After running for a month or so the svchost.exe that contains the DHCP as well as DNSCache services is showing a Mem Usage of above 400M in task manager. My network interfaces are all static IPs and not running a DHCP server so I'm guessing the usage is from the DNSCache.
Is there any reason that the memory usage for this process should be so high? I still have over a gig of free memory but I don't want to be worrying that if I need a lot of RAM at short notice (which does happen on these servers), that I'll run out. Maybe svchost is smart enough to give memory back under pressure but should I count on that?
ipconfig /displaydns the cache itself only has around 64 entries so it can't possibly need all that RAM can it?
Edit: I wanted to add a note that while the below answer is useful, it did not fix my problem. My problem is specific to either the DNSCache (dns client) or DHCP (dhcp client) services. The below hotfix is for DNS Server memory leak.