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user_c4efd3
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Monday, April 24th, 2023 5:33 PM

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Blacklisted IP Address

​I want to preface this with I spent 5 hours on the phone with customer support and they were useless. I am also a Senior Network Engineer, so I know a lot about what I was/am asking them to do in order for me to get a new IP address. Here is my setup: I have an xfinity xfi gateway Model: CGM4981COM. I currently and have always had it in Bridge Mode with all advanced security features turned off as well as the xfinity network. The Modem itself has one Public IP Address, and my router is handed a different public IP address. The IP address that my router is handed is one a handful of public blacklists and thus preventing me from accessing websites who use those blacklists I am on to secure their network. I know residential locations do not get static IP Addresses, and I am not asking for that. But I would like an engineer at Comcast to remove my router MAC address from their switches, so that when I reboot the router, I get a new IP Address and not one that is continually blocking me from working. Oh Yeah, the most important thing is that I am not able to access my companies VDI environment because of this blacklist issue. I would like someone to reach out to me before they remove the MAC address, so that I can shutdown my router before the happens and turn it back on after completed on your end. Please Help​ @Xfinity Support @XfinityThomasB @XfinityNCOE 

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2 years ago

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flatlander3

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1.5K Messages

2 years ago

If you got it in bridge mode, what do you have it hooked to?  That's getting the DHCP/DHCPv6 address, not the gateway.  Can you spoof the MAC/DUID on whatever you got doing your routing?  Reboot the gateway after you spoof them, and you'll get a new IP.

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user_c4efd3

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13 Messages

@flatlander3​ I have a Ubiquiti UDM Pro SE, I tried Cloning the MAC, but I am not sure if I followed that exact process when I did so, I will try that now. 

2 years ago

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user_c4efd3

Visitor

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@flatlander3 So I found the MAC address of the port 4 on the XB8-T xFi Gateway that I have and put that address in my router to clone it, I lost all connectivity until I swapped it back and I waited a good 15 minutes or so. So that didn't work out. Any other thoughts?

2 years ago

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flatlander3

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1.5K Messages

@user_c4efd3​ No, you can't clone your gateway's MAC address.  This would be really bad.  Two identical MAC addresses on the same network break routing on everyone.  Same problem as a duplicate IP address.

On your Router, the first 3 digits of a MAC are the vendor prefix XX:XX:XX.  The next 3 are a unique hardware ID.  Change that to something unique.  Maybe start with FA:XXX.XXX or something.

* So.  VV:VV:VV:FA:12:34  if that wasn't clear, where VV:VV:VV is the vendor, and FA:12:34 is a unique MAC.  You just want it to be different than what you get so you get a different DHCP lease.

Reboot BOTH the gateway and router.  Perhaps other stuff too just to clear out their broken arp tables.

(edited)

2 years ago

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CCDaryl

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828 Messages

I would recommend contacting our Customer Security Assurance team about this request. They can be reached out at 888-565-4329.

I no longer work for Comcast.

2 years ago

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user_c4efd3

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@flatlander3​ - Thank you for that info, I realized that after doing it. Thank you for the added info, thought I had to clone an actual address, wasn't aware that I could just make up a MAC address. I will try this soon.

@flatlander3 & @XfinityDaryl - Curious to know, is there a reason I can not extend the fiber being brought to my house to plug directly to my router instead of using a modem that has the fiber being converted to coaxial and then back to Ethernet. I use all Ubiquiti gear and have 2 WAN ports on my router one for SFP modules and one ethernet. I would prefer to not have the modem in the way if I can help it. 

2 years ago

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EG

Expert

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107.5K Messages

2 years ago

If you are using a CGM4981COM then it is a coax connection, not fiber. You need the modem / gateway. Coax can not be connected directly to a stand-alone router.

(edited)

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user_c4efd3

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@EG​

Not sure what that is? I did check again, and it is fiber coming into the house and then converted to coaxial for some reason. Is there any chance to run that fiber directly to a Ubiquit UniFi Dream Machine SE?

2 years ago

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user_c4efd3

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@EG​ 

should have googled that before I responded the first time. Yes, I have that type of xfi gateway device and yes coaxial comes into it. But fiber comes to my house from the junction box outside, then it’s converted to coaxial, but why can’t I run the fiber directly to my router and bypass the modem?

2 years ago

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EG

Expert

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107.5K Messages

2 years ago

The optical fiber being converted to RF / coax is not typical.. Typically they use an ONT (Optical Network Terminal) to convert the fiber optic input directly into an ethernet output in their fiber installations (FTTP / FTTH). You may want to consult Comcast about the type of installation that you desire. Good luck !

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user_c4efd3

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@EG​ - This is what I am referring to, my modem is on the other end of that coax cable. 

2 years ago

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EG

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107.5K Messages

2 years ago

OK, so you have one of their somewhat rare RFoG (Radio Frequency over Glass) installations. It has its advantages over their more traditional DOCSIS / HFC type of transport. I would be very happy with it if it were available here in my market area ! It's a bit much to explain about it here but you can Google RFoG for lots of info about it.

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user_c4efd3

Visitor

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@EG​ - I should have said that earlier, I know a bit about this. My question is, can't I just plug this fiber into my 10G SFP Module on my router and bypass the modem entirely? Just getting rid of another point of failure.

2 years ago

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CCDaryl

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828 Messages

@user_c4efd3

 

If you can receive gigabit internet service to your house, then you are on our HFC network, which stands for hybrid fiber copper. Gigabit 6x, is symmetrical high speed internet service, with download and upload speeds of up to 6 Gbps. This requires Fiber to and inside the home. Here are the requirements for Gigabit 6x: https://www.xfinity.com/support/articles/requirements-to-run-xfinity-internet-speeds-over-1-gbps. Please note, that not all addresses are capable of having this service, and we would need to submit a ticket on your behalf if you are interested in the service. 

I no longer work for Comcast.

2 years ago

user_c4efd3

Visitor

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13 Messages

@XfinityDaryl​ - I’d be up for trying it out if available here. As you probably saw in my other posts, I do have 1.2Gbps service as of now. Would love symmetric service though? With what photos I posted earlier, am I not able to extend the fiber brought to my home and plug that in directly into my router and bypass the xFinity gateway? 

2 years ago

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CCDaryl

Problem Solver

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828 Messages

To get strictly fiber, you would need Gigabit 6x. I can go over the details of this with you. If you would like to look into this, please send us a direct message with your full name and address? To send a direct message, click on the "chat" icon in the upper right (which is left of the notification bell), then click on the "notepad/pencil" icon, and lastly select Xfinity Support.

I no longer work for Comcast.

2 years ago

EG

Expert

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107.5K Messages

Deleted..........................................

(edited)

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

2 years ago

EG

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107.5K Messages

2 years ago

@user_c4efd3 

AFAIK, no. They don't speak the same language.

(edited)

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EG

Expert

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107.5K Messages

2 years ago

@user_c4efd3 

Even if it is a possible stepping stone, I doubt that you would be able to get true FTTH / FTTP service if RFoG infrastructure is already in place. $$$.

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