 7.003 8.197 0.361 %0 300 QR -- -- RD RA -- -- NOERROR
4.2.2.1 7.040 6.994 7.171 0.052 %0 299 QR -- -- RD RA -- -- NOERROR
4.2.2.2 14.358 6.968 79.964 23.052 %0 300 QR -- -- RD RA -- -- NOERROR
4.2.2.3 7.083 6.945 7.265 0.091 %0 299 QR -- -- RD RA -- -- NOERROR
4.2.2.4 7.103 6.990 7.238 0.086 %0 299 QR -- -- RD RA -- -- NOERROR
4.2.2.5 7.100 7.025 7.267 0.074 %0 299 QR -- -- RD RA -- -- NOERROR
80.80.80.80 149.924 53.310 247.395 97.311 %0 299 QR -- -- RD RA AD -- NOERROR
80.80.81.81 144.262 53.360 252.564 97.759 %0 298 QR -- -- RD RA AD -- NOERROR
8.8.4.4 9.196 7.160 10.974 1.484 %0 299 QR -- -- RD RA AD -- NOERROR
8.8.8.8 7.847 7.056 9.866 0.836 %0 299 QR -- -- RD RA AD -- NOERROR
2001:4860:4860::8844 31.819 7.194 155.761 50.671 %0 299 QR -- -- RD RA AD -- NOERROR
2001:4860:4860::8888 7.773 7.200 9.814 0.777 %0 298 QR -- -- RD RA AD -- NOERROR
9.9.9.9 21.894 6.670 81.434 30.299 %0 300 QR -- -- RD RA AD -- NOERROR
2620:fe::fe 21.177 6.723 80.046 30.062 %0 300 QR -- -- RD RA AD -- NOERROR
Author
Babak Farrokhi
- github: github.com/farrokhi
- website: farrokhi.net
- mastodon: @[email protected]
- twitter: @farrokhi
License
dnsdiag is released under a 2 clause BSD license.