[154904] in North American Network Operators' Group
Re: using "reserved" IPv6 space
daemon@ATHENA.MIT.EDU (Rajendra Chayapathi (rchayapa))
Mon Jul 16 18:03:25 2012
From: "Rajendra Chayapathi (rchayapa)" <rchayapa@cisco.com>
To: Oliver <olipro@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>, "nanog@nanog.org"
<nanog@nanog.org>
Date: Mon, 16 Jul 2012 22:02:50 +0000
In-Reply-To: <2059648.BTFFAkdkz4@lsdsrv>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
True .. Your point of the ICMPv6 storm is on mark and is one of the
drawbacks for this solution.
On 7/16/12 12:39 PM, "Oliver" <olipro@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
wrote:
>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..
>>=20
>> 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.
>>=20
>
>In all honesty, I think using ND as the failover method is a generally
>bad=20
>idea - you have no way of ensuring all endpoints take note of or honour
>the=20
>router preference flag.
>
>Additionally, having a 1 second validity lifetime is going to create a
>lot of=20
>ICMPv6 spam across the segment - big deal? perhaps not. But when
>contrasted=20
>with the fact that it can be wholly avoided using one of the
>aforementioned=20
>redundancy protocols, why would you do it?
>
>Additionally, as an alternative to RAs, you can simply point default at
>the=20
>all-routers anycast address.
>
>Regards,
>Oliver
>
