Re: [RFC] bonding: add better ipv6 failover support

Jay Vosburgh wrote:

Brian Haley [off-list ref] wrote:

quoted

This is an RFC patch to add better IPv6 failover support for bonding
devices, especially when in active-backup mode, as reported by Alex
Sidorenko.

What this patch does:

- Creates a new Kconfig option in the IPv6 Networking section to
 compile-in the support in the bonding driver.  This also forces
 IPV6=y since that's required to link everything.

	I think it's probably better to have the IPV6 dependent bits
somehow depend on CONFIG_IPV6 rather than having a Kconfig entry.  I
doubt that many real-world users will say yes to IPv6 and bonding, but
no to the bonding IPv6 support.  I also suspect that the IPV6=y
requirement won't fly with distros.

I'm sure there's a way to do this better, for example, SCTP can be built as a module with IPv6 support and have IPV6=m.  I'll try to make it work without the option when IPV6=y or m.

quoted

- Adds a new master_ipv6 address member to the bonding struct to
 hold a copy of the primary IPv6 address on the bond.

	Do we need to issue an NS for each ipv6 address, or is one
sufficient?

It didn't seem like it from my testing, that single NS was enough to wake-up the switch when pinging either the link-local or global.  I'd have to add another global with a different prefix and re-test.

	Do ipv6 addresses configured on VLANs need one (or more) NS per
VLAN?

I didn't test with VLANs, there would probably need to be some additional work there.

	 I haven't tried the patch yet, so I'll comment further once
I've had a chance to test it (which may not be until tomorrow).

Thanks,

-Brian