Vista & Win7 dropping connections via RVS4000

emartin · ‎07-25-2012

We have a newly-purchased RVS4000 v2 with firmware v2.0.2.7. Its intended role is as a gateway between our local network of wired workstations and a Cisco 2800 series Integrated Services Router, which is at the receiving end of our T1 line. It is configured with static IPs on both the LAN and the WAN side. It does NOT serve DHCP for the LAN. Ever since I installed it, I have had repeated complaints from users of Vista and Win7 workstations that they lose internet connectivity about every 20 - 30 minutes or so. The only solution is to unplug the workstation's CAT5 cable, count to 30, and plug it back in. Then everything's hunky dory for another 20 - 30 minutes. Meanwhile, all our Windows XP and Linux workstations enjoy uninterrupted internet access. The router/gateway we replaced (a DLink DIR-130) never had this problem.

What's going on? How can I overcome this unacceptable behavior?

Thanks in advance for any advice you can provide.

Ed Martin

Tom Watts · ‎07-25-2012

Hello Edward,

Can you describe the symptoms of the problem?

When those computers lose connection, are you able to ping the LAN interface of the RVS4000?
What is the DHCP server if the router is not it?
Are those computers going through a switch?
If you have one of the computers in question directly connected to the RVS4000 does it lose service?
Have the computers in question flush the dns, delete the arp table?
Can you do a netsh int reset all from the work station?

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/

emartin · ‎07-25-2012

1) No. But I can ping the DHCP server (see 2).

2) It's the PDC of the LAN. (IP 192.168.1.250 -- the LAN side of the RVS4000 is 192.168.1.1 and is identified as the gateway for the LAN)

3) All the workstations experiencing this problem go through switches, no two of them through the same switch.

4) I've never tried to connect one of the workstations directly. They're all 30 - 80 feet away, cabled to switches, which are in turn cabled through the ceiling to a 24-switch connected directly to the RVS4000. This setup has been working flawlessly for years with a DLink DIR-130.

5) & 6) I haven't tried that. Will do tomorrow when I'm back in the office.

Thanks for your assistance.

... Ed

emartin · ‎07-28-2012

I have now reflashed the firmware -- same version (2.0.2.7); and I've turned off IPS. The connections now are no longer dropping regularly every 20 - 30 minutes. Now it's at intervals that vary between about 40 minutes and 3 hours. I just had a colleague whose Win7 computer dropped its connection do the following in a Command Window (running as Administrator):

ipconfig /flushdns

(Connection still down)

netsh interface ip delete arpcache

(The connection came back up)

While waiting for the opportunity to run these tests with willing colleagues, I tried fiddling with the router's MTU setting. This had a noticeable effect. In particular, when I reduced it all the way to 1000, the drop-connection interval went up to more than 3 hours. But Win7 and Vista connections were still being dropped (albeit less frequently) -- and that's obviously unacceptable. However, I reset the router's MTU to 1500 before the above test was performed.

Any further suggestions? If we can't get this resolved, we're going to have to toss the router. Our 8-year-old DLink DIR-130 never gave us this kind of trouble.

... Ed

Tom Watts · ‎07-28-2012

Hi Ed,

I can't really say if I'd have more ideas for you or not. Any router (any brand) doesn't really have compatibility (or lack thereof) against operating systems. As you could tell my focus is mostly on the tcp/ip stack and trying to isolate where the point of failure may originate. I could only suggest to put the old one back and see if the problems follow it or not.

I don't know what your older router is capable of or the feature set contains, but it could be something as silly as the RSTP making a port flap for a network segment connecting to the router.

-Tom

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/

unodinove · ‎06-24-2014

I run in the same problem adding 3 client with Windows 8 (replacing 3 client with windows XP) in a lan with RVS4000 (v1.3.0.5) working in bridge mode managing a VPN and giving DHCP and firewall service.

I tryed to solve internet connection problem (for example, most of time google home page or mail server was unreachable) disabling firewall, but didn't solved all troubles: occasionally (2 o 3 times in a day) internet connection freeze for few or many minutes.

The only client left in lan with Windows XP and Server with Windows Server 2003 never had similar problems......