using "reserved" IPv6 space

Oliver olipro at
Mon Jul 16 19:39:46 UTC 2012

On Monday 16 July 2012 18:26:08 Rajendra Chayapathi wrote:
> On the HSRP/ND part , this all falls in the First Hop redundancy areana
> and can be achieved via any of the following and each has its merits and
> cons..
> 1) Using ND -- need to tune the "IPv6 nd reachable time" to achieve the
> faster failover
> 2) Using any of the First hop redundancy protocol ( HSRP, VRRP , GLBP)
> 3) Default route selection.

In all honesty, I think using ND as the failover method is a generally bad 
idea - you have no way of ensuring all endpoints take note of or honour the 
router preference flag.

Additionally, having a 1 second validity lifetime is going to create a lot of 
ICMPv6 spam across the segment - big deal? perhaps not. But when contrasted 
with the fact that it can be wholly avoided using one of the aforementioned 
redundancy protocols, why would you do it?

Additionally, as an alternative to RAs, you can simply point default at the 
all-routers anycast address.


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