configuring my Firewall for IPv6

I recently upgraded my cable modem and replaced the firewall in the process of troubleshooting some connectivity issues (the Netgear ProSafe FVS318Gv2 appeared to be the culprit).


Now I'm trying to dial in the configuration to maximize performance, and am having trouble getting the Firewall to stick with IPv6. Any suggestions or insights would be appreciated.


When I configure it for IPv6 with DHCPv6 it appears to work (Connection Status displays an IPv6 address), but as soon as I leave the "Broadband ISP Settings" tab in the admin. interface it appears to revert back to IPv4. The unit has the latest firmware, 4.3.5-3.


Yet when I browse to my modem (Netgear CM500, it's on the Spectrum list), it says Provisioning Mode is "IPv6 only." Firmware version is 1.01.09.


Am I doing something wrong with my configuration? Or is something going on with Spectrum?


I came across this in the FAQ:


We provide DNS resolvers in configuration information automatically provided via the Dynamic Host Configuration Protocol (DHCP and DHCPv6). At this time, we are only providing the IPv4 addresses of our DNS resolvers. We expect to add IPv6 resolvers in the coming months.


As long as IPv4 is working, your dual-stack (IPv4 and IPv6 simultaneously) configuration will still allow you to use IPv4-enabled DNS resolvers to look up IPv6 addresses.


At, I scored 7/10, and comments included:


Your IPv4 address on the public Internet appears to be
(Time Warner Cable Internet LLC)

Your IPv6 address on the public Internet appears to be 2001:0:5ef5:79fb:1868:3c61:e7a2:77ea
Your IPv6 service appears to be: Teredo
(Microsoft Corporation)

Your IPv6 connection appears to be using Teredo, a type of IPv4/IPv6 gateway. Your particular teredo configuration is only used as a protocol of last resort. When visiting a site with both IPv4 and IPv6, IPv4 will be preferred.

To ensure the best Internet performance and connectivity, ask your ISP about native IPv6. [more info]

HTTPS support is now available on this site. [more info]

Your DNS server (possibly run by your ISP) appears to have no access to the IPv6 Internet, or is not configured to use it. This may in the future restrict your ability to reach IPv6-only sites. [more info]

Re: configuring my Firewall for IPv6

Woman LOLCat LOLMan LOLRobot LOLSmiley LOL

 Don't look at that. It has nothing to do with the LAN side, it's TWC/Spectrums provisioning portal only accesable via the CMTS at the head end.




Re: configuring my Firewall for IPv6 the IPv6 settings in the Firewall have nothing to do with how my LAN connects or interacts with the WAN? I'm not a networking expert but that seems odd.

I reconfigured some of my LAN settings to IPv6 and went to again, this time it scored my readiness at 9/10. From what I can tell it means Spectrum is not yet using an IPv6 DNS server. Does that mean this is all moot until they get that accomplished?

Test with IPv4 DNS record 
ok (0.409s) using ipv4
Test with IPv6 DNS record 
ok (0.405s) using ipv6
Test with Dual Stack DNS record 
ok (0.414s) using ipv6
Test for Dual Stack DNS and large packet 
ok (0.107s) using ipv6
Test IPv4 without DNS 
skipped (0.200s)
Test IPv6 without DNS 
skipped (0.186s)
Test IPv6 large packet 
ok (1.056s) using ipv6
Test if your ISP's DNS server uses IPv6 
bad (0.317s)
Find IPv4 Service Provider 
ok (0.538s) using ipv4 ASN 11351
Find IPv6 Service Provider 
ok (0.413s) using ipv6 ASN 11351

Re: configuring my Firewall for IPv6

Looks like the IPv6 DNS is timing out which is a common issue as TWC only put in one nationwide ipv6 dns server whereas there are multiple IPv4's and located at least in every regional data center.


Ignore the provisioning interface, it has nothing to do with your lan side



Re: configuring my Firewall for IPv6

So is the bottom line I sit tight and wait for Spectrum to get with the program?


And is there anything I can do to optimize my setup for maximum performance and harden security, either with the firewall or modem? I already changed my default user and password for the firewall and the password for the modem.


Right now I seem to be running at about 50-70 Mbps download speed, 9-12 up. Spectrum seems to be advertising 100. I was told they have me on the high speed plan (I only use voice and data, no television). Is the bottleneck on their end?


Sure wish the U.S. broadband giants would go all-out on infrastructure. They sure go all-out on billing! Have read studies that indicate U.S. is at or near the top relative to other nations in average broadband cost to customers but well behind  in bandwidth and service.  We should be world leaders in this area. . .