Router/Switch weirdness

[NiX]

This is the weirdest thing I've had happen so far from this router. I've had intermittent problems with it in terms of Wireless connectivity, but never with it acting as a switch. It's a D-Link (I know, crap. It was free.) DI-514 Rev. B1. It's pretty damn old and not very reliable, but like I said, it's never had a problem when acting as a switch and not a router. I recently hooked it back up after coming back from my trip home and now it's dropping connection every 5-10 minutes. I tried disabling wireless mode and nothing happened. Google turned up nothing for me in terms of the same issue. I think that's because most people don't use their router as a switch.

So, quick rundown: It drops connection to everything (don't know if it's IP, DNS or whatever) and sometimes comes back instantaneously or after 5-10 minutes. This DIDN'T happen before.

Only guess I've come up with that still hasn't produced results: DHCP conflict between my router and the router that's actually giving the internet.

[Trippy]

Assuming it's not just a hardware failure (maybe the physical port is flaky now, try another one) I would guess that something is filling up its memory or a lookup table and causing it to lock up. On my crappy ADSL router I can't run things like GameSpy unless I limit the number of simulateous connections cause the NAT address mapping part can't keep up with all the return replies and causes it to lock up. Now the switch part doesn't need a NAT mapping table but it does have a table to keep track of MAC addresses and which port is used by which MAC address and that sort of thing.

So something about your network may have changed that's causing a device to send out packets that are overflowing something on the switch. If I was being paranoid I would say it was a trojan/worm that is either intentionally MAC flooding or ARP spoofing your switch to try and sniff all the traffic going through the switch or it's "pinging" a large number of IPs to try and map out your internal LAN.

[NiX]

Per chance could the mass ping issue come from someone else's computer on the network and still cause my switch to lock up?

[Trippy]

Per chance could the mass ping issue come from someone else's computer on the network and still cause my switch to lock up?

Yes.