FS#37292 - [netctl] doesn't support Optimistic Duplicate Address Discovery

Attached to Project: Arch Linux
Opened by Pierre-Julien Bringer (Pharisian) - Friday, 11 October 2013, 13:42 GMT
Last edited by Jouke Witteveen (jouke) - Tuesday, 04 March 2014, 09:50 GMT
Task Type Feature Request
Category Arch Projects
Status Closed
Assigned To Jouke Witteveen (jouke)
Architecture All
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Votes 0
Private No

Details

If a profile is configured for stateless IPv6, netctl waits until the tentative address can be verified unique. However, if the kernel is configured for Optimistic Duplicate Address Detection (RFC 4429), this delay shouldn't be introduced.

In many situations, the risk of collision of IPv6 addresses is negligible. Optimistic DAD allows faster network start times in those cases. It is not enabled by default.

Steps to reproduce:
1. Configure kernel for Optimistic DAD: sysctl -w net.ipv6.conf.all.optimistic_dad=1
2. Start profile with stateless IPv6
3. The delay is observable, and can be understood using tools like tcpdump
   odad.diff (0.8 KiB)
This task depends upon

Closed by  Jouke Witteveen (jouke)
Tuesday, 04 March 2014, 09:50 GMT
Reason for closing:  Upstream
Comment by Jouke Witteveen (jouke) - Monday, 21 October 2013, 12:47 GMT
Isn't this a bug in `ip`? This bug suggests that `ip -6 addr show dev "$Interface" tentative` also lists addresses of type/state 'optimistic', which are not tentative in the sense of the RFC.

Loading...