IPv6 Neighbor Discovery
Neighbor discovery is a protocol used for IPv6 traffic that allows different nodes on the same link to advertise their existence to their neighbors, and to learn about the existence of their neighbors.
IPv6 Neighbor Discovery Overview
Neighbor discovery is a protocol that allows different nodes on the same link to advertise their existence to their neighbors and learn about their neighbors.
Routers and hosts (nodes) use Neighbor Discovery (ND) messages to determine the link-layer addresses of neighbors on attached links and to overwrite invalid cache entries. Hosts also use ND to find neighboring routers that can forward packets on their behalf.
Nodes rely on ND to actively track whether neighbors are reachable. When a router (or the path to a router) fails, nodes actively search for alternative paths to reach the destination.
This section discusses the following topics:
Improvements over IPv4 Protocols
IPv6 Neighbor Discovery corresponds to several IPv4 protocols such as Address Resolution Protocol (ARP), Internet Control Message Protocol (ICMP) Router Discovery, and ICMP Redirect.
Neighbor Discovery provides many improvements over that IPv4 set of protocols. These improvements address the following:
-
Router discovery—Enables a host to find routers on an attached link.
-
Prefix discovery—Allows a host to discover address prefixes for destinations on an attached link and differentiate between onlink destinations and those reachable only through routers.
-
Parameter discovery—Supplies a node with link and Internet parameters for outgoing packets.
-
Address resolution—Lets a node find a link-layer address for onlink destinations by using only an IPv6 address.
-
Next-hop determination—Provides an algorithm for mapping an IPv6 destination address to a neighbor's address, identifying the next router or destination.
-
Neighbor unreachability detection—Helps a node confirm that a neighbor remains reachable.
-
Duplicate address detection (DAD)—Alerts a node to any address conflicts before it finalizes an address assignment.
A router periodically multicasts a router advertisement from each of its multicast interfaces to announce its availability. Hosts listen to the router advertisements to configure addresses automatically and identify the link-local addresses of nearby routers. When a host starts, it multicasts a router solicitation to ask for immediate advertisements.
Router discovery messages are not a routing protocol. These messages allow hosts to find neighboring routers, but hosts do not use router discovery messages to decide which router is ideal for reaching a specific destination.
Neighbor discovery works through ICMP version 6 (ICMPv6) messages: router solicitation, router advertisement, neighbor solicitation, neighbor advertisement, and redirect.
For IPv6, neighbor discovery replaces the IPv4 protocols router discovery (RDISC), ARP, and ICMPv4 redirect.
Junos OS Release 9.3 and later supports Secure Neighbor Discovery (SEND).
SEND lets operators protect NDP messages. This security method applies to links where physical security is questionable, and NDP message attacks are a concern.
The Junos OS safeguards NDP messages by using cryptographically generated addresses (CGAs).
Router Discovery
A router advertisement can contain a set of prefixes. Nodes rely on these prefixes for address autoconfiguration, to maintain a database of onlink (same data link) prefixes, and to conduct DAD. If a node is onlink, the router forwards packets to that node. If the node is not onlink, the routing process forwards the packets to the next router for consideration. Each prefix entry can include a prefix length, a valid lifetime, a preferred lifetime, an onlink flag, and an autoconfiguration flag. These parameters enable address autoconfiguration and govern link settings such as the maximum transmission unit (MTU) size and hop limit.
Junos OS Release 22.4R1 and later supports NAT64 IPv6 address prefix router advertisement. The router includes the configured NAT64 IPv6 address prefix in router advertisement packets. You can configure as many as three NAT64 IPv6 address prefixes per interface.
Configure
the NAT64 IPv6 address prefix with
set protocols router-advertisement interface
<interface-name> nat-prefix
<prefix>.
Set
the advertisement time with
set protocols router-advertisement interface
<interface-name> nat-prefix
<prefix> lifetime
<lifetime>.
Address Resolution
ICMPv6 neighbor discovery replaces ARP in IPv6 for mapping network addresses to link-layer addresses. Neighbor discovery also handles changes in link-layer addresses, inbound load balancing, anycast addresses, and proxy advertisements.
Nodes that want a target node’s link-layer address multicast a neighbor solicitation message carrying the target’s address.
Nodes use neighbor solicitation and advertisement messages to verify duplicate unicast addresses on the same link.The autoconfiguration of an IP address depends on the presence of a duplicate address on the same link. DAD is a requirement for autoconfiguration.
Nodes also employ neighbor solicitation and advertisement messages to perform neighbor unreachability detection. Neighbor unreachability detection checks a target node’s presence on a link.
Redirect
Routers use redirect messages to notify a host about a more suitable next-hop router or an onlink neighbor for a given destination. This mechanism is similar to ICMPv4 redirect.
Routers employ the ICMPv6 redirect message to inform on-link hosts of a better next-hop for specific destinations.
This functionality allows routers to help hosts choose more efficient local routing paths.
SLAAC
Beyond other improvements to IPv6, Neighbor Discovery also supports Stateless Address Autoconfiguration (SLAAC). IPv6 maintains the capability for stateful address assignment through DHCPv6 (and static assignment), but
SLAAC provides a streamlined approach to address configuration that suits many network environments.
SLAAC offers plug-and-play (PnP) IP connectivity in two phases:
Phase 1: Link-local address assignment
Phase 2: Global address assignment
-
Phase 1—Link-local address assignment:
Link-Local Address Generation: Whenever an IPv6-enabled interface, capable of multicasting, activates, the node generates a link-local address by combining its interface identifier with the FE80::/10 prefix.
The system does not allow users to remove the auto-generated link-local address, but an administrator can override it with a manually configured one.
Duplicate Detection: Before assigning the new link-local address to its interface, the
Node tests uniqueness with a Neighbor Solicitation message sent to that address.
If a reply arrives, the node identifies the address as a duplicate and halts the process, which requires manual intervention.Link-Local Address Assignment:
If the address remains unique, the node assigns it to the interface.
At this point, the node has IPv6 connectivity to all other nodes on the same link. Only hosts proceed to Phase 2, while routers configure their interface addresses through alternate methods.
Phase 2—Steps for global connectivity:
Router Advertisement:
The host sends a Router Solicitation that prompts onlink routers to issue their router advertisements. When an administrator enables stateless autoconfiguration on the router, each router advertisement provides a subnet prefix that neighboring hosts can use.Global Address Generation:
After the host obtains a subnet prefix, it combines that prefix with its interface identifier to create a global address.DAD: The host again runs DAD, but this time for the newly generated global address.
Global Address Assignment:
If no duplication is detected, the host assigns that global address to its interface.
Supported ICMP Router Discovery and IPv6 Neighbor Discovery Standards
Junos OS substantially supports the following RFCs, which define standards for the Internet Control Message Protocol (ICMP for IP version 4 [IPv4]) and neighbor discovery (for IP version 6 [IPv6]).
RFC 1256, ICMP Router Discovery Messages
RFC 4861, Neighbor Discovery for IP version 6 (IPv6)
RFC 2463, Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification
RFC 4443, Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification
RFC 4862, IPv6 Stateless Address Autoconfiguration
RFC 8335, PROBE: A Utility for Probing Interfaces
Example: Configuring IPv6 Interfaces and Enabling Neighbor Discovery
This example shows how to configure the router or switch to send IPv6 neighbor discovery messages.
Requirements
In this example, no special configuration beyond device initialization is required.
Overview
In this example, all of the interfaces in the sample topology are configured with IPv6 addresses. If you plan to extend IPv6 functionality into your LAN, datacenter, or customer networks, you might want to use Stateless Address Auto-Configuration (SLAAC) and that means configuring router advertisements. SLAAC is an IPv6 protocol that provides some similar functionality to DHCP in IPv4. Using SLAAC, network hosts can autoconfigure a globally unique IPv6 address based on the prefix provided by a nearby router in a router advertisement. This removes the need to explicitly configure every interface in a given section of the network. Router advertisement messages are disabled by default, and you must enable them to take advantage of SLAAC.
To configure the router to send router advertisement messages, you must include at least the following statements in the configuration. All other router advertisement configuration statements are optional.
protocols {
router-advertisement {
interface interface-name {
prefix prefix;
}
}
}
To configure neighbor discovery, include the following statements. You configure router advertisement on a per-interface basis.
protocols {
router-advertisement {
interface interface-name {
current-hop-limit number;
default-lifetime seconds;
(link-mtu | no-link-mtu);
(managed-configuration | no-managed-configuration);
max-advertisement-interval seconds;
min-advertisement-interval seconds;
(other-stateful-configuration | no-other-stateful-configuration);
prefix prefix {
(autonomous | no-autonomous);
(on-link | no-on-link);
preferred-lifetime seconds;
valid-lifetime seconds;
}
reachable-time milliseconds;
retransmit-timer milliseconds;
solicit-router-advertisement-unicast;
virtual-router-only;
}
traceoptions {
file filename <files number> <size maximum-file-size> <world-readable | no-world-readable>;
flag flag;
}
}
}
Topology
Figure 1 shows a simplified sample topology.
This example shows how to make sure that all of the IPv6 hosts attached to the subnets in the sample topology can auto-configure a local EUI-64 address.
CLI Quick Configuration shows the configuration for all of the devices in Figure 1. #d15e202__d15e370 describes the steps on Device R1.
Configuration
Procedure
CLI Quick Configuration
To quickly configure this
example, copy the following commands, paste them into a text file,
remove any line breaks, change any details necessary to match your
network configuration, and then copy and paste the commands into the
CLI at the [edit] hierarchy level.
Device R1
set interfaces fe-1/2/0 unit 1 description to-P2 set interfaces fe-1/2/0 unit 1 family inet6 address 2001:db8:0:1::/64 eui-64 set interfaces fe-1/2/1 unit 5 description to-P4 set interfaces fe-1/2/1 unit 5 family inet6 address 2001:db8:0:5::/64 eui-64 set interfaces fe-1/2/2 unit 9 description to-P3 set interfaces fe-1/2/2 unit 9 family inet6 address 2001:db8:0:9::/64 eui-64 set interfaces lo0 unit 1 family inet6 address 2001:db8::1/128 set protocols router-advertisement interface fe-1/2/0.1 prefix 2001:db8:0:1::/64 set protocols router-advertisement interface fe-1/2/1.5 prefix 2001:db8:0:5::/64 set protocols router-advertisement interface fe-1/2/2.9 prefix 2001:db8:0:9::/64
Device R2
set interfaces fe-1/2/0 unit 2 description to-P1 set interfaces fe-1/2/0 unit 2 family inet6 address 2001:db8:0:1::/64 eui-64 set interfaces fe-1/2/1 unit 14 description to-P3 set interfaces fe-1/2/1 unit 14 family inet6 address 2001:db8:0:14::/64 eui-64 set interfaces fe-1/2/2 unit 21 description to-P4 set interfaces fe-1/2/2 unit 21 family inet6 address 2001:db8:0:21::/64 eui-64 set interfaces lo0 unit 2 family inet6 address 2001:db8::2/128 set protocols router-advertisement interface fe-1/2/0.2 prefix 2001:db8:0:1::/64 set protocols router-advertisement interface fe-1/2/1.14 prefix 2001:db8:0:14::/64 set protocols router-advertisement interface fe-1/2/2.21 prefix 2001:db8:0:21::/64
Device R3
set interfaces fe-1/2/0 unit 10 description to-P1 set interfaces fe-1/2/0 unit 10 family inet6 address 2001:db8:0:9::/64 eui-64 set interfaces fe-1/2/1 unit 13 description to-P2 set interfaces fe-1/2/1 unit 13 family inet6 address 2001:db8:0:14::/64 eui-64 set interfaces fe-1/2/2 unit 17 description to-P4 set interfaces fe-1/2/2 unit 17 family inet6 address 2001:db8:0:17::/64 eui-64 set interfaces lo0 unit 3 family inet6 address 2001:db8::3/128 set protocols router-advertisement interface fe-1/2/0.10 prefix 2001:db8:0:9::/64 set protocols router-advertisement interface fe-1/2/1.13 prefix 2001:db8:0:14::/64 set protocols router-advertisement interface fe-1/2/2.17 prefix 2001:db8:0:17::/64
Device R4
set interfaces fe-1/2/0 unit 6 description to-P1 set interfaces fe-1/2/0 unit 6 family inet6 address 2001:db8:0:5::/64 eui-64 set interfaces fe-1/2/1 unit 18 description to-P3 set interfaces fe-1/2/1 unit 18 family inet6 address 2001:db8:0:17::/64 eui-64 set interfaces fe-1/2/2 unit 22 description to-P2 set interfaces fe-1/2/2 unit 22 family inet6 address 2001:db8:0:21::/64 eui-64 set interfaces lo0 unit 4 family inet6 address 2001:db8::4/128 set protocols router-advertisement interface fe-1/2/0.6 prefix 2001:db8:0:5::/64 set protocols router-advertisement interface fe-1/2/1.18 prefix 2001:db8:0:17::/64 set protocols router-advertisement interface fe-1/2/2.22 prefix 2001:db8:0:21::/64
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode in the CLI User Guide.
To configure a IPv6 neighbor discovery:
Configure the network interfaces.
This example shows multiple loopback interface addresses to simulate attached networks.
[edit interfaces] user@R1# set fe-1/2/0 unit 1 description to-P2 user@R1# set fe-1/2/0 unit 1 family inet6 address 2001:db8:0:1::/64 eui-64 user@R1# set fe-1/2/1 unit 5 description to-P4 user@R1# set fe-1/2/1 unit 5 family inet6 address 2001:db8:0:5::/64 eui-64 user@R1# set fe-1/2/2 unit 9 description to-P3 user@R1# set fe-1/2/2 unit 9 family inet6 address 2001:db8:0:9::/64 eui-64 user@R1# set lo0 unit 1 family inet6 address 2001:db8::1/128
Enable neighbor discovery.
[edit protocols router-advertisement] user@R1# set interface fe-1/2/0.1 prefix 2001:db8:0:1::/64 user@R1# set interface fe-1/2/1.5 prefix 2001:db8:0:5::/64 user@R1# set interface fe-1/2/2.9 prefix 2001:db8:0:9::/64
Results
From configuration mode, confirm your configuration
by entering the show interfaces and show protocols commands. If the output does not display the intended configuration,
repeat the configuration instructions in this example to correct it.
user@R1# show interfaces
fe-1/2/0 {
unit 1 {
description to-P2;
family inet6 {
address 2001:db8:0:1::/64 {
eui-64;
}
}
}
}
fe-1/2/1 {
unit 5 {
description to-P4;
family inet6 {
address 2001:db8:0:5::/64 {
eui-64;
}
}
}
}
fe-1/2/2 {
unit 9 {
description to-P3;
family inet6 {
address 2001:db8:0:9::/64 {
eui-64;
}
}
}
}
lo0 {
unit 1 {
family inet6 {
address 2001:db8::1/128;
}
}
}
user@R1# show protocols
router-advertisement {
interface fe-1/2/0.1 {
prefix 2001:db8:0:1::/64;
}
interface fe-1/2/1.5 {
prefix 2001:db8:0:5::/64;
}
interface fe-1/2/2.9 {
prefix 2001:db8:0:9::/64;
}
}
If you are done configuring the device, enter commit from configuration mode.
Verification
To confirm that the configuration is working properly, perform this task:
- Checking the Interfaces
- Pinging the Interfaces
- Checking the IPv6 Neighbor Cache
- Verifying IPv6 Router Advertisements
- Tracing Neighbor Discovery Events
Checking the Interfaces
Purpose
Verify that the interfaces are up, and view the assigned EUI-64 addresses.
Action
From operational mode, enter the show interfaces
terse command.
user@R1> show interfaces terse
Interface Admin Link Proto Local Remote
fe-1/2/0
fe-1/2/0.1 up up inet6 2001:db8:0:1:2a0:a514:0:14c/64
fe80::2a0:a514:0:14c/64
fe-1/2/1.5 up up inet6 2001:db8:0:5:2a0:a514:0:54c/64
fe80::2a0:a514:0:54c/64
fe-1/2/2.9 up up inet6 2001:db8:0:9:2a0:a514:0:94c/64
fe80::2a0:a514:0:94c/64
lo0
lo0.1 up up inet6 2001:db8::1
fe80::2a0:a50f:fc56:14cMeaning
The output shows that all interfaces are configured
with the IPv6 (inet6) address family. Each IPv6-enabled interface
has two IPv6 addresses; one link-local address, and one global address.
The global addresses match those shown in Figure 1. Junos OS automatically creates a link-local address for
any interface that is enabled for IPv6 operation. All link-local addresses
begin with the fe80::/64 prefix. The host portion of the address is
a full 64 bits long and matches the link-local interface identifier.
When an interface address is configured using the eui-64 statement, its interface identifier matches the interface identifier
of the link-local address. This is because link-local addresses are
coded according to the EUI-64 specification.
Pinging the Interfaces
Purpose
Verify connectivity between the directly connected interfaces.
Action
Determine the remote router’s IPv6 interface address.
On Device R2, run the
show interfaces tersecommand for the interface that is directly connected to Device R1, and copy the global address into the capture buffer of your terminal emulator.user@R2> show interfaces fe-1/2/0.2 terse Interface Admin Link Proto Local Remote fe-1/2/0.2 up up inet6 2001:db8:0:1:2a0:a514:0:24c/64 fe80::2a0:a514:0:24c/64On Device R1, run the
pingcommand, using the global address that you copied.user@R1> ping 2001:db8:0:1:2a0:a514:0:24c PING6(56=40+8+8 bytes) 2001:db8:0:1:2a0:a514:0:14c --> 2001:db8:0:1:2a0:a514:0:24c 16 bytes from 2001:db8:0:1:2a0:a514:0:24c, icmp_seq=0 hlim=64 time=20.412 ms 16 bytes from 2001:db8:0:1:2a0:a514:0:24c, icmp_seq=1 hlim=64 time=18.897 ms 16 bytes from 2001:db8:0:1:2a0:a514:0:24c, icmp_seq=2 hlim=64 time=1.389 ms
Meaning
Junos OS uses the same ping command for both IPv4 and IPv6 testing. The lack of any interior gateway protocol (IGP) in the network limits the ping testing to directly-connected neighbors. Repeat the ping test for other directly connected neighbors.
Checking the IPv6 Neighbor Cache
Purpose
Display information about the IPv6 neighbors.
After conducting ping testing, you can find an entries for interface addresses in the IPv6 neighbor cache.
Action
From operational mode, enter the show ipv6 neighbors command.
user@R1> show ipv6 neighbors IPv6 Address Linklayer Address State Exp Rtr Secure Interface 2001:db8:0:1:2a0:a514:0:24c 00:05:85:8f:c8:bd stale 546 yes no fe-1/2/0.1 fe80::2a0:a514:0:24c 00:05:85:8f:c8:bd stale 258 yes no fe-1/2/0.1 fe80::2a0:a514:0:64c 00:05:85:8f:c8:bd stale 111 yes no fe-1/2/1.5 fe80::2a0:a514:0:a4c 00:05:85:8f:c8:bd stale 327 yes no fe-1/2/2.9
Meaning
In IPv6, the Address Resolution Protocol (ARP) has
been replaced by the Neighbor Discovery Protocol (NDP). The IPv4 command show arp is replaced by the IPv6 command show ipv6 neighbors. The key pieces of information displayed by this command are the
IP address, the MAC (Link Layer) address, and the interface.
Verifying IPv6 Router Advertisements
Purpose
Confirm that devices can be added to the network using SLAAC by ensuring that router advertisements are working properly.
Action
From operational mode, enter the show ipv6 router-advertisement command.
user@R1> show ipv6 router-advertisement
Interface: fe-1/2/0.1
Advertisements sent: 37, last sent 00:01:41 ago
Solicits received: 0
Advertisements received: 38
Advertisement from fe80::2a0:a514:0:24c, heard 00:05:46 ago
Managed: 0
Other configuration: 0
Reachable time: 0 ms
Default lifetime: 1800 sec
Retransmit timer: 0 ms
Current hop limit: 64
Prefix: 2001:db8:0:1::/64
Valid lifetime: 2592000 sec
Preferred lifetime: 604800 sec
On link: 1
Autonomous: 1
Interface: fe-1/2/1.5
Advertisements sent: 36, last sent 00:05:49 ago
Solicits received: 0
Advertisements received: 37
Advertisement from fe80::2a0:a514:0:64c, heard 00:00:54 ago
Managed: 0
Other configuration: 0
Reachable time: 0 ms
Default lifetime: 1800 sec
Retransmit timer: 0 ms
Current hop limit: 64
Prefix: 2001:db8:0:5::/64
Valid lifetime: 2592000 sec
Preferred lifetime: 604800 sec
On link: 1
Autonomous: 1
Interface: fe-1/2/2.9
Advertisements sent: 36, last sent 00:01:37 ago
Solicits received: 0
Advertisements received: 38
Advertisement from fe80::2a0:a514:0:a4c, heard 00:01:00 ago
Managed: 0
Other configuration: 0
Reachable time: 0 ms
Default lifetime: 1800 sec
Retransmit timer: 0 ms
Current hop limit: 64
Prefix: 2001:db8:0:9::/64
Valid lifetime: 2592000 sec
Preferred lifetime: 604800 sec
On link: 1
Autonomous: 1Meaning
The output shows that router advertisements are being sent and received on Device R1’s interfaces, indicating that both Device R1 and its directly connected neighbors are configured to generate router-advertisements.
Tracing Neighbor Discovery Events
Purpose
Perform additional validation by tracing router advertisements.
Action
Configure trace operations.
[edit protocols router-advertisement traceoptions] user@R1# set file ipv6-nd-trace user@R1# set traceoptions flag all user@R1# commit
Run the
show logcommand.user@R1> show log ipv6-nd-trace Mar 29 14:07:16 trace_on: Tracing to "/var/log/P1/ipv6-nd-trace" started Mar 29 14:07:16.287229 background dispatch running job ipv6_ra_delete_interface_config_job for task Router-Advertisement Mar 29 14:07:16.287452 task_job_delete: delete background job ipv6_ra_delete_interface_config_job for task Router-Advertisement Mar 29 14:07:16.287505 background dispatch completed job ipv6_ra_delete_interface_config_job for task Router-Advertisement Mar 29 14:07:16.288288 ipv6_ra_iflchange(Router-Advertisement): ifl 0xb904378 ifl fe-1/2/2.9 104 change 0, intf 0xba140d8 Mar 29 14:07:16.288450 ipv6_ra_iflchange(Router-Advertisement): ifl 0xb904250 ifl fe-1/2/0.1 85 change 0, intf 0xba14000 Mar 29 14:07:16.288656 ipv6_ra_iflchange(Router-Advertisement): ifl 0xb9044a0 ifl fe-1/2/1.5 80 change 0, intf 0xba1406c Mar 29 14:07:16.289293 ipv6_ra_ifachange(Router-Advertisement): ifa 0xba002bc fe80::2a0:a514:0:54c ifl fe-1/2/1.5 80 change 0, intf 0xba1406c Mar 29 14:07:16.289358 -- nochange/add Mar 29 14:07:16.289624 ipv6_ra_ifachange(Router-Advertisement): ifa 0xba00230 2001:db8:0:5:2a0:a514:0:54c ifl fe-1/2/1.5 80 change 0, intf 0xba1406c Mar 29 14:07:16.289682 -- nochange/add Mar 29 14:07:16.289950 ipv6_ra_ifachange(Router-Advertisement): ifa 0xba001a4 fe80::2a0:a514:0:14c ifl fe-1/2/0.1 85 change 0, intf 0xba14000 Mar 29 14:07:16.290009 -- nochange/add Mar 29 14:07:16.290302 ipv6_ra_ifachange(Router-Advertisement): ifa 0xba00118 2001:db8:0:1:2a0:a514:0:14c ifl fe-1/2/0.1 85 change 0, intf 0xba14000 Mar 29 14:07:16.290365 -- nochange/add Mar 29 14:07:16.290634 ipv6_ra_ifachange(Router-Advertisement): ifa 0xba003d4 fe80::2a0:a514:0:94c ifl fe-1/2/2.9 104 change 0, intf 0xba140d8 Mar 29 14:07:16.290694 -- nochange/add Mar 29 14:07:16.290958 ipv6_ra_ifachange(Router-Advertisement): ifa 0xba00348 2001:db8:0:9:2a0:a514:0:94c ifl fe-1/2/2.9 104 change 0, intf 0xba140d8 Mar 29 14:07:16.291017 -- nochange/add Mar 29 14:07:20.808516 task_job_create_foreground: create job ipv6 ra for task Router-Advertisement Mar 29 14:07:20.808921 foreground dispatch running job ipv6 ra for task Router-Advertisement Mar 29 14:07:20.809027 ipv6_ra_send_advertisement: sending advertisement for ifl 104 to ff02::1 Mar 29 14:07:20.809087 (4810916) sending advertisement for ifl 104 Mar 29 14:07:20.809170 ifa 0xba00348 2001:db8:0:9:2a0:a514:0:94c/64 Mar 29 14:07:20.809539 --> sent 56 bytes Mar 29 14:07:20.809660 task_timer_reset: reset Router-Advertisement_ipv6ra Mar 29 14:07:20.809725 task_timer_set_oneshot_latest: timer Router-Advertisement_ipv6ra interval set to 7:07 Mar 29 14:07:20.809772 foreground dispatch completed job ipv6 ra for task Router-Advertisement