I have just uploaded a new package onto Check_MK Exchange. The package contains 2 checks for DELL N1500, N2000 and N3000 series switches. They check CPU utilization and RAM usage using SNMP requests. The checks have been created under 1.2.6 version of Check_MK and support this version.
After a verification by Check_MK staff the package can be downloaded from Check_MK Exchange web site.