[c-nsp] IPv6 duplicate address

[JF Tremblay]

On Jul 1, 2014, at 2:53 PM, Mark Tinka <mark.tinka at seacom.mu> wrote:

> I remember this was happening on IOS XR in 3.9 and 4.0.x, 
> when Ethernet ports were looped for testing, and after the 
> loop is cleared, DAD keeps IPv6 from working until manual 
> intervention or a reboot.


Had the same happening each time we looped for debugging. clear ipv6 duplicate address [interface] saves the day. 

This is on of the main motivation behind http://tools.ietf.org/html/draft-ietf-6man-enhanced-dad, that suggests a nonce to be added to the nd for loop detection. The other use case is detecting when someone plugs two cable modems LAN interfaces together (nice way to blow up the LL on the CMTS!). 

/JF