Rejoice. Google announces a public DNS offering that we can use for testing when deploying Internet connections, or troubleshooting proxy servers.
Greg-Ferros-MacBook-Pro:~ gregferro$ dig @188.8.131.52 etherealmind.com
; < <>> DiG 9.6.0-APPLE-P2 < <>> @184.108.40.206 etherealmind.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER< <- opcode: QUERY, status: NOERROR, id: 6418 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;etherealmind.com. IN A ;; ANSWER SECTION: etherealmind.com. 300 IN A 220.127.116.11 ;; Query time: 594 msec ;; SERVER: 18.104.22.168#53(22.214.171.124) ;; WHEN: Thu Dec 3 19:50:18 2009 ;; MSG SIZE rcvd: 50 Greg-Ferros-MacBook-Pro:~ gregferro$
Testing your Internet connection using ICMP
Also, both of these IP addresses respond to ICMP so if you need to test your Internet connection you can easily remember to type
The engineers have clearly chosen easy to remember IP addresses so that all Network Engineers can rejoice at this most useful, most ordinary of tools. It’s so simple, so elegant. An engineer must have thought of it.
SLA Monitors for Internet connectivity
Many people uses IOS SLA monitors to test for Internet connectivty. It’s always been difficult to know what to test that is reliable measure of application availability. The Google Public DNS is a good choice to poll when using these monitors.
What is Google Public DNS?
Google Public DNS is a free, global Domain Name System (DNS) resolution service, that you can use as an alternative to your current DNS provider.
To try it out:
* Configure your network settings to use the IP addresses 126.96.36.199 and 188.8.131.52 as your DNS servers