Orbi WiFi 7 RBE973
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Diagnosing 2% Packet Loss

SamirD
Prodigy

Diagnosing 2% Packet Loss

We use a rebooter to monitor the health of our fvs114 and reboot it when necessary. The rebooter also monitors the Internet connection by pinging to several popular and stable sites.

In the last few days, the connection has had consistent very minor packet loss. Speed tests also show that the full speeds we are paying for are not possible to reach.
www.google.com 173.194.46.116 30 ms 3 %
www.yahoo.com 98.139.180.149 50 ms 2 %
www.bing.com 204.79.197.200 10 ms 1 %
www.ask.com 23.3.96.88 60 ms 3 %

At first I thought this was the ISP's problem, as a similar thing happened a few weeks ago when they were adding more digital cable infrastructure to our market.

But after the tech came out and plugged into the modem directly, there was no loss or speed problems, pointing to something inside our network.

The cable modem plugs directly into the fvs114 and then the fvs114 is then distributed to the rest of the network via a few direct connections to the switch on the 114 and connection to two switches. There are some cable runs to and from the 114 as it is in another part of the of the office (for ease of physical management), but they have been fine for better part of a decade.

Where would you start the diagnosis after I confirm the tech's results by plugging directly into the cable modem?
Message 1 of 10

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fordem
Mentor

Re: Diagnosing 2% Packet Loss

2%, 3% loss over what time period? Personally, I'm against the use of a ping as a tool to diagnose anything other than a connectivity issue, I've seen far too many people, professionals included, in a futile search fro problems that they perceive exist because of the way they use the tool. Worrying about 2~3% packet loss across the internet, where you have no control, of the route the traffic takes, and no idea of what's going on along that route is nothing more an exercise in futility. Ping the inside interface of your router - if you have packet loss - that is inside your network, you can find the cause & fix it, ping the external interface of your router (be very careful here if you have a dynamic address, as it may change), if you have packet loss to the external interface that is not present to the internal interface, you may want to take a closer look at what the router is doing. One caution - note I said packet loss - you can expect to see variations in the response times, as far as the router is concerned, responding to ping requests is not a matter of urgency, and does not receive a high priority, it will reply when it can, and if you get a time out (which will be shown as packet loss) because of that, as far as the router is concerned - tough luck, try again later.

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Message 2 of 10

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fordem
Mentor

Re: Diagnosing 2% Packet Loss

2%, 3% loss over what time period? Personally, I'm against the use of a ping as a tool to diagnose anything other than a connectivity issue, I've seen far too many people, professionals included, in a futile search fro problems that they perceive exist because of the way they use the tool. Worrying about 2~3% packet loss across the internet, where you have no control, of the route the traffic takes, and no idea of what's going on along that route is nothing more an exercise in futility. Ping the inside interface of your router - if you have packet loss - that is inside your network, you can find the cause & fix it, ping the external interface of your router (be very careful here if you have a dynamic address, as it may change), if you have packet loss to the external interface that is not present to the internal interface, you may want to take a closer look at what the router is doing. One caution - note I said packet loss - you can expect to see variations in the response times, as far as the router is concerned, responding to ping requests is not a matter of urgency, and does not receive a high priority, it will reply when it can, and if you get a time out (which will be shown as packet loss) because of that, as far as the router is concerned - tough luck, try again later.
Message 2 of 10
adit
Mentor

Re: Diagnosing 2% Packet Loss

Old router. How fast is your connection?
Message 3 of 10
SamirD
Prodigy

Re: Diagnosing 2% Packet Loss

fordem wrote:
2%, 3% loss over what time period?

Personally, I'm against the use of a ping as a tool to diagnose anything other than a connectivity issue, I've seen far too many people, professionals included, in a futile search fro problems that they perceive exist because of the way they use the tool.

Worrying about 2~3% packet loss across the internet, where you have no control, of the route the traffic takes, and no idea of what's going on along that route is nothing more an exercise in futility.

Ping the inside interface of your router - if you have packet loss - that is inside your network, you can find the cause & fix it, ping the external interface of your router (be very careful here if you have a dynamic address, as it may change), if you have packet loss to the external interface that is not present to the internal interface, you may want to take a closer look at what the router is doing.

One caution - note I said packet loss - you can expect to see variations in the response times, as far as the router is concerned, responding to ping requests is not a matter of urgency, and does not receive a high priority, it will reply when it can, and if you get a time out (which will be shown as packet loss) because of that, as far as the router is concerned - tough luck, try again later.


adit wrote:
Old router. How fast is your connection?
The rebooter pings once every 10 seconds to the sites/IPs I posted. It also pings our router internal lan address and reboots if it timeouts for more than 5 seconds. The fvs114 almost instantly reboots, so this works quite well.

I actually wouldn't worry about the packet loss except that it used to be zero across the board. I've also seen problems with rdp sessions dropping as well as other data transfers including a speed test. The packet loss is indicating an actual problem somewhere.

I tried the ping to internal/external IPs and everything is rock solid with zero loss. Pings to anything external seem to have issues--our other sites via site-to-site (normally zero loss), our ISPs web site (normally zero loss), and of course what the rebooter has been pinging.

Our ISP came out again to examine the tap where the cable comes from. I think they may have something going on even though it may not have shown up in the tests the tech did. I'll be there this Sunday, so hopefully I can figure it out. What's interesting is that the loss percentage has dropped quite a bit and performance is approaching normal for all communications (rdp, file xfers, speedtests, etc.):
www.google.com	74.125.225.18	40 ms	3 %
www.yahoo.com 98.138.253.109 60 ms 1 %
www.bing.com 204.79.197.200 10 ms 0 %
www.ask.com 184.26.143.137 20 ms 1 %


Yes, old router, but sat around unused for better part of a decade. Connection is 25/5 cable modem. Full speeds without any problems for the last few years in same usage patterns.
Message 4 of 10
fordem
Mentor

Re: Diagnosing 2% Packet Loss

SamirD wrote:
I tried the ping to internal/external IPs and everything is rock solid with zero loss.


This suggests that the problem is not router related, but lies "upstream" of the router - do a traceroute to an internet host and see what the hop directly after the router is, ping that and see if you're getting loss to it, if you're not, proceed through the traceroute results hop-by-hop and you'll find where the problem lies.

If you are getting loss to that first hop, try swapping the router out and see what happens - it is theoretically possible that the WAN port could be defective, but I think that would more likely be a hard failure.

There is a fair bit of hardware between the routers WAN port and the next hop - cable modem, two way cable amplifiers, of course the cable itself, and all the equipment at the cable head end - noise, interference, bad connections are all possibilities.
Message 5 of 10
SamirD
Prodigy

Re: Diagnosing 2% Packet Loss

I tried that and got the same level of loss there. At this point i assumed either the techs assessment was correct, pointing to our hardware, or that he didnt fully test the line for loss. A tech returning to check our lines the other day and the pings improving, which wouldnt necessaily happen with an equipment failure, make me suspect a line quality issue and nothing wrong with our network.
Message 6 of 10
SamirD
Prodigy

Re: Diagnosing 2% Packet Loss

Problem fixed! And I didn't touch a thing. 🙂 Definitely an ISP issue. :rolleyes:
www.google.com	74.125.225.19	40 ms	0 %
www.yahoo.com 98.139.180.149 40 ms 0 %
www.bing.com 204.79.197.200 20 ms 0 %
www.ask.com 64.210.100.96 20 ms 0 %
Message 7 of 10
SamirD
Prodigy

Re: Diagnosing 2% Packet Loss

And the problem returns: 😞
www.google.com	173.194.46.81	30 ms	2 %
www.yahoo.com 98.139.183.24 Timeout 2 %
www.bing.com 204.79.197.200 10 ms 2 %
www.ask.com 23.63.227.210 20 ms 2 %


What was interesting is that when the loss went to zero, the upload speeds from the other side of a site-to-site vpn varied from normal (2mb+) to less than 500k. This wasn't a problem before.

And now, this bandwidth limit has also become an issue. It's only 336k right now--barely as fast as three bonded isdn lines. :mad:
Message 8 of 10
SamirD
Prodigy

Re: Diagnosing 2% Packet Loss

And it went away again until today. :mad: I'm on hold with their support right now. Let's see what they [don't] do this time. :rolleyes:
Message 9 of 10
SamirD
Prodigy

Re: Diagnosing 2% Packet Loss

Target Site	IP Address	Response Time	Timeout
www.google.com 74.125.225.16 30 ms 2 %
www.yahoo.com 98.139.183.24 40 ms 1 %
www.bing.com 204.79.197.200 20 ms 2 %
www.ask.com 23.63.227.179 20 ms 1 %
Message 10 of 10
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