> I forget to say the problem is obvious in computer classroom.
> Using M0N0 translate 100 computers in computer classroom, they
> will boot at the same time. Then students surf Internet.
> About 10%-15% computer has DNS problem.This bother me and
> students.Maybe too many computers request DNS service at the same
> time.I will try set DNS to M0N0 Lan IP.
This really doesn't sound like a m0n0wall issue at all. It sounds
like your ISP's DNS server is flaky. If you have some other internal
DNS servers you can use (not m0n0wall, since it only caches responses
it receives from your ISP's DNS servers), try those and see what
> Can I modify kernel parameters(sysctl) or NAT rules or Firewall
> rules or recompile Kernel to reduce this problem?