DNS Rookie Question

[FuLL_MeT4L]

Hi all,

My office has two internet connections. One being a 10mb uncapped ADSL line and the other being a wireless solution for redundancy.
The latter is extremely expensive and requires that we use their DNS servers. I assume that these DNS setups should actually be present in the CISCO configuration attached to the wireless solution but for whatever reason they're not.

So my question is: if a computer is set up with these DNS servers (so that it has access via the wireless solution if needed), but is actually using the mweb ADSL connection, what happens? Will the wireless solution say "hey you're using our servers, lets bill you!" (might they think we're using their connection when we're not?). What sort of traffic does a DNS server actually use? I'd always assumed that it's quite minimal.

Thanks in advance!

 

[EviLMasH]

Im guessing you have a router that determines if your ADSL is offline before routing your traffic via the wireless. If so, as long as you set your primary DNS to your ADSL provider, and your secondary to your wireless, you should only use the wireless dns when your adsl dns is unreachable (depending on how your routing is set up).
What i would recommend though, is setting up a router as a dns relay, which can switch between your adsl and wireless dns, depending on which one is active. then just set up all the computers to use the router as a dns.

 

[w1z4rd]

I have a quick and dirty way of dealing with this. I change my DNS servers to 8.8.8.8 (Googles DNS). As I have one line that uses Telkom and one that uses Internet Solutions. So to stop DNS problems with the main line fails I changed them to public DNS

 

[Tinuva]

Said wireless ISP probably prevent users from using other DNS servers, would be really lame but thats what it sounds like. I would switch to another if possible.

 

[daffy]

Said wireless ISP probably prevent users from using other DNS servers, would be really lame but thats what it sounds like. I would switch to another if possible.

Blocking access to your recursive DNS servers from non-customers is actually a best current practice. If you have any security knowledge, you'd understand why. http://www.cisco.com/web/about/security/intelligence/dns-bcp.html#3 for some motivation.

There's nothing stopping you from running up your own recursive DNS server, or using a public DNS service such as Google DNS or OpenDNS.

 

[Tinuva]

Blocking access to your recursive DNS servers from non-customers is actually a best current practice. If you have any security knowledge, you'd understand why. http://www.cisco.com/web/about/security/intelligence/dns-bcp.html#3 for some motivation.

There's nothing stopping you from running up your own recursive DNS server, or using a public DNS service such as Google DNS or OpenDNS.

I think you misunderstood what I said.

1st, I don't disagree with what you are saying, that is best practice. This is almost a given nowadays.

Now, it sounds like the WISP in question, might be blocking their users from use any other DNS server other than their own, ie. ISP block their own users from using lets say google dns. Maybe I just wasn't clear, but if that is the case, that would be lame.
There is also the odd chance that I read something from the OP which isn't what it is saying.

 

[FuLL_MeT4L]

Well I tested it with Google's DNS this afternoon and it worked fine! So this might indeed be a viable solution.

What would be the disadvantages of using Google's DNS. And what advantages might be had from using the ISP's DNS?