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Monday, February 17th, 2025 7:54 PM

Packet loss on be-15-arsc1.fresno.ca.ccal.comcast.net

Since a recent hardware upgrade that was performed by Comcast in our area a couple of weeks ago, I've been experiencing significant packet loss (up to 85%) from a Comcast router 5 hops away from my CPE. I've tried multiple times to get through to anyone who can help, with no resolution whatsoever. Please please help. 

Official Employee

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2.5K Messages

4 days ago

Hi there, user_0i0do3! You are at the right place for assistance with the packet loss. I apologize that you have been going through that! When you run the traceroute is that hop timing out or are you just seeing a high amount of time for the packets to go through? Were things working perfectly for you before the recent hardware upgrade? Are you noticing this all the time or at certain times of the day? 

4 Messages

Hi, the trace route is actually showing packet loss, not time outs. It happens pretty much all the time. Things were working great prior to the recent local (in my area, not my house) hardware upgrade. I'd love to post a screenshot of the trace route, but it appears that this forum software won't allow that. Please let me know if there's something I can do on my end for troubleshooting purposes. Thanks!

Official Employee

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2.5K Messages

Thank you for clarifying this further, user_0i0do3. We can help further in direct message. We are able to send packets from your account and accept pictures there. Please send us a direct message with your full name and complete service address to “Xfinity Support”. To do so, click on the direct messaging icon located at the top right of this forums page.

Here's the detailed steps to direct message us:
• Click "Sign In" if necessary
• Click the "Direct Message” icon (upper right corner of this page)
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
• Type your message in the text area near the bottom of the window
• Press Enter to send your message

I am an Official Xfinity Employee.
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Expert

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108.6K Messages

@user_0i0do3

I'd love to post a screenshot of the trace route, but it appears that this forum software won't allow that. 

FWIW. You can copy all of the text of the traceroute output and paste it into the body of your next post here instead of posting a screenshot / pic.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

4 Messages

@XfinityRay​ 

Here's the most recent trace route using 50 cycles to www.google.com from a machine on my local internal network:

Start: 2025-02-19T14:55:38-0800
HOST: XXXXX-xxx-xxxx.local        Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 192.168.1.1                0.0%    50  108.8  57.2   6.0 134.0  28.1
  2.|-- 10.61.198.67               0.0%    50   46.2  69.3  21.5 173.6  28.3
  3.|-- po-305-316-rur202.yubacit  0.0%    50   94.0  70.7  17.9 196.0  29.6
  4.|-- po-200-xar02.yubacity.ca.  0.0%    50   47.5  70.4  30.8 199.9  34.6
  5.|-- be-15-arsc1.fresno.ca.cca 74.0%    50  235.5 172.1  73.7 252.2  60.7
  6.|-- ae-501-ar01.fresno.ca.cca  0.0%    50  171.7 195.2  54.1 290.4  55.8
  7.|-- be-36421-cs02.losangeles.  0.0%    50  210.0 201.8 108.6 318.2  46.6
  8.|-- be-2211-pe11.losangeles.c  0.0%    50  213.1 194.3  72.4 327.3  49.7
  9.|-- ???                       100.0    50    0.0   0.0   0.0   0.0   0.0
 10.|-- 64.233.174.209             0.0%    50  222.4 193.7  43.3 298.0  54.6
 11.|-- 108.170.252.118            0.0%    50  229.6 194.2  43.5 276.1  52.0
 12.|-- 108.170.234.38             0.0%    50  272.4 185.1  49.2 309.0  59.5
 13.|-- 142.251.68.50              0.0%    50  209.2 194.8  39.4 287.1  57.0
 14.|-- 142.250.234.138            0.0%    50  288.5 197.5  42.8 327.6  46.7
 15.|-- 192.178.87.179             0.0%    50  225.2 193.1  39.0 298.0  49.0
 16.|-- 142.251.65.167             0.0%    50  264.0 190.6  40.2 303.7  60.5
 17.|-- sfo03s24-in-f4.1e100.net   0.0%    50  287.1 190.1  42.3 333.9  63.6

Official Employee

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1.5K Messages

@user_0i0do3, Please be careful about the information you post in public. Please send us a DM, so we can help you further. Just follow the steps above. 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Gold Problem Solver

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26.2K Messages

23 hours ago

To make the trace more readable:

HOST: XXXXX-xxx-xxxx.local        Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 192.168.1.1                0.0%    50  108.8  57.2   6.0 134.0  28.1
  2.|-- 10.61.198.67               0.0%    50   46.2  69.3  21.5 173.6  28.3
  3.|-- po-305-316-rur202.yubacit  0.0%    50   94.0  70.7  17.9 196.0  29.6
  4.|-- po-200-xar02.yubacity.ca.  0.0%    50   47.5  70.4  30.8 199.9  34.6
  5.|-- be-15-arsc1.fresno.ca.cca 74.0%    50  235.5 172.1  73.7 252.2  60.7
  6.|-- ae-501-ar01.fresno.ca.cca  0.0%    50  171.7 195.2  54.1 290.4  55.8
  7.|-- be-36421-cs02.losangeles.  0.0%    50  210.0 201.8 108.6 318.2  46.6
  8.|-- be-2211-pe11.losangeles.c  0.0%    50  213.1 194.3  72.4 327.3  49.7
  9.|-- ???                       100.0    50    0.0   0.0   0.0   0.0   0.0
 10.|-- 64.233.174.209             0.0%    50  222.4 193.7  43.3 298.0  54.6
 11.|-- 108.170.252.118            0.0%    50  229.6 194.2  43.5 276.1  52.0
 12.|-- 108.170.234.38             0.0%    50  272.4 185.1  49.2 309.0  59.5
 13.|-- 142.251.68.50              0.0%    50  209.2 194.8  39.4 287.1  57.0
 14.|-- 142.250.234.138            0.0%    50  288.5 197.5  42.8 327.6  46.7
 15.|-- 192.178.87.179             0.0%    50  225.2 193.1  39.0 298.0  49.0
 16.|-- 142.251.65.167             0.0%    50  264.0 190.6  40.2 303.7  60.5
 17.|-- sfo03s24-in-f4.1e100.net   0.0%    50  287.1 190.1  42.3 333.9  63.6

You have a problem right at the beginning, where the RTT varies from a "best" of 6ms to a "wrst" of 134ms. The packets are getting a bad start that carries on down through the rest of the trace, all the way to the target.

But all the trace packets are reaching the target, so the "loss" at hop 9 is likely more apparent than real, and probably not significant. Please see https://www.dslreports.com/faq/14068. The fact that hops beyond than ones you are concerned received the trace packets indicates that the router at that address is doing its job: forwarding data packets. The hop 9 router's failure to respond to trace packets, while annoying, is most likely not actually slowing down data transfer. If it was we'd see high RTT values and/or packet loss in all subsequent hops.

Interpreting trace results is tricky. What appears to be "late" or is reported as "lost" could mean 1) the packet did not reach or was delayed in reaching that hop, or 2) the router at that hop didn't reply or was slow to reply, or 3) the reply from that hop didn't make it back or was delayed in making it back to the trace program. And when packets vary widely right from the very start, it pretty much makes the rest of the trace meaningless. Tracking down the cause of the huge variation at hop 1 would be the place to start.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

4 Messages

Thanks for that Bruce, this is much more information than I've received from Xfinity support over the last 2 days, and I'll certainly focus on that first hop. I wasn't really concerned about hop 9, mostly hop 5, but will see if I can trace down anything on my CPE. Gracias again for your help!

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