Macs, Dns & Dhcp Troubles.


To whom it may concern:

I'm a network administrator with a very strange problem. I've got a mixed network (Wintel & Mac), I just put in a T1 line and everything suddenly went south on the Macs.

Here's the issue:

1. I can hook my DSL line back up, use my linksys router with DHCP enabled and all is great.
2. I unhooked my DSL, hooked the same router to my cisco 1751 (my ISP is providing a DHCP address currently). Now none of the Macs get a DNS server. I've hard coded the DNS server on one eMac and that appears to have fixed the problem, but my Mac Laptops (wireless or wired) will NOT get the DNS, even if I hard code it in the network settings.

So my question is this: why would this happen? All the Wintel machines running XP Pro SP2 work fine.

I've gone out and purchased a new router (a netgear router) thinking that the Linksys had a bug, but I'm having the same issues.

I've been pulling my hair out since I made this transition.

Some other info: The ISP is NOT providing any NAT, my internal network does the NAT. I have tried having my ISP use a Static IP address (which was the first time I found the problem, I thought by getting them to setup a DHCP address may solve the problem, but it didn't).

Anyway, I'm pulling my hair out about this, I've searched google (to no avail) and other Mac forums with no luck.

Any help would be appreciated.




I figured this one out after several days of pulling out my hair. Just so you all know (should you get put in the same situation), here's the scoop:

1. My ISP's primary DNS server was setup to allow guests to do DNS lookups, but only about 10 a day.
2. All my Mac OSX Machines (wireless, wired, laptop, desktop) had the same issues.

Basically, it appears to me as though OSX has an issue with DNS. If the primary DNS server exists, but doesn't respond, it apparently doesn't change over to the secondary DNS. Once my ISP put our network address into the primary DNS servers list of allowed networks, all my problems were fixed. But it was like pulling teeth to get the ISP to admit to this issue.

Thanks for taking the time to look at this post.