DNS ping timer

dns_pinger.rb

#simple script to check the ping times of various DNS servers

results = Hash.new
dns_servers = %w(4.2.2.1
4.2.2.2
4.2.2.3
4.2.2.4
4.2.2.5
4.2.2.6
68.94.156.1
68.94.157.1
204.117.214.10
199.2.252.10
204.97.212.10
208.67.222.222
208.67.220.220
216.234.234.30
12.96.160.115
216.39.90.2
216.39.90.3
72.36.190.2
72.36.191.2
66.215.64.14
24.205.1.14
192.168.4.1
)
command = "ping -c 3"
puts "#{command}\n"
printf "%-16s %-6s\n", "Server", "Average Latency"
puts "--------------------------------------"
dns_servers.each do |d| 
  output = `#{command} #{d}`
  results[d.to_s] = output.split("\/")[-3].to_f
  printf "%-16s %.2f\n", d, results[d.to_s]
end

puts "\n---  Sorted Results ---"
results.sort{|a,b| a[1]<=>b[1]}.each { |elem|
  printf "%-16s %.2f\n", elem[0], elem[1]
}


#  Commented DNS server list:
# 4.2.2.1
# 4.2.2.2
# 4.2.2.3
# 4.2.2.4
# 4.2.2.5
# 4.2.2.6
# These are all DNS server addresses that resolve differently across the country. Some are GTE, some Level3, some Verizon, but are all VERY speedy and work well. Some also reccomend using the ORSC’s public servers, one of which is 199.166.24.253. I have not used this server, but others say it is fast.
# 
# SpeakEasy Nameservers
# 66.93.87.2
# 216.231.41.2
# 216.254.95.2
# 64.81.45.2
# 64.81.111.2
# 64.81.127.2
# 64.81.79.2
# 64.81.159.2
# 66.92.64.2
# 66.92.224.2
# 66.92.159.2
# 64.81.79.2
# 64.81.159.2
# 64.81.127.2
# 64.81.45.2
# 216.27.175.2
# 66.92.159.2
# 66.93.87.2
# 
# ORSC Public Access DNS Nameservers
# 199.166.24.253
# 199.166.27.253
# 199.166.28.10
# 199.166.29.3
# 199.166.31.3
# 195.117.6.25
# 204.57.55.100
# 
# Sprintlink General DNS
# 204.117.214.10
# 199.2.252.10
# 204.97.212.10
# 
# Cisco
# 128.107.241.185
# 192.135.250.69