DNS cache time

How can you determine the dns cache time

[javaworld]

How can you determine the dns cache time for a particular dns server? I have a domain I had transferred to another hosting company on the 8th of this past week. The propogation has gone around the world pretty much except for the dns servers at the company I get my broadband throgh. If I knew their name servers, is there any test I could run to determine how often those name servers refresh? I've emailed them about this issue.

[py9jmas]

DNS does not propagate around the world. The only progagation is from the primary DNS servers to the handful of secondary DNS servers. The majority of the waiting time is for cached resorce records (including negatively cached records) to expire. Once the records have expired the updated information is requested from the parent DNS server. The expiry times are defined in the SOA (Start of Authority) section of the zone file file. What values did you use in the SOA?

I expect the reason your ISP's DNS server is showing old results is that your requests prior to the changes lead to the resource records being cached. When you check another random DNS server they have no RRs cached for your zone so request fresh data.

[SkyDog]

It depends on how often your ISP updates their DNS. You can test your ISPs nameservers by doing an nslookup and setting the name server to their server name ie >server ns.myisp.com. If you're on windows, I don't think they have an nslookup, you could ping or tracert from the DOS prompt and see what address your ISP is directing you to.

[javaworld]

Thanks for your post. I called my high speed internet company and we figured out that of the dns servers listed in my computer for them, the one was resolving the correct ip address of the new site but the other one was not so they said they would put a request through to update it. They said that normally the servers take 7 days to update with changes.