-3

When I used nslookup to query google.com twice, I got same ip addresses but different order, why? These are return: Server: 129.173.1.100 Address: 129.173.1.100#53

Non-authoritative answer:
Name:   google.com
Address: 74.125.226.169
Name:   google.com
Address: 74.125.226.174
Name:   google.com
Address: 74.125.226.160
Name:   google.com
Address: 74.125.226.161
Name:   google.com
Address: 74.125.226.162
Name:       google.com
Address: 74.125.226.163
Name:   google.com
Address: 74.125.226.164
Name:   google.com
Address: 74.125.226.165
Name:   google.com
Address: 74.125.226.166
Name:   google.com
Address: 74.125.226.167
Name:   google.com
Address: 74.125.226.168

second time:

Server:     129.173.1.100
Address:    129.173.1.100#53

Non-authoritative answer:
Name:   google.com
Address: 74.125.226.167
Name:   google.com
Address: 74.125.226.168
Name:   google.com
Address: 74.125.226.169
Name:   google.com
Address: 74.125.226.174
Name:   google.com
Address: 74.125.226.160
Name:   google.com
Address: 74.125.226.161
Name:   google.com
Address: 74.125.226.162
Name:   google.com
Address: 74.125.226.163
Name:   google.com
Address: 74.125.226.164
Name:   google.com
Address: 74.125.226.165
Name:   google.com
Address: 74.125.226.166

Any reply will be really appreciated!!!

2
  • 3
    Round Robin DNS for load balancing. That is DNS 101 for beginners - and as such a question that should not be asked here.
    – TomTom
    Mar 11, 2014 at 17:14
  • Sorry, I did search this but not detailed explanation shown Mar 13, 2014 at 14:05

1 Answer 1

1

When you consider the main purpose of having multiple A records for a single name (ie:DNS Round Robin) is for load balancing purposes, it would make sense that the way most DNS servers will implement this is by rotating the records that are returned. Most applications will use the first record that is returned (even when multiple records are returned), so rotating the records basically preforms a round-robin load balancing function.

0

Not the answer you're looking for? Browse other questions tagged .