- Technical Guides
- Latency Optimised DNS Resolvers (KB15060204)
Latency Optimised DNS Resolvers
Vorboss provides a number of recursive DNS resolvers for our clients. These servers are diversely located for improved reliability and resilience, but it’s essential that you always specify servers from more than one site.
In order that your systems have the optimal DNS performance, we recommend specifying DNS servers based on their round-trip latency within our network.
To achieve this, we have provided a script which dynamically loads the Vorboss DNS resolver list, checks the round-trip time to each server and then loads them into your
/etc/resolv.conf file in order of lowest latency.
To run this script, simply execute the following snippet:
# Set the DNS resolvers SCR=config-resolvers.sh && wget -q http://mirror.vorboss.net/$SCR && chmod +x $SCR && ./$SCR && rm $SCR;
What It Does
This tool will update your
resolv.conf to look similar to this:
# Generated from list of resolvers using resolvers.vorboss.net on Wed Apr 24 20:36:19 BST 2013. # The list of resolvers was sorted by measured network latency. nameserver 220.127.116.11 # Measured latency: 0.47ms nameserver 18.104.22.168 # Measured latency: 0.47ms nameserver 22.214.171.124 # Measured latency: 0.48ms nameserver 126.96.36.199 # Measured latency: 0.74ms
How It Works
The script is seeded with our authoritative name servers, from which it performs a lookup to
resolvers.vorboss.net. This is a special A record which will return a list of valid DNS recursive resolvers on our network.
Next, the script runs an
fping to each server, sorts the output and inserts this into your