Network. Computer sending weird packets etc.

[join993]

Hello. We've been having issues here at home with our network for some time. We've tried many different routers, and now we're tierd of it and decided to get to the bottom of the issue.

Now, after looking in the logs, we found out that there is a computer that's sending around all kinds of different packets etc, the latest being netBIOS'. I think this is why the router randomly shuts all of us out of the network, these netBIOS' get sent around nearly all the time, sometimes with up to 3 in 1 second. Now, after just having a quick look at the problem, what we can make of the logs, it's a mac computer sending out all these packets and whatnot. Is this not weird? The person using this mac is careful about what he downloads, so to get spyware/maleware/whatever like this is VERY unlikely.

Not sure how all the other people on the network uses their computer, but I know that more than one of them are careless and will download pretty much anything.

Anyone had the same kind of issue? Can someone help? I'd prefer if we don't have to reformat most computers, but if we have to we'll do it.

EDIT: I can post some screenshots of the logs, if anyone wants a better idea of what I mean.

 

[Neodude1123201]

Some Screenshots would be helpful. Have you ran an Antivirus on the PC's?

 

[join993]

Okay, here are some logs.

I've come so far with the netBIOS packets so that I know that it's being sent from the mac in the house, to my xbox 360. The 192.168.137.1 is my xbox, in the first log 192.168.1.34 is the mac. Since the router change IP adresses when you connect again I had to compare MAC adresses in the second log, but I think that 192.168.1.33 in the second log is the mac again.

I've also been getting this from time to time.

32 02/09/2010 21:43:47 Packet without a NAT table entry blocked: ICMP(type:5, code:1) 80.250.51.71 213.64.51.239 ACCESS BLOCK

Both are IPs from around Hollad or something. No idea why they are in my router.

Is there even a need for anti virus on a mac? I think that the other computers have anti-virus, but you never know, we've had some run-ins with spy-ware that really screwed up our internet, so you'd think they would've learned to use it anyway.

I've been talking to some other fellas on some other forums but none really seem to know what's really going on with my network

 

[jmacavali]

I'd definately scan all the computers. I'd use MalwareBytes AntiMalware. It's the best at finding spyware/adware. If it comes back clean or doesn't find anything then you could try a scan with AVG Free and see if it finds a virus of any kind. I'd do it on all of them. To the best of my knowledge about MAC's is that they are not Virus/spyware-proof, just very unlikely to get them. See if you take the MAC off the network and keep it off for a few days and see if it gets any better. Then you'll know if it is the MAC or not causing the issue.