Choice of address for IPv6 default gateway

Daniel STICKNEY dstickney at optilian.com
Wed Jan 25 08:41:36 CST 2012


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




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