Dns Server has a limitaion?

Still setting Plb 305 with diskless boot.
WAN1 WAN2 Wan3 are not in drop in mode.
But when certain number of clients over no internet look like i can ping google but no internet look like DNS issue.
My question is on LAN side are there limit to DNS look up. if so how do i resolve this?

I used google/open dns/isp dns/ all the same I think over certain number no more it is what it should be?
I need to boot 50 computer on lan…lol
Please help me on this.
Thank you…


We have no restriction on the DNS resolving. Believe you having problem on your setting or your ISP. Please open ticket for us to check further.