Update 2012-03-27: It might be the physical connection from my cable modem to my provider. The cable provider says he's seeing disconnects of the modem, and they're sending a technician. (Also, please consider upvoting to help a low-rep user like me pay for his bounty...)
My setup: I have a PC with a Gigabyte GA-MA78S2H motherboard (Realtek Gigabit wired Ethernet on-board). I have the latest drivers (at least the latest driver for the NIC.
I'm connecting via an Edimax BR-6216Mg (again, wired connection), to a cable internet provider (infrastructure provider is HOT, ISP is Bezeq Intl.).
For some reason I experience short periodic disconnects and reconnects. Specifically, Skype disconnects, tries to connect, succeeds after a short while; incoming SFTP sessions get dropped; using a browser, I sometime get stuck in the DNS lookup or connection to the website and a page won't load. A couple of seconds later, a reload works.
All this happens with Windows XP SP3. With Windows 7, it also happens. (When I initially wrote this question I didn't notice it.)
ipconfig for my adapter:
Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller Physical Address. . . . . . . . . : 00-1D-7D-E9-72-9E Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 192.168.0.2 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.0.254 DHCP Server . . . . . . . . . . . : 192.168.0.254 DNS Servers . . . . . . . . . . . : 126.96.36.199 188.8.131.52 Lease Obtained. . . . . . . . . . : Saturday, March 10, 2012 8:28:20 AM Lease Expires . . . . . . . . . . : Friday, January 26, 1906 2:00:04 AM
A result of some tests a couple of the disconnects:
C:\Documents and Settings\eyalroz.BAKNUNIN>nslookup google.com DNS request timed out. timeout was 2 seconds. *** Can't find server name for address 184.108.40.206: Timed out DNS request timed out. timeout was 2 seconds. *** Can't find server name for address 220.127.116.11: Timed out *** Default servers are not available Server: UnKnown Address: 18.104.22.168 DNS request timed out. timeout was 2 seconds. DNS request timed out. timeout was 2 seconds. *** Request to UnKnown timed-out C:\Documents and Settings\eyalroz.BAKNUNIN>ping 22.214.171.124 Pinging 126.96.36.199 with 32 bytes of data: Control-C ^C C:\Documents and Settings\eyalroz.BAKNUNIN>tracert -d 188.8.131.52 Tracing route to 184.108.40.206 over a maximum of 30 hops 1 <1 ms <1 ms <1 ms 192.168.0.254 2 * * 11 ms 10.168.128.1 3 14 ms 13 ms 14 ms 220.127.116.11 4 * * * Request timed out. 5 * * * Request timed out. 6 * * 47 ms 18.104.22.168 7 31 ms 27 ms 32 ms 22.214.171.124 8 15 ms 14 ms 16 ms 126.96.36.199 9 15 ms 15 ms 11 ms 188.8.131.52 10 13 ms 29 ms 31 ms 184.108.40.206 11 35 ms 15 ms 18 ms 220.127.116.11 12 22 ms 22 ms 16 ms 18.104.22.168
I usually ping 22.214.171.124 (which is not at my ISP) with 15ms response time and no losses.
Things I've done/tried:
- [2012-03-26] I replaced the cable; I thought that made a difference, but the disconnects were back a while later, so that wasn't it.
- Updated the NIC driver.
- Tried reducing the MTU (used a utility called Dr. TCP); there was no effect.
- I updated my board BIOS revision (which caused all the HW to be "reinstalled" or re-identified - successfully).
- I installed another NIC, and tried switching to it - same effect with the on-board NIC.
- A while back I tried another router (although it was an Edimax model) - same problem.
- Connected the computer directly, with no router. Same problem.
- ping -t to the router (192.168.0.254) gives pongs, nothing is lost, and time is < 1 ms almost always (sometimes it says 1 or 2 ms). This is the case also during the disconnects.