### Calculate IPv6 address from prefix and MAC

Source: https://github.com/radvd-project/radvd/blob/master/INTRO.html

Example of how a host derives an IPv6 address using an announced prefix and a hardware MAC address.

```text
   Announced prefix:    2001:db8:0:1::

   MAC address:         00:07:E9:7B:02:59

   EUI-64 identifier:   0207:e9ff:fe7b:259

   Configured address:  2001:db8:0:1:207:e9ff:fe7b:259
```

--------------------------------

### Spec File Install Locations

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Example of defining installation directories in an RPM spec file. These can be overridden by rpmbuild.

```makefile
bindir=/usr/local/bin
libdir=/usr/local/lib
sysconfdir=/etc
mandir=/usr/local/man

ifdef RPM_DOC_DIR
sixdocdir = $(RPM_BUILD_ROOT)/$(RPM_DOC_DIR)/$(RPM_PACKAGE_NAME)-$(RPM_PACKAGE_VERSION)
else
sixdocdir = /usr/local/doc/sixpack
endif
```

--------------------------------

### Configure Specific Route Advertisement

Source: https://context7.com/radvd-project/radvd/llms.txt

Guide hosts to use the router for specific destination networks with defined preferences.

```conf
# /etc/radvd.conf - Route information
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };

    # Advertise specific route to remote network
    route 2001:db8:remote::/48
    {
        # Route preference: low, medium, or high
        AdvRoutePreference high;

        # Route lifetime (default: 3*MaxRtrAdvInterval)
        AdvRouteLifetime 3600;

        # Remove route from clients on shutdown
        RemoveRoute on;
    };

    # Multiple routes with different preferences
    route 2001:db8:backup::/48
    {
        AdvRoutePreference low;
        AdvRouteLifetime 1800;
    };
};
```

--------------------------------

### Build package archives

Source: https://github.com/radvd-project/radvd/blob/master/RELEASE-PROCESS.md

Execute the build pipeline to generate release archives.

```bash
./autogen-container.sh
./configure
make packages
```

--------------------------------

### Build and Sign RPM Packages

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Commands to build an RPM from a source tarball, sign it, and query package information.

```bash
$ rpmbuild -ts radvd-1.7.tar.gz
$ rpm --addsign rpm/SRPMS/radvd-1.7-1.src.rpm
$ rpm -qip rpm/SRPMS/radvd-1.7-1.src.rpm
```

--------------------------------

### Create GitHub release

Source: https://github.com/radvd-project/radvd/blob/master/RELEASE-PROCESS.md

Use the GitHub CLI to publish the release and upload generated artifacts.

```bash
gh release create v${VERSION} radvd-${VERSION}.tar.{xz,gz}{,.asc,.sha256,.sha512}`
```

--------------------------------

### Create RPM Build Directories

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Creates the standard directory structure required for RPM building within a user's home directory.

```bash
$ mkdir ~/rpm ~/rpm/BUILD ~/rpm/RPMS ~/rpm/RPMS/i386 ~/rpm/RPMS/i686 ~/rpm/RPMS/noarch ~/rpm/SOURCES ~/rpm/SPECS ~/rpm/SRPMS ~/rpm/tmp
```

--------------------------------

### Configure RPM Build Environment

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Sets up the ~/.rpmmacros file to define the top-level build directory and temporary path for RPM building.

```bash
%_topdir               /home/rpmbuild/rpm
%_tmppath              /home/rpmbuild/rpm/tmp
```

--------------------------------

### Dynamic Interface Configuration

Source: https://context7.com/radvd-project/radvd/llms.txt

Configure radvd to handle interfaces that may not exist at startup or may be dynamically enabled/disabled using 'IgnoreIfMissing on'.

```conf
# /etc/radvd.conf - Dynamic interfaces
interface wlan0
{
    # Don't fail if interface doesn't exist at startup
    IgnoreIfMissing on;

    AdvSendAdvert on;

    # Shorter intervals for mobile scenarios
    MaxRtrAdvInterval 30;
    MinRtrAdvInterval 10;

    prefix 2001:db8:wifi::/64
    {
        AdvOnLink on;
        AdvAutonomous on;

        # Shorter lifetimes for dynamic networks
        AdvValidLifetime 600;
        AdvPreferredLifetime 300;
    };
};

interface tun0
{
    IgnoreIfMissing on;
    AdvSendAdvert on;

    prefix 2001:db8:vpn::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };
};
```

--------------------------------

### Configure Basic Interface Advertisements

Source: https://context7.com/radvd-project/radvd/llms.txt

Enable router advertisements on a specific interface and define a prefix for SLAAC.

```text
# /etc/radvd.conf - Basic configuration
interface eth0
{
    # Enable sending router advertisements
    AdvSendAdvert on;

    # Advertise a /64 prefix for SLAAC
    prefix 2001:db8:1::/64
    {
        # Prefix can be used for on-link determination
        AdvOnLink on;

        # Prefix can be used for autonomous address configuration
        AdvAutonomous on;
    };
};
```

--------------------------------

### Configure Base Interface Prefix Generation

Source: https://context7.com/radvd-project/radvd/llms.txt

Generate a /64 prefix by combining a prefix with the IPv6 address of another interface.

```conf
# /etc/radvd.conf - Base interface configuration
interface eth1
{
    AdvSendAdvert on;

    prefix 2001:db8::/64
    {
        AdvOnLink on;
        AdvAutonomous on;

        # Combine with IPv6 address from eth0 to create prefix
        Base6Interface eth0;
    };
};
```

--------------------------------

### RPM Build Commands

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Commands to copy a spec file, archive source code, and build an RPM package.

```bash
$ cp myspec.spec ~/rpm/SPECS/
$ tar -zcvf ~/rpm/SOURCES/mypackagename-myversionnumber.tar.gz mypackagename-myversionnumber
$ rpmbuild -ba ~/rpm/SPECS/myspec.spec
```

--------------------------------

### Send Public GPG Key to Keyserver

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Command to upload your public GPG key to a keyserver, making it accessible to others for verification purposes.

```bash
$ gpg --keyserver pgp.mit.edu --send-key "USERID"
```

--------------------------------

### Update configure.ac version

Source: https://github.com/radvd-project/radvd/blob/master/RELEASE-PROCESS.md

Automated commands to extract the version from the CHANGES file and update the AC_INIT macro in configure.ac.

```bash
export VERSION="$(grep Release CHANGES | head -1 | sed s/'.*Release v'//g)"
echo "New version identifier is: $VERSION"
sed -i -e "/^AC_INIT/s,\[.*\] ,[$VERSION],g" configure.ac
```

--------------------------------

### RPM Macros for GPG Signing

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Configuration for ~/.rpmmacros to specify GPG as the signing method and set the GPG user ID and binary path.

```bash
%_signature gpg
%_gpg_name USERID
%_gpgbin /usr/bin/gpg
```

--------------------------------

### Execute RADVD via Command Line

Source: https://context7.com/radvd-project/radvd/llms.txt

Run the radvd daemon with various flags for debugging, logging, and security configuration.

```bash
# Start radvd with default configuration
radvd

# Test configuration file for syntax errors
radvd --configtest

# Run with custom configuration file
radvd --config /etc/radvd/custom.conf

# Run in foreground without daemonizing (useful for debugging)
radvd --nodaemon

# Enable debugging (levels 1-5, higher = more verbose)
radvd --debug 3

# Run as unprivileged user (recommended for security)
radvd --username radvd --pidfile /var/run/radvd/radvd.pid

# Use different logging methods
radvd --logmethod syslog
radvd --logmethod logfile --logfile /var/log/radvd.log
radvd --logmethod stderr

# Combined example: test config, run as user, with logging
radvd --configtest --config /etc/radvd.conf
radvd --config /etc/radvd.conf --username radvd --logmethod syslog --pidfile /var/run/radvd/radvd.pid

# Display version
radvd --version

# Display help
radvd --help
```

--------------------------------

### List GPG Signatures

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Command to display a list of your GPG keys and their signatures. Useful for verifying key details.

```bash
$ gpg --list-sigs
```

--------------------------------

### Manage radvd Service with systemd

Source: https://context7.com/radvd-project/radvd/llms.txt

Standard systemd commands for controlling the radvd daemon. Includes configuration testing and log access.

```bash
sudo systemctl start radvd

sudo systemctl stop radvd

sudo systemctl restart radvd

sudo systemctl enable radvd

sudo systemctl status radvd

sudo journalctl -u radvd

sudo journalctl -u radvd -f

sudo systemctl reload radvd
# Or send SIGHUP directly:
sudo kill -HUP $(cat /var/run/radvd/radvd.pid)

sudo radvd --configtest
```

--------------------------------

### Configure Auto-detected Prefixes

Source: https://context7.com/radvd-project/radvd/llms.txt

Automatically advertise global prefixes on an interface while optionally ignoring specific ones.

```conf
# /etc/radvd.conf - Auto-detect prefixes
interface eth0
{
    AdvSendAdvert on;

    # Automatically advertise all global prefixes on this interface
    prefix ::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
        AdvValidLifetime 86400;
        AdvPreferredLifetime 14400;
    };

    # Optionally ignore certain auto-detected prefixes
    autoignoreprefixes
    {
        2001:db8:ignore::/64;
        fd00:private::/64;
    };
};
```

--------------------------------

### Configure radvd interface and prefix

Source: https://github.com/radvd-project/radvd/blob/master/INTRO.html

Basic configuration block for enabling router advertisements on a specific network interface.

```text
interface eth0
{
        AdvSendAdvert on;
        prefix 2001:db8:0:1::/64
        {
                AdvOnLink on;
                AdvAutonomous on;
        };
};
```

--------------------------------

### Configure 6to4 Prefix Generation

Source: https://context7.com/radvd-project/radvd/llms.txt

Automatically generate and advertise 6to4 prefixes based on the IPv4 address of another interface.

```conf
# /etc/radvd.conf - 6to4 configuration
interface eth1
{
    AdvSendAdvert on;

    # Advertise at least every 30 seconds for dynamic addresses
    MaxRtrAdvInterval 30;
    MinRtrAdvInterval 10;

    # 6to4 prefix - first 48 bits replaced with 2002:IPv4addr
    # SLA ID is 5678 in this example
    prefix 0:0:0:5678::/64
    {
        AdvOnLink on;
        AdvAutonomous on;

        # Use IPv4 address from ppp0 to form 6to4 prefix
        Base6to4Interface ppp0;

        # Short lifetimes for dynamic IPv4 addresses
        AdvValidLifetime 300;
        AdvPreferredLifetime 120;
    };
};
```

--------------------------------

### Check version consistency

Source: https://github.com/radvd-project/radvd/blob/master/RELEASE-PROCESS.md

Commands to verify the current version identifier in configuration and changelog files.

```bash
grep AC_INIT configure.ac | cut -d[ -f 2 | cut -d] -f 1
grep Release CHANGES | head -1
```

--------------------------------

### Configure DHCPv6 Integration Flags

Source: https://context7.com/radvd-project/radvd/llms.txt

Set managed and other configuration flags to instruct hosts to use DHCPv6 for address and network configuration.

```text
interface eth0
{
    AdvSendAdvert on;

    # Tell hosts to use DHCPv6 for address configuration
    # (stateful DHCPv6 in addition to SLAAC)
    AdvManagedFlag on;

    # Tell hosts to use DHCPv6 for other configuration
    # (DNS, NTP, etc. - commonly used with SLAAC)
    AdvOtherConfigFlag on;

    # MTU to advertise (0 = don't advertise)
    AdvLinkMTU 1500;

    # Default hop limit for outgoing packets
    AdvCurHopLimit 64;

    # Neighbor reachability time (milliseconds, 0 = unspecified)
    AdvReachableTime 0;

    # Neighbor solicitation retransmit time (milliseconds)
    AdvRetransTimer 0;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };
};
```

--------------------------------

### Clean Docker environment

Source: https://github.com/radvd-project/radvd/blob/master/RELEASE-PROCESS.md

Remove the existing build container image to ensure a clean build environment.

```bash
docker rmi radvd-autogen:latest
```

--------------------------------

### Commit and tag release

Source: https://github.com/radvd-project/radvd/blob/master/RELEASE-PROCESS.md

Create a signed commit and a signed git tag for the new release version.

```bash
git commit -s -m "Release ${VERSION}" CHANGES configure.ac
git tag -s v${VERSION} -m "$VERSION"
```

--------------------------------

### Configure Unicast-Only Links

Source: https://context7.com/radvd-project/radvd/llms.txt

Set up radvd for non-broadcast links such as ISATAP or point-to-point connections.

```conf
# /etc/radvd.conf - Unicast-only mode
interface isatap0
{
    AdvSendAdvert on;

    # Enable for non-multicast links
    UnicastOnly on;

    # Respond to solicitations with unicast RAs (RFC 7772)
    AdvRASolicitedUnicast on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };
};
```

--------------------------------

### Export Public GPG Key

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Command to export your public GPG key into an ASCII-armored file. This key can be shared with others for verification.

```bash
$ gpg --armor --export "USERID" > my.key.file.asc
```

--------------------------------

### Sign RPM Package

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Command to digitally sign an RPM package using GPG. This is a required step for submitting packages to Fedora.

```bash
$ rpm --addsign name_of_rpm_package
```

--------------------------------

### 6LoWPAN Border Router Configuration (ABRO)

Source: https://context7.com/radvd-project/radvd/llms.txt

Configure radvd as an Authoritative Border Router (ABRO) for 6LoWPAN networks using RFC 6775. Requires UnicastOnly on and AdvCurHopLimit set to 255.

```conf
# /etc/radvd.conf - 6LoWPAN ABRO
interface lowpan0
{
    AdvSendAdvert on;

    # Required for 6LoWPAN
    UnicastOnly on;

    # Set hop limit to 255 for ND security
    AdvCurHopLimit 255;

    prefix 2001:db8:100:f101::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
        AdvRouterAddr on;
    };

    # Authoritative Border Router Option
    abro fe80::a200:0:0:1/64
    {
        # Version numbers for border router info set
        AdvVersionLow 10;
        AdvVersionHigh 2;

        # Validity time for border router information
        AdvValidLifetime 2;
    };
};
```

--------------------------------

### Set Advertisement Timing Intervals

Source: https://context7.com/radvd-project/radvd/llms.txt

Adjust the frequency of unsolicited router advertisements and router preference settings.

```text
# /etc/radvd.conf - Advertisement timing
interface eth0
{
    AdvSendAdvert on;

    # Maximum time between unsolicited RAs (4-65535 seconds)
    MaxRtrAdvInterval 600;

    # Minimum time between unsolicited RAs
    MinRtrAdvInterval 200;

    # Minimum delay between multicast RAs
    MinDelayBetweenRAs 3;

    # Default router lifetime (0 = not a default router)
    AdvDefaultLifetime 1800;

    # Router preference for default router selection
    AdvDefaultPreference medium;  # low, medium, or high

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };
};
```

--------------------------------

### GPG Key Generation

Source: https://github.com/radvd-project/radvd/wiki/Building-RPMs

Command to generate a new GPG secret key for signing packages. This process will prompt for user information and a password.

```bash
$ gpg --gen-key
```

--------------------------------

### Configure DNS Server Advertisement (RDNSS)

Source: https://context7.com/radvd-project/radvd/llms.txt

Advertise recursive DNS server addresses to hosts using the RFC 8106 RDNSS option.

```conf
# /etc/radvd.conf - DNS servers
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };

    # Single DNS server
    RDNSS 2001:db8:1::53
    {
        # Lifetime for DNS server validity (default: 3*MaxRtrAdvInterval)
        AdvRDNSSLifetime 1800;
    };

    # Multiple DNS servers (up to 127 addresses per block)
    RDNSS 2001:db8:1::53 2001:db8:1::54 2001:4860:4860::8888
    {
        AdvRDNSSLifetime 1800;

        # Remove DNS servers from clients on shutdown
        FlushRDNSS on;
    };
};
```

--------------------------------

### Captive Portal Configuration

Source: https://context7.com/radvd-project/radvd/llms.txt

Advertise a Captive Portal API URL using RFC 8908 for networks with captive portals. Includes RDNSS configuration.

```conf
# /etc/radvd.conf - Captive portal
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };

    # Captive Portal API URL (RFC 8908/8910)
    AdvCaptivePortalAPI "https://portal.example.net/api/capport.json";

    RDNSS 2001:db8:1::53
    {
        AdvRDNSSLifetime 1800;
    };
};
```

--------------------------------

### Configure Decrementing Lifetimes for DHCPv6-PD

Source: https://context7.com/radvd-project/radvd/llms.txt

Use this configuration to enable lifetime decrementing for delegated prefixes. Reset the timers using SIGUSR1 when the prefix is renewed.

```text
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:delegated::/64
    {
        AdvOnLink on;
        AdvAutonomous on;

        # Initial lifetimes from DHCPv6 delegation
        AdvValidLifetime 86400;
        AdvPreferredLifetime 43200;

        # Decrement lifetimes with each RA
        # Reset with SIGUSR1 when prefix is renewed
        DecrementLifetimes on;
    };
};
```

--------------------------------

### Validate changes

Source: https://github.com/radvd-project/radvd/blob/master/RELEASE-PROCESS.md

Review modifications to version-controlled files before committing.

```bash
git diff CHANGES configure.ac
```

--------------------------------

### Mobile IPv6 Home Agent Configuration

Source: https://context7.com/radvd-project/radvd/llms.txt

Configure radvd to act as a Mobile IPv6 Home Agent. Ensure AdvHomeAgentFlag and AdvHomeAgentInfo are enabled.

```conf
# /etc/radvd.conf - Mobile IPv6 Home Agent
interface eth0
{
    AdvSendAdvert on;

    # Enable Home Agent flag
    AdvHomeAgentFlag on;

    # Include Home Agent Information option
    AdvHomeAgentInfo on;

    # Home Agent lifetime (max 65520 seconds)
    HomeAgentLifetime 1800;

    # Home Agent preference (higher = more preferred)
    HomeAgentPreference 10;

    # Enable Mobile Router support (NEMO Basic)
    AdvMobRtrSupportFlag on;

    # Include Advertisement Interval option
    AdvIntervalOpt on;

    # Use interface address instead of prefix for Mobile IPv6
    prefix 2001:db8:1::1/64
    {
        AdvOnLink on;
        AdvAutonomous on;

        # Required for Mobile IPv6 movement detection
        AdvRouterAddr on;
    };
};
```

--------------------------------

### NAT64 Prefix Advertisement

Source: https://context7.com/radvd-project/radvd/llms.txt

Advertise a NAT64 prefix to allow IPv6-only networks to access IPv4 resources. Supports well-known and custom prefixes.

```conf
# /etc/radvd.conf - NAT64 configuration
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };

    # NAT64 prefix (well-known prefix 64:ff9b::/96)
    nat64prefix 64:ff9b::/96
    {
        # Lifetime (max 65528, rounded to multiple of 8)
        AdvValidLifetime 1800;
    };

    # Custom NAT64 prefix (valid lengths: /32, /40, /48, /56, /64, /96)
    nat64prefix 2001:db8:64::/96
    {
        AdvValidLifetime 3600;
    };

    # DNS server for NAT64 environment
    RDNSS 2001:db8:1::64
    {
        AdvRDNSSLifetime 1800;
    };
};
```

--------------------------------

### Define Prefix Lifetimes

Source: https://context7.com/radvd-project/radvd/llms.txt

Specify valid and preferred lifetimes for prefixes to control how long hosts retain address configurations.

```text
# /etc/radvd.conf - Prefix lifetimes
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;

        # Time prefix is valid for on-link determination (default: 86400)
        AdvValidLifetime 86400;        # 1 day

        # Time addresses remain preferred (default: 14400)
        AdvPreferredLifetime 14400;    # 4 hours

        # Use 'infinity' for permanent prefixes
        # AdvValidLifetime infinity;
        # AdvPreferredLifetime infinity;
    };

    # Short-lived prefix for dynamic scenarios
    prefix 2001:db8:2::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
        AdvValidLifetime 300;          # 5 minutes
        AdvPreferredLifetime 120;      # 2 minutes
    };
};
```

--------------------------------

### Configure Client Restrictions

Source: https://context7.com/radvd-project/radvd/llms.txt

Restrict router advertisements to specific clients using unicast addresses.

```conf
# /etc/radvd.conf - Client restrictions
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };

    # Only send RAs to these specific clients
    clients
    {
        fe80::21f:16ff:fe06:3aab;
        fe80::21d:72ff:fe96:aaff;
        fe80::1234:5678:abcd:ef01;

        # Prefix with ! to explicitly ignore a client
        !fe80::bad:client:addr:here;
    };

    # Optionally allow responding to RS from unknown clients
    # while still only sending periodic RAs to listed clients
    UnrestrictedUnicast on;
};
```

--------------------------------

### Shutdown Behavior Configuration

Source: https://context7.com/radvd-project/radvd/llms.txt

Configure radvd's behavior on shutdown, including sending RAs with zero lifetime, deprecating prefixes, and removing routes/DNS entries.

```conf
# /etc/radvd.conf - Shutdown behavior
interface eth0
{
    AdvSendAdvert on;

    # Send RA with zero lifetime on shutdown (removes router)
    RemoveAdvOnExit on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;

        # Deprecate prefix on shutdown (set preferred lifetime to 0)
        DeprecatePrefix on;
    };

    route 2001:db8:remote::/48
    {
        AdvRoutePreference medium;

        # Remove route on shutdown
        RemoveRoute on;
    };

    RDNSS 2001:db8:1::53
    {
        # Remove DNS server on shutdown
        FlushRDNSS on;
    };

    DNSSL example.com
    {
        # Remove search list on shutdown
        FlushDNSSL on;
    };
};
```

--------------------------------

### Control radvd with Unix Signals

Source: https://context7.com/radvd-project/radvd/llms.txt

Send signals to the radvd process to reload configuration, reset lifetimes, or shut down gracefully.

```bash
kill -HUP $(cat /var/run/radvd/radvd.pid)

kill -USR1 $(cat /var/run/radvd/radvd.pid)

kill -TERM $(cat /var/run/radvd/radvd.pid)

kill -TERM $(cat /var/run/radvd/radvd.pid)
kill -TERM $(cat /var/run/radvd/radvd.pid)
```

--------------------------------

### RA Source Address Configuration

Source: https://context7.com/radvd-project/radvd/llms.txt

Configure specific source addresses for Router Advertisements, useful for VRRP or failover scenarios. Includes AdvSourceLLAddress option.

```conf
# /etc/radvd.conf - Custom RA source address
interface eth0
{
    AdvSendAdvert on;

    # Include link-layer address in RA
    AdvSourceLLAddress on;

    # Specify acceptable source addresses (for VRRP/failover)
    AdvRASrcAddress
    {
        fe80::1;                    # Virtual router address
        fe80::21f:16ff:fe06:3aab;   # Physical address
    };

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };
};
```

--------------------------------

### Monitor Router Advertisements with radvdump

Source: https://context7.com/radvd-project/radvd/llms.txt

Use radvdump to inspect network advertisements. Options include excluding default values and adjusting debug verbosity.

```bash
radvdump

radvdump --exclude-defaults

radvdump --debug 2

radvdump --version
```

--------------------------------

### Configure DNS Search List (DNSSL)

Source: https://context7.com/radvd-project/radvd/llms.txt

Advertise DNS search domains to hosts using the RFC 8106 DNSSL option.

```conf
# /etc/radvd.conf - DNS search list
interface eth0
{
    AdvSendAdvert on;

    prefix 2001:db8:1::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
    };

    RDNSS 2001:db8:1::53
    {
        AdvRDNSSLifetime 1800;
    };

    # DNS search domains
    DNSSL example.com corp.example.com internal.local
    {
        # Lifetime for search list validity
        AdvDNSSLLifetime 1800;

        # Remove search list from clients on shutdown
        FlushDNSSL on;
    };
};
```

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