Internet connection drops repeatedly. am i under attacked (viruses/hackers)?

Question

our internet connection drops repeatedly for the past days. should i block udp port 137 and 138 from my firewall? i got some of my netgear firewall router(fvs338) logs below. how can sort this out? please help. thanks in advance.


Sep 11 11:34:04 [FVS338] [kernel] LOG_PACKET IN=SELF OUT=LAN SRC=192.168.0.253 DST=192.168.0.250 PROTO=ICMP TYPE=3 CODE=3
- Last output repeated 34 times -
Sep 11 11:34:05 [FVS338] [kernel] LOG_PACKET IN=SELF OUT=WAN SRC=127.0.0.1 DST=127.0.0.1 PROTO=TCP SPT=1666 DPT=7911
- Last output repeated twice -
Sep 11 15:24:55 [FVS338] [kernel] LOG_PACKET IN=SELF OUT=WAN SRC=127.0.0.1 DST=127.0.0.1 PROTO=TCP SPT=7911 DPT=2251
Sep 11 15:24:55 [FVS338] [kernel] LOG_PACKET IN=SELF OUT=WAN SRC=127.0.0.1 DST=127.0.0.1 PROTO=TCP SPT=2251 DPT=7911
Sep 11 15:25:01 [FVS338] [kernel] LOG_PACKET IN=LAN OUT=SELF SRC=192.168.0.56 DST=192.168.0.255 PROTO=UDP SPT=137 DPT=137
- Last output repeated 7 times -

Answer 1

Xp or Vista? try zonealrm free edition ..it should help you see what's going on here..good luck

Answer 2

ummmmmm



Well, first of all port 137, 138 are for NETBIOS and they usually are a good idea to block. If you do not need NETBIOS then it should be blocked as it is a common attack vector.



As for the stuff you have pasted... 127.0.0.1 is the loopback address.. localhost.. .or for lack of better term "you"...

192.168.*.* are also private IP addresses that for instance your router would assign you.



You can go to the IANA site to see what commonly used ports are:

http://www.iana.org/assignments/port-numbers

IANA is who decides what ports are used for what...



You could use a program like fport to see what programs are trying to use what ports. It is a little better than netstat (included with windows) because it will give you more details.



I do not see any outside traffic from what you have pasted... if you were under attack I would expect to see many hits from an external IP address, flooding you, for instance.



Check with your ISP too.. there may be a problem in the area.



Have you installed anything lately that may be the cause.



While I do not see anything really strange about the output it doesn't look exactly normal either but it looks like an internal issue.





I would need more info to speculate further.



Good luck.

Answer 3

Its hard to tell , but it seems to be NOT that your router is losing contact, but more along the lines of your computer is disconnecting from the router.



I would make sure you have up-to-date drivers for your reciever.



Then try to get a firewall, such as ZoneAlarm (free).

Once you get ZA, turn off Windows Firewall and any other firewall you may have. Keep your computer on for a while, and see if you still lose connection.



Then get some sort of virus scanner, such as AVG Free Edition 2007 (free). Do a full scan, delete any bad entries, then see if you stay connected for a while.



Try a spyware/adware scanner, such as Ad-Aware 2007 (free, full version costs money). I doubt that spyware is the source, but you never know.



Try to get a different browser, such as Mozilla Firefox (free and great), or Opera (free and awesome). They might work, and then you can isolate the problem as something wrong with Internet Explorer.



If you are on dial-up, check your service provider and see if they have certain cut-off times, or limits on connection times.



If you have cable or DSL, call your service provider and ask them (if nothing before this works) if they are dropping your connection, and if so, why.



Don't block/open any ports on your firewall, that will generally cause more problems than it fixes.



Hope this helps!

Answer 4

I just get upset. If it stays off for more than a few hours I call them to find out what is going on. I usually just go to bed for awhile. Usually, I should be in there anyway at the time. LOL.