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Monday, March 16th, 2020 8:00 AM

IPv6 routing from a PD subnetwork

Hello,

I browsed some topics here and all of them ends with a suggestion of a private contact instead of a solution. I have a problem similar to some of discussed.

I have a firewall (SonicWALL TZ300) connected to DPC3941B Comcast gateway. Some computers connected to the gateway as well, but most of them connected to the internal firewall's interface.

IPv6 works fine for all nodes connected directly to the gateway (...:2400::/64), but it does not work for those connected to the firewall (prefix-delegated ...:24e0::/64)

Two weeks ago everything worked fine, but then something was changed in the comcast setup and after that IPv6 stopped working from the delegated subnetwork.

 

On the gateway I can see in the Firewall Logs the following record:

FW.IPv6 FORWARD drop , 15875 Attempts, 2020/3/16 09:39:42Firewall Blocked

Does that indicate the gateway refuses forwarding packets from/to the delegated subnetwork?

Also, I did the following test: on a PC connected to the gateway, I added a static route pointing to the firewall's external link-local address. After that I was able to access that PC from a PC on the internal network (behind the firewall). That indicates that the firewall is capable to route the IPv6 traffic.

On the firewall the routing looks like the following:

Idx        Act ref Source Destination                                  Gateway                   Interface     Metric Distance Priority
-----------------------------------------------------------------------------------------------------------------------------------------
2          Yes 0   Any    ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff/128  ::                        X0 (LAN)      20     20       1
11         Yes 0   Any    xxxx:xxxx:xxxx:2400::/64                     ::                        X1 (WAN)      20     20       5
15         Yes 2   Any    xxxx:xxxx:xxxx:24e0::/64                     ::                        X0 (LAN)      20     20       6
14         Yes 0   Any    X1 Delegated Prefix                          ::                        Drop_TunnelIf 255    Auto     7
10         Yes 0   Any    ::/0                                         fe80::82b2:34ff:fe34:3b95 X1 (WAN)      50     50       11
1          Yes 0   Any    ::/0                                         ::                        X1 (WAN)      255    255      12

Route Advertisement is disabled (enabling it did not help).

 

Because of the coronavirus quarantine I we could use the IPv6 for direct access to work computers from home, since the VPN server capabilities are limited, but IPv6 has stopped working right before it needed most.

Please advise.

 

 

Problem solver

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348 Messages

4 years ago

Hi there, thanks so much for taking the time to reach out to the Digital Care Team here through the forums. I am sorry that you are also having an issue with your routing and you have reached the right team to help make sure we get this taken care of. Sometimes we do have to take a look at your account and equipment to help reach a resolution. Can you please send us a private message with your name, the full address, and phone/account number? 

Contributor

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13 Messages

4 years ago

I can confirm that IPv6 is not routing on a DPC3941B with statics. I am able to receieve a prefix delegation on my router but no comunications.

 

I suspect that Comcast broke it when they upgraded the firmware. Now I have the same issue that I had with the CGA4131COM. Comcast had swaped it out to DPC3941B just so I could get ipv6 and now I have to deal with the DPC3941B puma chip latency issue.

 

Bottom line Comcast can't seem to get this issue fixed on their end... these devices have firmware issues. I wasted a month going back an forth with the CGA4131COM, comcast had no idea how to fix it.

Official Employee

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526 Messages

4 years ago

Thanks for taking the time to reach out to us through our business forums and I am very sorry for the delay in our response. I know how important the internet service is to your business and I would love to assist with the IPV6 routing issues. 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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19 Messages

4 years ago

I wish you luck... I faced the same problem for months. At this point I have given up and NAT'ed some things out a single IPv6.

Problem solver

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348 Messages

4 years ago

Hi there, we are so sorry for the delayed response and you have reached the right team to help with your IPv6 concerns. I know how frustrating this can be and you have reached the right team to help make sure we get this taken care of. Can you please send us a private message with your name, the full address, and the account number?