IPv6 on Home Routers: FAIL

He, like other ISPs, would like to be installing IPv6-ready gear in customer homes and small businesses right now. "Every day that goes by is one more day we're assisting customers with IPv4-only routers and installing our IPv4-only DSL modems. While we know the amount of IPv6-only content on the Internet is very little today, we want to avoid rolling trucks three years from now to help people with configuring their IPv6-capable router or to replace our DSL modem. And it's not just the cost of the truck roll, but also the gear."

Bulk has tested about a dozen consumer-grade routers and DSL modems that claim IPv6 support and documented some of his test results on ARIN's IPv6 Wiki site.

"In general, it's been disappointing," he says, and he has long given up on firmware upgrades. "Most of the low-cost consumer-grade routers of the last few years have insufficient memory to support an adequate set of IPv6 features, and even those routers that do, it's not in the vendor's best interest to spend development dollars on adding features to an older product with razor-thin margins."

For instance, he says that despite earning IPv6 Forum certification for several of its WNDR products, Netgear's wares aren't ready. Last month he tested the WNDR3700v2, a unit specifically recommended by a Netgear service provider support engineer.

Bulk found bugs with how the devices implemented IPv6 support on the LAN (client) side of the router.

"In our IPv6 trial we hand out a /56 to each router. When I discovered that the PC attached to the Netgear router didn't have an IPv6 address, a little poking around revealed that the router was attempting to perform SLAAC with the full /56, rather than select a /64 out of the delegated prefix. In compliance with IETF standards, the PC wasn't getting an IPv6 address. I can only speculate, but it appears that in its testing Netgear was only handing out a /64 to each router, which likely would have resulted in a successful test. "

He alerted Netgear to the problems and reports that the company is working on fixing them.

RECENTLY: Netgear launches routers, home networking products at CES 2011

Netgear isn't alone. David Thompson, product marketing director for CPE provider ZyXEL, recently boasted about how the company implemented IPv6 support in its home networking gear way back in 2006.

Bulk responds, "David speaks positively about ZyXEL's IPv6 support, but the unfortunate reality is that their CPE is not IPv6 ready, at least not in our environment. In less than an hour of testing I showed that: PPPoEv6 was not starting/attempting to connect; the DSL modem doesn't respond to DHCPv6 solicit requests in either stateful DHCPv6 or stateless DHCPv6 mode; clients are unable to obtain an IPv6 address when the LAN interface is configured for SLAAC, etc."

Again, ZyXEL engineers are aware of these issues and are working to fix them.

Bulk names D-Link as one of the few bright spots. Several of the company's older "IPv6-ready" models operate well, but due to storage limitations still lack a stateful firewall for IPv6, an IPv4 feature that is not synonymous with, but generally bound to most implementations of consumer-grade NAT. Hardware revisions are coming this year to address those limitations and support a stateful firewall for IPv6, but Bulk said that one D-Link model has a firewall today.

"We're using the D-Link DIR-655 in our private trial, and feedback from customers has been very positive," shares Bulk. "We'd like to offer our trial customers a few other vendors to choose from, but other than Apple (which I have yet to test), I've found no other consumer-grade IPv6-ready routers in the market."

To be sure, the foot-dragging on the part of consumer equipment makers won't exactly cause an Internet Armageddon.

Homes and small business that currently have IPv4-only routers will be OK for the next couple of years, says Doyle. "For existing users, the impact should be minimal -- they already have IPv4 addresses, so there should be no problems. It's new users that will need IPv6-capable routers (or DSL modems or cable modems), and it will be up to the broadband providers to be sure they are using the right units. Eventually existing users can be retrofitted, either through firmware upgrades or through normal purchase of new routers that have IPv6 capability."

Still, it's aggravating that it's the network gear makers themselves holding things up.

Ultimately, few can disagree with Cerf's take on the matter: "It's important to get both protocols running smoothly at home. Already laptops and desktops have the capability. It's usually firewall, the NAT box and maybe the broadband modem that you have at home that haven't been configured for IPv6. So when we turn on IPv6 on a worldwide basis on June 8 as a 24-hour test (World IPv6 Day), I'm sure there will be things that don't work and those need to be addressed (no pun intended). I would much rather see a concerted effort to get everybody up and running on IPv6, and then the transition is smooth at that point because it doesn't matter if the destination is running IPv4 or 6 -- everyone can talk to everyone. That would be the desirable outcome."

Julie Bort is the editor of Network World's Cisco Subnet community site. She also writes the Microsoft Update and Source Seeker blogs. Follow Bort on Twitter @Julie188.

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