mbooth,
Greetings. First, let me point out that I'm pretty new here... But, I'm gonna jump in anyhow. (Even so, I'd suggest you wait for a couple of more experienced DNS-323 users to come in and follow-up.)
Based on what you said, I have a couple of thoughts...
1. Since your NAS is shutting down ports on your router, it's NIC port is probably "spewing" and the router is smart enough to shut it down. (I am assuming the router ports you referenced above are coming back after a reset?)
2. If (since) you can't get to your NAS admin utility, then you're gonna have to do a hard reset on the NAS (via the little pin-hole button on the back). NOTE: This is not supposed to affect the data on your HDD(s)... just reset the NAS to factory defaults. I suggest you A) first, unplug the NIC cable, B) then, press and hold the factory reset button and wait for it to do it's thing. After that, you may want to shut it down, unplug the PWR CBL, wait a minute, and back on... two times...
before you plug the NIC cable back in and try to get into the admin utility.
If your router's port shutdown problem goes away, then you lucked up.

If the NAS is still shutting down the router's ports, then you probably got spiked.
