I've had good luck in a corporate environment using fe80::1 on Cisco 6500/7600 with newer IOS. However, some software routers still won't let you use a link-local as a VIP (at least in HSRP). I'm upgrading one of our 7200 tonight running 15.1(4)M1 to M3, hopefully that will fix it (we are upgrading it for other reasons).
For example: int vlan110 standby 110 ipv6 FE80::1 standby 110 timers msec 250 msec 750 standby 110 priority 110 standby 110 preempt delay minimum 180 ---- Matthew Huff | 1 Manhattanville Rd Director of Operations | Purchase, NY 10577 OTA Management LLC | Phone: 914-460-4039 aim: matthewbhuff | Fax: 914-460-4139 > -----Original Message----- > From: Daniel STICKNEY [mailto:dstick...@optilian.com] > Sent: Wednesday, January 25, 2012 9:42 AM > To: nanog@nanog.org > Subject: Choice of address for IPv6 default gateway > > I'm having trouble finding authoritative sources on the best common > practice (if there even is one) for the choice of address for an IPv6 > default gateway in a production server environment (not desktops). For > example in IPv4 it is common to chose the first or last address in the > subnet (.1 or .254 for example) as the VIP for VRRP/HSRP. I'm > interested in input from production environments and or > ARIN/RIPE/IANA/etc or top vendors. > > I've seen some documentation using <prefix>::1 with either a global > prefix or link-local (fe80::1). Anyone use either of these in > production and have negative or positive feedback? fe80::1 is seductive > because it is short and the idea of having the same default gateway > configured everywhere might be simple. At the same time using the same > address all around the network seems to invite confusion or problems if > two interfaces with the address ever ended up in the same broadcast > domain. > > What about using RAs to install the default route on the servers? The > 'priority' option (high/medium/low) easy fits with an architecture > using an active/standby router setup where the active router is > configured with the 'high' priority and the standby 'medium'. With the > timeout values tuned for relatively rapid (~3 seconds) failover this > might be feasible. Anyone use this in production? > > I note that VRRPv3 (and keepalived) and HSRP both support IPv6. Since > we use VRRP for IPv4, using it for IPv6 would keep our architecture the > same, which has merit too. > > Thanks in advance, > > Daniel STICKNEY >