dhcpv6rsra

### DHCPv6 Router Solicitation and Router Advertisement Configuration

#### Understanding the Mechanism

A Personal Computer (PC) using Stateless Address Autoconfiguration (SLAAC) acquires the IPv6 prefix and prefix length from a router. Upon booting, this device transmits an RS (Router Solicitation) message to notify routers of its need for network configuration details. In response, a router broadcasts an RA (Router Advertisement) message containing necessary information such as prefixes and flags indicating whether additional configurations like DNS servers can be obtained via DHCPv6 or not[^1].

For enabling RAs on Cisco devices specifically:

ipv6 unicast-routing
interface GigabitEthernet0/0
 ipv6 nd ra-interval 200

The `ipv6 unicast-routing` command enables IPv6 routing globally while specifying intervals at which unsolicited advertisements occur through `ipv6 nd ra-interval`.

To ensure hosts recognize they require further configuration beyond what's provided within these packets—such as addresses for Domain Name System (DNS)—the following setting must also appear under relevant interfaces' settings:

ipv6 nd other-config-flag

This flag prompts clients to seek out supplementary parameters using Stateful DHCPv6 after receiving basic connectivity data.

#### Troubleshooting Common Issues

When encountering issues where hosts fail to obtain full networking capabilities despite proper SLAAC setup, verify presence of both aforementioned commands (`ipv6 unicast-routing`, `ipv6 nd other-config-flag`) alongside ensuring no firewall rules block ICMPv6 traffic types essential for functioning correctly including Neighbor Discovery Protocol messages.

Additionally, confirm that any intermediary security appliances between end-devices and their default gateway do not interfere unintentionally with critical packet exchanges needed during initialization phases.

--related questions--

1. How does one configure a Linux system to request more than just addressing information when utilizing SLAAC?
2. What specific tools exist within Windows operating systems to diagnose problems related to obtaining complete network settings over IPv6 links?
3. Can you provide examples demonstrating how different vendors implement support for sending extended configuration hints inside Router Advertisements?