Slow VPN on RV042

[mwsmith23]

We have PPTP configured on our Cisco RV042 VPN router. About once a day we have a severe slow down with the VPN connection. I did a tracert from home and found this on the last hop:

13   900ms  1104ms  999ms  wsip-[our ip address].dc.dc.cox.net

 All hops leading to this are fine. Just the last hop to our ip address. Would this be a problem with our RV042 or with the Cox Cable Modem?

[mdobiac]

Hello mwsmith23,

I would check your Bandwidth settings first to make sure they are at least set to 10MB over your bandwidth provide by your ISP.  So if you get 30 down and 10 up I would set the bandwidth for 40 down and 40 up to eliminate the RV042 throttling your traffic.  As the RV042 bandwidth is set in Kbps just take your bandwidth and multiply it by 1024.

After that try the following:

To isolate where the latency is at I would do some pings from the local LAN of the RV042.  

Each ping would be:

ping "LAN of RV042" -t -l 1500

ping "DG of the RV042's WAN IP addr" -t -l 1500

ping 8.8.8.8 -t -l 1500

Adjust the 1500 to 1472 or adjust by -10 until a ping goes out successfully.  So if 1472 fails attempt with 1462 and so forth.  

With this test you can see how the internal LAN is processing the traffic to the LAN of the Modem and then to the cloud.  If you are seeing excessive traffic to the Modem and to the cloud then it probably is your modem and you should consult your ISP.

Hope this helps,

Michael D.

[mwsmith23]

Thanks Michael for your response. This morning I ran the tests (at work) you suggested with these results:

ping to LAN averaged 1ms with no loss

ping to DG averaged 14ms with no loss

ping to 8.8.8.8 averaged 12ms with no loss

Now these tests were run locally this morning when the ping rate from my home was normal. The MTU I changed from Auto to 1500 on the router. Should I change it to Auto or Manual? I can look at the Cox modem signal strength screen and see normal looking readings. Again, everything was running normally this morning. I can log in to our server from home and run these tests again tonight.

Thanks again for responding to my post.

[mdobiac]

Hello mwsmith23,

Thank you for the follow up.  Yeah it looks like whatever was slowing down the network resolved itself.  Seems that either something was causing excessive processing either on the modem or router.  

If you wish to keep monitoring you can let the pings run then you can see your statistics and you might be able to see a pattern to when the traffic is slowed, or set up a syslog to see what is transpiring on the router to see what is happening.  After that it is to do a Wireshark capture to see what traffic is taking place on the network.

Regards,

Michael D.

[mwsmith23]

I noticed our internet running slow this morning. Did the tests you suggested.

ping LAN | Max=1ms Average=1ms

ping DG of WAN | Max=2181ms Avg=419ms

ping 8.8.8.8 | Max=2440ns Avg=166ms

What does this suggest?

[mdobiac]

Hello mwsmith23,

Seems the modem isn't able to handle the processing that is taking place during that test period.  You may want to consult your ISP to have them take a look at the modem or see if they need to upgrade you to a better model.  

I suggest when you contact them is when you are experiencing the degraded throughput so they can trouble shoot while it is happening.  Or get a lot of trouble shooting notes together of ping tests, packet captures if applicable, and possibly speed tests.

Regards,

Michael D.