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joemarkgraf's profile

New problem solver

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10 Messages

Tue, Sep 17, 2019 6:00 PM

Can not get internal IPv6 traffic to route with the CGA4131COM

Hello,

 

I am unable to get internal traffic to route to the internet with my new CGA4131COM. I have tried DHCPv6 and SLAAC and both are not working.

 

The Cisco gateway I had in the past worked find with DHCPv6 enabled. This new box isn’t working in the same manner.

Responses

Visitor

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2 Messages

1 y ago

Hello Gina,

 

We already have those settings on. I would really just like to know if there's a firmware update or hotfix to fix this modem's IPv6 issues.

 

Thanks.

Official Employee

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240 Messages

1 y ago

Hi! My name is Gabriel and I will be picking up the conversation for Gina. Thank you for taking the time out of your day to reach out to the Comcast Digital Care team for help with seeing if there is a firmware update. From what I understand, power cycling the modem will load the latest firmware made available. I would also like to try some troubleshooting steps on my end. Would you mind sending me a private message with your name, address, and account number or phone number so I can help?

New Member

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3 Messages

1 y ago

please let us know if this is resolved. i have been beating my head against this same wall since getting the "great new" router the other day after a contract renewal...i should add that this router was provided to me for my home office less than a week ago so a power cycle firmware upgrade probably not the answer.

Official Employee

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518 Messages

1 y ago

Thanks so much for taking the time to reach back out to us regarding your IPV6 issues, I am happy to look into the resolution for this for you. Since it has been some time since we last spoke can you please reach out through private message with your first and last name, full service address and account number or phone number? 

Official Employee

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518 Messages

1 y ago

Thanks so much for taking the time to reach out to us through our business forums. I would love to dig further into this with you. Can you please reach out through private message with your first and last name, full service address and account number or phone number? 

Contributor

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17 Messages

1 y ago

I just got this new modem and have the same issues as above... It refuses to pass IPv6 traffic from the delegated addresses it gave my firewall.

 

The traffic logs:

02:19:12.708251 IP6 2603:300b:XXXX:XXXX:208:a2ff:fe0c:e8e2 > 2606:4700:4700::1111: ICMP6, echo request, seq 33, length 16

02:19:12.722573 IP6 fe80::10:18ff:XXXX:c0ed > ff02::1:XXXX:e8e2: ICMP6, neighbor solicitation, who has 2603:300b:XXXX:XXXX:208:a2ff:fe0c:e8e2, length 32

The modem delgates my firewall the /59 just like the Cisco modem did prior to its replacement. The sub-interfaces are updated correctly...

 

For every PING transmitted the modem attempts to locate who owns that IP, this should not be happening. The modem delegated the subnet to my firewall/router, there is a L3 interface between the modem and the laptop. It should just forward the packet according to its routing table.

From the modem logs I see:

FW.IPv6 INPUT drop , 31 Attempts, 2020/1/21 19:35:02	Firewall Blocked 	
FW.IPv6 FORWARD drop , 129 Attempts, 2020/1/21 19:35:02	Firewall Blocked 

Odd since the firewall is disabled in the config.

The modem is approximately 6 hours old in this location. Yes I have rebooted it several times and tried it with the IPv6 firewall on/off. I have used all the 'hints' above in this forum post.

 

As people before me have said... this modem's firmware is broken. It will not route/pass IPv6 traffic from the PD ranges it assigns.

New Member

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2 Messages

2 m ago

I'm in the same boat. Comcast support has been as unhelpful as they can be. You all should hear the "customer support" recordings.... I've never encountered a company so quick to pass the buck. How are you "Top Tier" support, but you don't know how to troubleshoot IPv6 or what wireshark is? Very scary, comcast.

Unfortunately, I've looked into legal recourse against comcast in regards to this issue.

Also note that this modem blocks 6to4 (GIT) tunnel packets, so I am unable to use hurricane electric to provide my IPv6.