Packet loss on Zen

[Kushan]

Just for laughs, here's what my work's current connection is looking like:

Tracing route to www.google.com [173.194.66.106]
over a maximum of 30 hops:
  0  DEVELOPMENT-04.iccsol.com [192.168.2.10] 
  1  192.168.0.1 
  2  losubs.subs.dsl3.wh-man.zen.net.uk [62.3.83.27] 
  3  ge-2-1-0-116.cr1.wh-man.zen.net.uk [62.3.80.193] 
  4  ge-3-0-0-0.cr2.th-lon.zen.net.uk [62.3.80.45] 
  5  ge-2-0-0-0.cr1.th-lon.zen.net.uk [62.3.80.41] 
  6  72.14.217.190 
  7  209.85.240.61 
  8  209.85.253.90 
  9  66.249.95.173 
 10  72.14.236.191 
 11     *        *        *     
Computing statistics for 250 seconds...
            Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address
  0                                           DEVELOPMENT-04.iccsol.com [192.168.2.10] 
                                0/ 100 =  0%   |
  1    0ms     0/ 100 =  0%     0/ 100 =  0%  192.168.0.1 
                                4/ 100 =  4%   |
  2   16ms     4/ 100 =  4%     0/ 100 =  0%  losubs.subs.dsl3.wh-man.zen.net.uk [62.3.83.27] 
                                2/ 100 =  2%   |
  3   18ms     9/ 100 =  9%     3/ 100 =  3%  ge-2-1-0-116.cr1.wh-man.zen.net.uk [62.3.80.193] 
                                0/ 100 =  0%   |
  4   24ms    10/ 100 = 10%     4/ 100 =  4%  ge-3-0-0-0.cr2.th-lon.zen.net.uk [62.3.80.45] 
                                0/ 100 =  0%   |
  5   31ms     6/ 100 =  6%     0/ 100 =  0%  ge-2-0-0-0.cr1.th-lon.zen.net.uk [62.3.80.41] 
                                0/ 100 =  0%   |
  6   31ms     7/ 100 =  7%     1/ 100 =  1%  72.14.217.190 
                                0/ 100 =  0%   |
  7   26ms     6/ 100 =  6%     0/ 100 =  0%  209.85.240.61 
                               94/ 100 = 94%   |
  8  ---     100/ 100 =100%     0/ 100 =  0%  209.85.253.90 
                                0/ 100 =  0%   |
  9  ---     100/ 100 =100%     0/ 100 =  0%  66.249.95.173 
                                0/ 100 =  0%   |
10  ---     100/ 100 =100%     0/ 100 =  0%  72.14.236.191 

Trace complete.

Weirdly enough, the actually connection is running fine and isn't causing many issues, despite it being like this since Thursday last week.

[Graham M]

TCP/IP is a pretty robust protocol

[Kushan]

Indeed. We've been on the phone to Zen and so far they've not found any issues. We'll need to do the usual plugging in different filters and checking the line for noise now.

[Chrysalis]

whilst tcp has ways to work with problems I doubt the tcp loss is anywhere near that high as you would defenitly notice it, whatever is causing the issue I suspect is mainly affecting icmp.

[Qtx]

Probably find the router or a hop along the router is dropping just the ping packets for some reason. The average latency and lack of spikes shows that there is no real problem.

[Kushan]

There's about 10% packet loss from what I can tell.

[Qtx]

Originally Posted by Kushan

There's about 10% packet loss from what I can tell.

10% icmp echo packet loss at least. Doesn't mean that any other traffic is being lost though.

The pathping suggests its happening on your gateway although if it was too much traffic for your segment, you would expect a nastier blue and yellow on the graph at the same time as the red packetloss.

[Kushan]

I don't think it's a traffic issue, the packet loss is 24hours a day, even at weekends. This is also a business connection so I'd be surprised if it was a contention issue. As you say, other traffic seems mostly fine (some sites do seem to take longer to load) but our connection speed has dropped from about 16Mbit to less than 6Mbit.

We haven't had a chance to test the line yet, I suspect it might be noise or something but we'll see.

[Kushan]

So, just as a bit of an update. For the last couple of days, our connection has gradually got worse and became noticeable. We checked our equipment and found no issues, we changed to a different modem, cable, tried the master socket and no difference.

According to Zen, the line was fine and there was no issue, it MUST be our equipment.

Then yesterday, a BT van mysteriously appeared at our cab. Our connection got more and more flaky, then dropped at about lunch time. When we came back from lunch, we rebooted the modem and hey presto:



I think there's still something going on but for now our connection is stable. I noticed a huge spool of cable outside this morning so I'm hoping they're laying fibre (Our exchange is listed as "Coming Soon" and has been for a while now).