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.
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.
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