6

Looking at the Cisco documentation for HSRP IPv6 configuration I noticed the use of 'standby 1 ipv6 autoconfig'.

interface FastEthernet0/0
 no ip address
 duplex auto
 speed auto
 ipv6 address 2020:AB8:2001::1011/64
 ipv6 enable
 standby version 2
 standby 1 ipv6 autoconfig
 standby 1 preempt delay minimum 30
 standby 1 track Serial0/0

On my setup I decided to utilize a manually configured IPv6 address for the virtual IP. Is there a reason why I should not use a static virtual address in preference of a autoconfig?

 interface GigabitEthernet0/2
  no ip address
  standby version 2
  standby 1 ipv6 2001:DB8:1:23::1/64
  standby 1 priority 110
  standby 1 preempt delay minimum 10
  duplex auto
  speed auto
  media-type rj45
  ipv6 address 2001:DB8:1:23::2/64
  ipv6 ospf 1 area 23
 end


interface GigabitEthernet0/2
  no ip address
  standby version 2
  standby 1 ipv6 2001:DB8:1:23::1/64
  duplex auto
  speed auto
  media-type rj45
  ipv6 address 2001:DB8:1:23::3/64
  ipv6 ospf 1 area 23
end
Martin Schröder
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dcrearer
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    If you are using IPv6 Prefix delegation, you may not know the prefix, and the `autoconfig` can use whatever prefix is assigned to the interface. Also, with IPv6, you can use the zero address. The network zero address is the Router Anycast address. – Ron Maupin Nov 21 '18 at 00:48
  • So is my configuration in correct? – dcrearer Nov 21 '18 at 00:49
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    I do not see anything wrong with what you have, but if you are using IPv6 Prefix Delegation, then you may want to use the `autoconfig`. – Ron Maupin Nov 21 '18 at 00:53
  • Also, remember that IPv6 uses the link-local address of a router so that multiple networks assigned to hosts all use the same address for the gateway. If you look closely at the [Cisco documentation](https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipapp_fhrp/configuration/15-sy/fhp-15-sy-book/ip6-fhrp-hsrp.html#:~:text=The%20HSRP%20is%20an%20FHRP%20designed%20to%20allow,selecting%20an%20active%20device%20and%20a%20standby%20device.), you see the standby address is a link-local address: "_standby [group-number] ipv6 {link-local-address | autoconfig}_" – Ron Maupin Aug 24 '23 at 13:06

0 Answers0