I am trying to figure out why my Santa Cruz mountains Surfnet WISP setup takes so long to load a web page (even Google's bare bones home page takes, sometimes far too long) so I'm trying to better understand how DNS servers work.
What I have in my wrt54g home router is a set of three supposedly fast DNS servers from this DNS server list:
I keep getting intermittent "Microtik hotspot errors" from Surfnet ... and their (rather grouchy) technical support blamed my DNS servers setup.
I can't prove or disprove that until/unless I better understand DNS servers, overall, and how they impact speed of loading (or not loading) web pages.
Is 'this' what happens?
- I type formatting linkin my laptop browser on PC 10.20.30.1
- That "formatting link" request goes wirelessly to my office wrt54g router which is 10.20.30.40
THIS IS THE PART THAT I 'THINK' I UNDERSTAND ...
- The office wrt54g router sends that "formatting link" request to the rooftop ubuquiti radio which is 192.168.10.20 but the office wrt54g router must also be sending its DNS server list to the bridge (right?) a) wrt54g DNS1 = 8.8.8.8 b) wrt54g DNS2 = 8.8.4.4 c) wrt54g DNS3 = 4.2.2.1 d) wrt54g WINS = blank
What command can I use to 'see' that DNS transaction?
- My rooftop ubiquiti radio sends the "formatting link" request & DNS list to my rooftop antenna which sends it through the air to the Surfnet line-of-sight antenna on 192.168.4.1
THIS IS THE PART I REALLY DON'T UNDERSTAND.
- Surfnet sees that request for "formatting link" and the list of three DNS servers (I guess), and it forwards that "formatting link" request to the first of those DNS servers (I guess) which is 8.8.8.8.
- The DNS server at 8.8.8.8 presumably forwards back the IP address of "formatting link" (e.g., 74.125.224.112) but a "tracerouteformatting link" on Ubuntu doesn't seem to show any of that).
HOW DO I CHECK HOW LONG THE DNS SERVER IS TAKING TO RESPOND?
Here is a traceroute:
$ traceroute
Obviously I'm confused but I'm trying to debug why web pages, intermittently, take far too long to load (and one out of fifty fail outright, giving a Microtik hotspot error, 192.168.4.1).
Is there a command that shows what is happening at the DNS server level?