I've got a DES-1210-28P switch here. I know this isn't the forum for it, but there is no forum for it, so this is good enough. The 1228P is pretty similar. Probably the exact same hardware.
I reported this to DLink already. They don't seem very interested.
The SNMP MIB says that a certain OID will reset/reboot the system. However, I've found that it actually resets the system and CLEARS THE CONFIG. Obviously, that's really bad.
Here's the example command as run from a Linux system;
snmpset -v2c -c private 1.2.3.4 SNMPv2-SMI::enterprises.171.10.75.6.4.2.0 i 1
Where private is the community name and 1.2.3.4 is the IP address.
The MIB says that this OID is supposed to reset the system, but nothing about the configuration.
Note that SNMP is not enabled by default. However, if you turn it on, the "private" community name has full RW access by default. Since the community configuration is on another page, it's very possible to overlook this.