Add IPv6 DNS Server advertisement (RDNSS) configuration and state

[dplore]

Change Scope

• Add IPv6 DNS Server advertisements (RFC8106).
• This change is backwards compatible.

Platform Implementations

Cisco:

interface ethernet 0/0
 ipv6 nd ra dns server 2001:DB8:1::1 600

Juniper:

set protocols router-advertisement interface ge-1/0/1.0 dns-server-address 2001:4860:f802::9b lifetime 1209600

Arista:

interface Ethernet1/1   mtu 9178
   ipv6 nd ra dns-server 2001:4860:4860::64 lifetime 1209600

Tree View

 module: openconfig-interfaces
   +--rw interfaces
      +--rw interface* [name]
         +--rw subinterfaces
         |  +--rw subinterface* [index]
         |     +--rw oc-ip:ipv6
         |        +--rw oc-ip:router-advertisement
         |        |  +--rw oc-ip:config
         |        |  |  +--rw oc-ip:enable?         boolean
         |        |  |  +--rw oc-ip:interval?       uint32
         |        |  |  +--rw oc-ip:lifetime?       uint32
         |        |  |  x--rw oc-ip:suppress?       boolean
         |        |  |  +--rw oc-ip:mode?           enumeration
         |        |  |  +--rw oc-ip:managed?        boolean
         |        |  |  +--rw oc-ip:other-config?   boolean
         |        |  +--ro oc-ip:state
         |        |  |  +--ro oc-ip:enable?         boolean
         |        |  |  +--ro oc-ip:interval?       uint32
         |        |  |  +--ro oc-ip:lifetime?       uint32
         |        |  |  x--ro oc-ip:suppress?       boolean
         |        |  |  +--ro oc-ip:mode?           enumeration
         |        |  |  +--ro oc-ip:managed?        boolean
         |        |  |  +--ro oc-ip:other-config?   boolean
         |        |  +--rw oc-ip:prefixes
         |        |  |  +--rw oc-ip:prefix* [prefix]
         |        |  |     +--rw oc-ip:prefix    -> ../config/prefix
         |        |  |     +--rw oc-ip:config
         |        |  |     |  +--rw oc-ip:prefix?                      oc-inet:ipv6-prefix
         |        |  |     |  +--rw oc-ip:valid-lifetime?              uint32
         |        |  |     |  +--rw oc-ip:preferred-lifetime?          uint32
         |        |  |     |  +--rw oc-ip:disable-advertisement?       boolean
         |        |  |     |  +--rw oc-ip:disable-autoconfiguration?   boolean
         |        |  |     |  +--rw oc-ip:enable-onlink?               boolean
         |        |  |     +--ro oc-ip:state
         |        |  |        +--ro oc-ip:prefix?                      oc-inet:ipv6-prefix
         |        |  |        +--ro oc-ip:valid-lifetime?              uint32
         |        |  |        +--ro oc-ip:preferred-lifetime?          uint32
         |        |  |        +--ro oc-ip:disable-advertisement?       boolean
         |        |  |        +--ro oc-ip:disable-autoconfiguration?   boolean
         |        |  |        +--ro oc-ip:enable-onlink?               boolean
+        |        |  +--rw oc-ip:dns-servers
+        |        |     +--rw oc-ip:dns-server* [ip-address]
+        |        |        +--rw oc-ip:ip-address    -> ../config/ip-address
+        |        |        +--rw oc-ip:config
+        |        |        |  +--rw oc-ip:ip-address?   oc-inet:ipv6-address
+        |        |        |  +--rw oc-ip:lifetime?     uint32
+        |        |        +--ro oc-ip:state
+        |        |           +--ro oc-ip:ip-address?   oc-inet:ipv6-address
+        |        |           +--ro oc-ip:lifetime?     uint32

[ ... snip ... ]

         +--rw oc-tun:tunnel
         |  +--rw oc-tun:ipv6
         |     +--rw oc-tun:router-advertisement
+        |     |  +--rw oc-tun:dns-servers
+        |     |     +--rw oc-tun:dns-server* [ip-address]
+        |     |        +--rw oc-tun:ip-address    -> ../config/ip-address
+        |     |        +--rw oc-tun:config
+        |     |        |  +--rw oc-tun:ip-address?   oc-inet:ipv6-address
+        |     |        |  +--rw oc-tun:lifetime?     uint32
+        |     |        +--ro oc-tun:state
+        |     |           +--ro oc-tun:ip-address?   oc-inet:ipv6-address
+        |     |           +--ro oc-tun:lifetime?     uint32

[ ... snip ... ]

         +--rw oc-vlan:routed-vlan
         |  +--rw oc-ip:ipv6
         |     +--rw oc-ip:router-advertisement
+        |     |  +--rw oc-ip:dns-servers
+        |     |     +--rw oc-ip:dns-server* [ip-address]
+        |     |        +--rw oc-ip:ip-address    -> ../config/ip-address
+        |     |        +--rw oc-ip:config
+        |     |        |  +--rw oc-ip:ip-address?   oc-inet:ipv6-address
+        |     |        |  +--rw oc-ip:lifetime?     uint32
+        |     |        +--ro oc-ip:state
+        |     |           +--ro oc-ip:ip-address?   oc-inet:ipv6-address
+        |     |           +--ro oc-ip:lifetime?     uint32