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BeardedOne's profile

New problem solver

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17 Messages

Thu, Dec 9, 2021 11:36 PM

Slow upload on static IPs

I've been trying to pin down the cause of some machines having slow internet upload speed and I seem to have tracked it down to static IPs. Machines that get NAT addresses straight from the modem have good upload speed but everything that is assigned a static IP, either routers or individual machines, ends up with slow upload speed of about 9 Mbs, NATed connections straight from the cable modem get about 35 Mbs upload.

If I reboot the modem/gateway the speed returns but only for a short while.

Anyone have a clue as to why this might be?

Accepted Solution

New problem solver

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17 Messages

10 m ago

Well, if anyone's interested in the result... The tech was out and initially said it's not possible. The speed shouldn't depend on the IP and the tech I talked to on the phone didn't know what he was talking about.  He initially connected his laptop to the modem and used DHCP for the IP and everything was fine. He said it was a configuration problem on my end. 

He seemed ready to leave at that point but I explained about the static IPs having the problem and I insisted there was an issue. He then set up a static IP on his laptop, I gave him a free one to use. I guess that's not something he does very often. After it was setup he tried a speed test again and lo and behold, slow uploads!

For lack of any other ideas he gave me a new modem. The old one is less than 6 months old but maybe I wore it out. :)

Everything seems to be working again with the new modem, static IPs and all.  

I'm not sure what was the "root problem" as they say in my business. Maybe it had something to do with the ICFR or maybe not. I'm just glad it's working properly again!

So, in the future if someone says the speed shouldn't depend on whether it's a dynamic or static IP you can you can tell them about the Bearded One and his particular issue. :)

Official Employee

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24 Messages

@BeardedOne,

Thanks so much for updating us here with your experience! 

I'm really glad to hear the fix ended up being something as easy as replacing the modem! 

 

Despite the fact that we don't hear this type of issue too often, I'll definitely keep this in mind just in case and I'm sure your update will greatly help any other customers trying to resolve similar issues too. :)

New Contributor

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19 Messages

@BeardedOne​ I have the same exact issue. Been swapping hardware all day trying to solve it just to find this thread. I get 30 mbps upstream for a short time, then it goes to 9. And I mean EXACTLY 9. Here’s the crazy thing: I have two gateways connected to the Comcast modem: there’s a switch that’s between the gateways and the modem. If I power cycle the switch the problem goes away for a random amount of time then comes back. I switch to a NAT IP (10.1.10.x) on either gateway and I maintain a solid 30Mbps.

anyway they’re coming with a new modem tomorrow at 8AM wish me luck.

(edited)

Official Employee

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32 Messages

Hello, @Joevitalee, I'm sorry to hear you had to spend so much time working on a fix but still didn't one. I'd love to take a look at your account and confirm the new modem is on its way. In order to get started can you please click the chat bubble in the top right corner and send a message to our "Comcast Business" handle? 

New Contributor

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19 Messages

@Comcast_Marcos​ I just sent a chat message.

Official Employee

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6 Messages

Thank you so much! Appreciate the direct message. We are absolutely going to make sure that this tech visit is able to remedy this issue. I can assure you that our goal is that you are always able to have the highest confidence in our products and support. I would be frustrated with the intermittent connection as well, our team works from home and knows that a consistent connection is everything. 

Official Employee

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11 Messages

10 m ago

Thank you for taking the time to reach out and being part of the Xfinity family. The upload speed isn't tied to dynamic or static Ips, you should be getting what you pay for no matter what kind of Ip you have. I'd be happy to take a look at your account to see if I can find a root cause for you. In order to get started can you please click the chat bubble in the top right corner and send a message to our "Comcast Business" handle?

New problem solver

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17 Messages

10 m ago

I don't see a chat bubble.  When I set the machine to use DHCP everything is fine but if I set a static IP the upload speed will drop considerably after a while. It happens with Windows, Linux and routers.  I'm a bit stumped myself. I've been doing this a long time and the setup hasn't changed recently. From my logs it appears to have started a few days ago.

New problem solver

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17 Messages

10 m ago

I found a chat bubble on the main screen but it says it is currently unavailable. I will call in to support tomorrow. I think I had enough of this for today. 

Official Employee

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11 Messages

No problem! Sorry we couldn't help in the way you needed today. If you need anything else after you reach out to the phone team please feel free to reach back out. 

New problem solver

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17 Messages

10 m ago

They are sending a technician out this afternoon. Apparently I have issues with ICFR errors on the transmission. They say the packets for a static IP are bigger than non static IPs due to the routing information. The bigger packets may have trouble sneaking through while the regular DHCP packets get through, usually. 


That's the theory, We shall see if it holds up. 

New Contributor

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28 Messages

9 m ago

I have this problem EXACTLY. Had tech look at it to no avail. It appeared a few weeks ago.
Rebooting the modem makes it work properly for 10 minutes. This feels like a packet shapper.
Getting VERY VERY frustrated. Below shows the cap appearing.

(edited)

New Contributor

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19 Messages

8 m ago

The tech is here and has been for 2 hours here’s what we’ve tried and not been successful yet:

New Modem.

Swapped the static 5 block for a new set of statics.

Bypassed my entire network and plugged a laptop into the modem (the tech’s laptop).

Results are the same! 35Mbps when using the 10.1.10.x IP on the router, and 9Mbps when using the static IPs.

Nobody has answers.

Official Employee

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49 Messages

I definitely understand how frustrating this is. I understand the technician is still there and has been working on finding a resolution. I'm going to set a reminder to touch base with you in an hour to see if the technician was able to resolve the issue or recommend next steps. 

New Contributor

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19 Messages

Still working at it. Could you please confirm for me that static IPs and dynamic IPs should both get the same bandwidth? We always had the full 30Mbps upload speed on our statics in the past until now.

Official Employee

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49 Messages

They should both receive the same speeds to my knowledge, however if it is a wireless connection there are varying factors that can affect the speeds. Your technician will be able to answer any of these questions as they are our expert on site. 

New Contributor

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19 Messages

Thank you. We just tried assigning a single static IP block to the modem and the problem is the same so it doesn’t have to do with a 5 block.

Official Employee

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49 Messages

Perfect! I'm going to shift my reminder out another hour to allow time for the technician to continue working. 

New Contributor

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2 Messages

7 m ago

We have been having the exact same problem for months. I called Comcast several times. Opened many tickets. Waited for tier 2 to call back, just to find out the tickets were closed immediately after hanging up with support. We are an IT shop and our clients are also having the same exact problem, even after the modems are replaced. This is a wide-spread issue. Please add me to the list of people needing an answer.

Official Employee

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10 Messages

@user_d20806 Thank you for taking the time to reach out to us on our Business forums. Please send us a direct message with your full name, business name, full address, and phone number. By clicking the "direct messaging" icon in the upper right page of our forum page. Once you click on that, input our shared handle (Comcast Business) to send us a private message.• Click "Sign In" if necessary 
• Click the "Direct Message" icon in the top right corner
• Click the "New message" (pencil and paper) icon 
• The "To:" line prompts you to "Type the name of a person". Instead, type "Comcast Business" there 
• - As you are typing a drop-down list appears. Select "Comcast Business" from that list 
• - An "Comcast Business" graphic replaces the "To:" line 
• Type your message in the text area near the bottom of the window 
• Press Enter to send it

New Contributor

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19 Messages

@user_d20806​ I have a trouble ticket that is still open, and as of Friday I last spoke with the engineer on this issue but there is no ETA. All signs point to a firmware problem. I had a tech scheduled to come give me a different model modem (the one they give to gig speed customers) because I have a theory that it will not have this problem as it is a completely different make/model. However, I was advised not to swap the modem because they wanted to have a look at my traffic in real-time.

I'm not sure if there is a way to add other customers to my ticket, but I will follow up tomorrow and let him know you have many sites with this problem. I do have some questions, though:

Are all of your customers on the same speed tier?

Are they all using the same gateway?

Approximately how many sites do you have with this problem?

The firmware team was able to look at my modem while I was passing traffic and see what the problem is, but did not have a solution.

(edited)

New Contributor

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2 Messages

They are not all the same tier but all the uploads should be 25-35 and they are all getting 1-2.

The sites I've been to and tested myself are all on the same style modem. I have not compared part numbers.

We have six sites that are actively complaining about it.

New Contributor

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28 Messages

We can verify 4 separate sites that seem to be locked at 10Mbit upstream. All on the same 300/35 rate.
Everything worked at each site before and all started showing problems between 11/15/2020 and 1/1/2022.

Official Employee

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19 Messages

I understand you were having issues. Are you currently still having internet speed concerns? 

New Contributor

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2 Messages

5 d ago

I am currently suffering the worst Upstream issues I have ever encountered.

Upload speeds that go from 20Mbps to 0.08Mbps when under load on a Business Class service at a premium for over 10months, 5 modems, 10 technicians, 2 field service calls and help from Tier2 repair support since March

Texas Comcast management refuses to take ownership of the Problem.

The Problem is identified outside of the Office ... outside of closest pedestal, outside of closest node, and I can get no movement on getting a resolution to this service problem.

The service problem even presents itself when you remove the Office from the modem with all wifi off.

What needs to be done to get help with Quality of service issues when the Comcast Customer Service says we can help no further because upper management will not recognize this as a problem.

What needs to be done when the Comcast customer service rep suggest you contact the Better Business Bureau and the local Attorney General's office to get help with your problem.

"Core Values"

Comcast core values comprise “integrity, entrepreneurial spirit, respect, and giving back.” The culture of this company proves that it is a people-centered rather than a self-centered one. This is shown by the manner in which the company respects its customers and all stakeholders while delivering its services."

Where is the integrity in honoring the promise of reliable business class service and listening to your employees when they tell you the issue at a clients office is outside the office.

Comcast Where is your integrity to fix this?

12yr of loyalty to Business class service should count for something!