why master need few days to pass a new DNS entry to secondary?

[Julie Xu]

I have a strange problem that is if I add a DNS entry in primary DNS
server, the secondary have to get it on next day (sometime few days). And
this is not happend
for every time we add a dns name in, sometime, it is fine!

I think there is a problem somewhere, but, there is no log errors, no any
information
I can trace on. 

Could anyone advice me what way I can go to find the problem? 

Any comments will be appreciated

Thanks in advance


Julie Xu

Unix/Network Administrator
Information Techonology Directorate
University of Westen Sydney, Campbelltown
Campbelltown NSW 2560

Phone: 61 02 4620-3098
Mobile: 0416 179 868
Email: j.xu at uws.edu.au