Change Details

## Reproduce Issue Start DHCPv6 client on an interface ``` set interfaces ethernet eth1 vif 1337 dhcpv6-options pd 1 interface eth2 sla-id 0 set interfaces ethernet eth1 vif 1337 dhcpv6-options pd 1 interface eth2 address 1 set interfaces ethernet eth1 vif 1337 address dhcpv6 commit ``` Delete SVI ``` delete interfaces ethernet eth1 vif 1337 time commit ``` ``` real 0m1.363s user 0m0.598s sys 0m0.266s ``` Delete entire base interface including SVI ``` delete interfaces ethernet eth1 time commit ``` ``` real 0m30.867s user 0m0.602s sys 0m0.232s ```

## Reproduce Issue Start DHCPv6 client on an interface ``` set interfaces ethernet eth1 vif 1337 dhcpv6-options pd 1 interface eth2 sla-id 0 set interfaces ethernet eth1 vif 1337 dhcpv6-options pd 1 interface eth2 address 1 set interfaces ethernet eth1 vif 1337 address dhcpv6 commit ``` Delete SVI ``` delete interfaces ethernet eth1 vif 1337 time commit ``` ``` real 0m1.363s user 0m0.598s sys 0m0.266s ``` Delete entire base interface including SVI ``` delete interfaces ethernet eth1 time commit ``` ``` real 0m30.867s user 0m0.602s sys 0m0.232s ``` With the fix the DHCPv6 server also does see a proper release message: ``` Sep 13 10:47:11 dhcpd[6000]: Release message from fe80::250:56ff:feb3:38c5 port 546, transaction ID 0xE0EC0F00 Sep 13 10:47:11 dhcpd[6000]: Client 00:04:42:3f:67:73:77:df:c4:80:42:c9:42:af:ff:15:de:0b releases prefix fc00:0:3:ff00::/60 Sep 13 10:47:11 dhcpd[6000]: Sending Reply to fe80::250:56ff:feb3:38c5 port 546 ```

## Reproduce Issue Start DHCPv6 client on an interface ``` set interfaces ethernet eth1 vif 1337 dhcpv6-options pd 1 interface eth2 sla-id 0 set interfaces ethernet eth1 vif 1337 dhcpv6-options pd 1 interface eth2 address 1 set interfaces ethernet eth1 vif 1337 address dhcpv6 commit ``` Delete SVI ``` delete interfaces ethernet eth1 vif 1337 time commit ``` ``` real 0m1.363s user 0m0.598s sys 0m0.266s ``` Delete entire base interface including SVI ``` delete interfaces ethernet eth1 time commit ``` ``` real 0m30.867s user 0m0.602s sys 0m0.232s ``` With the fix the DHCPv6 server also does see a proper release message: ``` Sep 13 10:47:11 dhcpd[6000]: Release message from fe80::250:56ff:feb3:38c5 port 546, transaction ID 0xE0EC0F00 Sep 13 10:47:11 dhcpd[6000]: Client 00:04:42:3f:67:73:77:df:c4:80:42:c9:42:af:ff:15:de:0b releases prefix fc00:0:3:ff00::/60 Sep 13 10:47:11 dhcpd[6000]: Sending Reply to fe80::250:56ff:feb3:38c5 port 546 ```