# Host Name - System Identity and Info

> Detailed guide to configuring the host name, domain name, and static host mappings in VyOS. Includes examples for Yandex Cloud and VK Cloud.

Source: https://opennix.org/en/docs/vyos/system/vyos-host-name/


## Host Name - System Identity and Info

A host name (hostname) is a unique name that identifies a device on the network; together with the domain name it forms the fully qualified domain name (FQDN). This page describes how to configure the host name, domain name, and static name-resolution entries in VyOS. These parameters are fundamental for identifying the device on the network and for the correct operation of network services.

## Overview

The host name and domain name are used for:

- **Identifying the device** on the network
- **Building the FQDN** (Fully Qualified Domain Name)
- **Logging** and monitoring
- **Integrating with cloud platforms** (Yandex Cloud, VK Cloud)
- **DNS resolution** of local names
- **Operation of network services** (NTP, SNMP, syslog)

## Host Name

### Description

The host name is a unique label that identifies the device on the network. In VyOS the host name is used:

- In the command-line prompt (CLI prompt)
- In system logs
- In the SNMP system name
- As part of the FQDN when a domain name is set

### RFC 1123 Restrictions

The host name must comply with the RFC 1123 standard:

**Length:**
- Minimum: 1 character
- Maximum: 63 characters

**Allowed characters:**
- Latin letters: a-z, A-Z
- Digits: 0-9
- Hyphen: - (only inside the name)

**Rules:**
- Must start with a letter or digit
- Must end with a letter or digit
- May contain letters, digits, and hyphens in the middle
- Case-insensitive
- Cannot contain dots, underscores, or other special characters

### Configuration

#### Basic Setup

```bash
# Set the host name
set system host-name vyos-router

# Apply the configuration
commit
save
```

#### Examples of Valid Names

```bash
# Short name
set system host-name gateway

# Name with digits
set system host-name router01

# Name with hyphens
set system host-name core-router-01

# Maximum length (63 characters)
set system host-name vyos-production-core-router-datacenter-moscow-rack-12-unit-1
```

#### Examples of Invalid Names

```bash
# ERROR: starts with a hyphen
set system host-name -router

# ERROR: ends with a hyphen
set system host-name router-

# ERROR: contains an underscore
set system host-name vyos_router

# ERROR: contains a dot
set system host-name vyos.router

# ERROR: contains a space
set system host-name "vyos router"

# ERROR: more than 63 characters
set system host-name vyos-production-core-router-datacenter-moscow-rack-12-unit-1-mgmt
```

### Default Value

On first boot, VyOS uses the default host name:

```bash
vyos@vyos:~$
```

After the host name is configured, the CLI prompt changes:

```bash
# After setting host-name gateway
vyos@gateway:~$
```

## Domain Name

### Description

The domain name defines the DNS suffix that is appended to incomplete host names to build the FQDN (Fully Qualified Domain Name).

**How it works:**
- If only a hostname is specified without a domain, it is used as is
- If both a hostname and a domain-name are specified, the FQDN is formed as: `hostname.domain-name`
- When resolving incomplete names, the domain suffix is added automatically

### Configuration

#### Basic Setup

```bash
# Set the domain name
set system domain-name example.com

# Apply the configuration
commit
save
```

#### Full hostname + domain Configuration

```bash
# Set the host name and domain
set system host-name router01
set system domain-name corp.example.com

# Result: FQDN = router01.corp.example.com
commit
save
```

### Usage Examples

```bash
# Corporate network
set system host-name core-router
set system domain-name datacenter.moscow.mycompany.ru

# FQDN: core-router.datacenter.moscow.mycompany.ru
```

```bash
# Cloud infrastructure
set system host-name vyos-gw
set system domain-name cloud.internal

# FQDN: vyos-gw.cloud.internal
```

### Impact on Name Resolution

When a domain-name is configured, the system automatically appends it to incomplete names:

```bash
# With the setting: set system domain-name example.com

# ping server -> DNS query for server.example.com
vyos@router:~$ ping server

# For fully qualified names the suffix is not added
vyos@router:~$ ping server.otherdomain.com
```

## Static Host Mapping

### Description

Static host mappings let you create local name-to-IP-address resolution without an external DNS server. This is the equivalent of manually editing the `/etc/hosts` file, but managed through the VyOS configuration.

**Advantages:**
- Managed through the VyOS configuration (commit/rollback)
- Automatic generation of `/etc/hosts` at boot
- Support for multiple aliases per host
- Persistence across reboots

**Warning:**
Do not edit the `/etc/hosts` file manually - it is automatically overwritten from the VyOS configuration at system boot.

### Configuration

#### Basic Entry

```bash
# Add a static host mapping
set system static-host-mapping host-name server1.example.com inet 192.168.1.10

# Apply the configuration
commit
save
```

#### Entry with Aliases

```bash
# Primary entry
set system static-host-mapping host-name db-server.corp.local inet 10.0.1.100

# Adding aliases
set system static-host-mapping host-name db-server.corp.local alias database
set system static-host-mapping host-name db-server.corp.local alias db
set system static-host-mapping host-name db-server.corp.local alias mysql-primary

# Result in /etc/hosts:
# 10.0.1.100 db-server.corp.local database db mysql-primary
```

#### Multiple Hosts

```bash
# Internal servers
set system static-host-mapping host-name web01.local inet 10.0.10.11
set system static-host-mapping host-name web02.local inet 10.0.10.12
set system static-host-mapping host-name db01.local inet 10.0.10.21
set system static-host-mapping host-name cache01.local inet 10.0.10.31

# Aliases for web servers
set system static-host-mapping host-name web01.local alias www1
set system static-host-mapping host-name web02.local alias www2

# Aliases for the database
set system static-host-mapping host-name db01.local alias database
set system static-host-mapping host-name db01.local alias postgres

# Aliases for the cache
set system static-host-mapping host-name cache01.local alias redis
set system static-host-mapping host-name cache01.local alias cache
```

### IPv6 Support

```bash
# IPv4 entry
set system static-host-mapping host-name server.example.com inet 192.168.1.10

# IPv6 entry (if supported)
set system static-host-mapping host-name server.example.com inet6 2001:db8::10

# Dual-stack host
set system static-host-mapping host-name webserver.local inet 10.0.1.50
set system static-host-mapping host-name webserver.local inet6 fd00::50
set system static-host-mapping host-name webserver.local alias www
```

### Removing Entries

```bash
# Remove a specific alias
delete system static-host-mapping host-name server.local alias www

# Remove the entire host entry
delete system static-host-mapping host-name server.local

# Apply the changes
commit
save
```

## Cloud Platform Examples

### Example 1: Yandex Cloud - Cloud-init vs Static Configuration

In Yandex Cloud the host name can be set via cloud-init when a VM is created. However, to guarantee the name is preserved, it is recommended to use the VyOS configuration.

#### Scenario: Conflict Between cloud-init and VyOS config

```bash
# Situation: cloud-init sets the hostname "instance-1"
# Requirement: override it to "vyos-edge-router"

# Solution: the VyOS configuration takes precedence
configure
set system host-name vyos-edge-router
set system domain-name ru-central1.internal

# Static entries for internal Yandex Cloud services
set system static-host-mapping host-name metadata.yandex inet 169.254.169.254
set system static-host-mapping host-name metadata.yandex alias metadata

# Internal servers in Yandex Cloud
set system static-host-mapping host-name app-server-1.ru-central1.internal inet 10.128.0.10
set system static-host-mapping host-name app-server-2.ru-central1.internal inet 10.128.0.11
set system static-host-mapping host-name db-master.ru-central1.internal inet 10.129.0.5

commit
save
exit
```

#### Verifying Configuration Precedence

```bash
# Check the configured host name
vyos@vyos-edge-router:~$ show host name
vyos-edge-router

# Check the FQDN
vyos@vyos-edge-router:~$ hostname -f
vyos-edge-router.ru-central1.internal

# Check resolution of the metadata server
vyos@vyos-edge-router:~$ ping metadata
PING metadata.yandex (169.254.169.254) 56(84) bytes of data.
```

#### Post-deployment Script for Yandex Cloud

```bash
#!/bin/vbash
# vyos-yandex-cloud-init.sh
# Script for configuring VyOS in Yandex Cloud after deployment

source /opt/vyatta/etc/functions/script-template

configure

# Basic host configuration
set system host-name vyos-router-{{ zone_id }}
set system domain-name {{ folder_name }}.yandex.internal

# Yandex Cloud metadata service
set system static-host-mapping host-name metadata.yandex.cloud inet 169.254.169.254
set system static-host-mapping host-name metadata.yandex.cloud alias metadata
set system static-host-mapping host-name metadata.yandex.cloud alias cloud-init

# Yandex Cloud DNS servers
set system name-server 192.168.0.2

commit
save
exit
```

### Example 2: VK Cloud - DNS Resolution with Static Hosts

In VK Cloud you often need to configure local names for internal services when there is no corporate DNS.

#### Configuration for a VK Cloud Project

```bash
configure

# Base configuration
set system host-name vkcloud-gateway
set system domain-name msk1.cloud.vk.com

# Static entries for VK Cloud infrastructure endpoints
set system static-host-mapping host-name infra.mail.ru inet 10.0.0.1
set system static-host-mapping host-name infra.mail.ru alias vk-infra

# Internal project servers
set system static-host-mapping host-name app-frontend.msk1.cloud.vk.com inet 10.0.10.10
set system static-host-mapping host-name app-frontend.msk1.cloud.vk.com alias frontend
set system static-host-mapping host-name app-frontend.msk1.cloud.vk.com alias web

set system static-host-mapping host-name app-backend.msk1.cloud.vk.com inet 10.0.10.20
set system static-host-mapping host-name app-backend.msk1.cloud.vk.com alias backend
set system static-host-mapping host-name app-backend.msk1.cloud.vk.com alias api

set system static-host-mapping host-name db-postgres.msk1.cloud.vk.com inet 10.0.20.5
set system static-host-mapping host-name db-postgres.msk1.cloud.vk.com alias database
set system static-host-mapping host-name db-postgres.msk1.cloud.vk.com alias postgres
set system static-host-mapping host-name db-postgres.msk1.cloud.vk.com alias db

set system static-host-mapping host-name cache-redis.msk1.cloud.vk.com inet 10.0.20.15
set system static-host-mapping host-name cache-redis.msk1.cloud.vk.com alias redis
set system static-host-mapping host-name cache-redis.msk1.cloud.vk.com alias cache

# Monitoring and logging
set system static-host-mapping host-name monitoring.msk1.cloud.vk.com inet 10.0.30.10
set system static-host-mapping host-name monitoring.msk1.cloud.vk.com alias prometheus
set system static-host-mapping host-name monitoring.msk1.cloud.vk.com alias grafana

set system static-host-mapping host-name logging.msk1.cloud.vk.com inet 10.0.30.20
set system static-host-mapping host-name logging.msk1.cloud.vk.com alias syslog
set system static-host-mapping host-name logging.msk1.cloud.vk.com alias logs

commit
save
exit
```

#### Testing Resolution

```bash
# Check resolution by full name
vyos@vkcloud-gateway:~$ ping app-frontend.msk1.cloud.vk.com
PING app-frontend.msk1.cloud.vk.com (10.0.10.10) 56(84) bytes of data.

# Check resolution by alias
vyos@vkcloud-gateway:~$ ping frontend
PING app-frontend.msk1.cloud.vk.com (10.0.10.10) 56(84) bytes of data.

# Check resolution with automatic domain appending
vyos@vkcloud-gateway:~$ ping app-backend
PING app-backend.msk1.cloud.vk.com (10.0.10.20) 56(84) bytes of data.

# Check the contents of /etc/hosts
vyos@vkcloud-gateway:~$ cat /etc/hosts
```

### Example 3: Hybrid Configuration with External DNS

```bash
configure

# Base configuration
set system host-name border-router
set system domain-name production.internal

# DNS servers (external + local)
set system name-server 8.8.8.8
set system name-server 8.8.4.4
set system name-server 192.168.1.53

# Static entries for critical local services
# (used when DNS is unavailable)
set system static-host-mapping host-name dc1-core.production.internal inet 192.168.1.1
set system static-host-mapping host-name dc1-core.production.internal alias core-switch

set system static-host-mapping host-name dc1-fw.production.internal inet 192.168.1.254
set system static-host-mapping host-name dc1-fw.production.internal alias firewall

set system static-host-mapping host-name ntp-primary.production.internal inet 192.168.1.10
set system static-host-mapping host-name ntp-primary.production.internal alias ntp

set system static-host-mapping host-name dns-primary.production.internal inet 192.168.1.53
set system static-host-mapping host-name dns-primary.production.internal alias dns

commit
save
exit
```

## Verification and Monitoring Commands

### Checking the Current Configuration

```bash
# Show the configured host name
show host name

# Show host information (hostname + domain)
show host

# Show the FQDN
show host fqdn

# Show all static entries
show system static-host-mapping

# Show the system configuration
show configuration system
```

### Checking at the OS Level

```bash
# Current host name (short)
hostname

# FQDN
hostname -f

# All host names
hostname -A

# Domain name
hostname -d

# Contents of /etc/hosts
cat /etc/hosts

# Contents of /etc/hostname
cat /etc/hostname

# Resolution via getent
getent hosts server.local
```

### Testing DNS Resolution

```bash
# Ping by name
ping server.local

# DNS lookup with nslookup
nslookup server.local

# DNS lookup with dig
dig server.local

# DNS lookup with host
host server.local

# Trace the resolution
dig +trace server.local
```

### Example Command Output

#### show host

```bash
vyos@router01:~$ show host
Hostname: router01
Domain:   corp.example.com
FQDN:     router01.corp.example.com
```

#### show host name

```bash
vyos@router01:~$ show host name
router01
```

#### show system static-host-mapping

```bash
vyos@router01:~$ show system static-host-mapping
host-name           inet            alias
db-server.local     10.0.1.100      database, db, mysql
web01.local         10.0.10.11      www1
web02.local         10.0.10.12      www2
```

#### cat /etc/hosts (generated)

```bash
vyos@router01:~$ cat /etc/hosts
127.0.0.1       localhost
127.0.1.1       router01.corp.example.com router01

# Static host mappings
10.0.1.100      db-server.local database db mysql
10.0.10.11      web01.local www1
10.0.10.12      web02.local www2

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
```

## Troubleshooting

### Problem 1: Host Name Is Not Applied After commit

**Symptoms:**
- The `show host name` command shows the new name
- The CLI prompt has not changed
- The `hostname` command shows the old value

**Diagnostics:**

```bash
# Check the configuration
show configuration system host-name

# Check at the OS level
hostname
cat /etc/hostname
```

**Solution:**

```bash
# Re-save the configuration
configure
commit
save
exit

# Restart the SSH session (reconnect)
# or run
sudo systemctl restart vyos-router
```

### Problem 2: Static Entries Do Not Work

**Symptoms:**
- `ping server.local` does not work
- `cat /etc/hosts` does not contain the static entries

**Diagnostics:**

```bash
# Check the static entry configuration
show configuration system static-host-mapping

# Check /etc/hosts
cat /etc/hosts

# Check the resolution order
cat /etc/nsswitch.conf | grep hosts
```

**Solution:**

```bash
# Make sure the configuration is applied
configure
show system static-host-mapping
commit
save
exit

# Force regeneration of /etc/hosts
sudo /opt/vyatta/sbin/vyatta-update-hosts.pl

# Check the result
cat /etc/hosts
```

### Problem 3: FQDN Is Built Incorrectly

**Symptoms:**
- `hostname -f` returns an incorrect value
- The FQDN does not include the domain name

**Diagnostics:**

```bash
# Check hostname and domain separately
show host name
show configuration system domain-name

# Check at the OS level
hostname -s    # short name
hostname -f    # FQDN
hostname -d    # domain
```

**Solution:**

```bash
configure

# Verify and fix the configuration
set system host-name correct-hostname
set system domain-name correct.domain.com

commit
save
exit

# Check the result
hostname -f
```

### Problem 4: Cloud-init Overrides the hostname

**Symptoms:**
- After a reboot the hostname reverts to the value from cloud-init
- The VyOS configuration is ignored

**Diagnostics:**

```bash
# Check the cloud-init configuration
cat /etc/cloud/cloud.cfg | grep preserve_hostname

# Check the cloud-init logs
cat /var/log/cloud-init.log | grep hostname
```

**Solution:**

```bash
# Disable hostname management via cloud-init
sudo vi /etc/cloud/cloud.cfg

# Change:
# preserve_hostname: false
# to:
# preserve_hostname: true

# Or give the VyOS configuration precedence
configure
set system host-name my-vyos-router
commit
save
exit

# Reboot to verify
sudo reboot
```

### Problem 5: DNS Resolution Ignores static-host-mapping

**Symptoms:**
- `ping server.local` goes to DNS instead of the local /etc/hosts
- External DNS returns NXDOMAIN

**Diagnostics:**

```bash
# Check the resolution order
cat /etc/nsswitch.conf | grep hosts

# It should be:
# hosts: files dns
# NOT:
# hosts: dns files

# Check /etc/hosts
cat /etc/hosts | grep server.local
```

**Solution:**

```bash
# Make sure the entry exists in the configuration
configure
show system static-host-mapping
commit
save
exit

# If nsswitch.conf is incorrect, this is a VyOS bug
# Temporary workaround:
sudo vi /etc/nsswitch.conf
# Change the hosts line to: hosts: files dns

# Permanent fix - update VyOS or create a post-config script
```

## Best Practices

### 1. Naming Hosts

**Use descriptive, structured names:**

```bash
# Good: role-location-number
set system host-name vyos-gw-msk-01
set system host-name vyos-fw-spb-02
set system host-name vyos-edge-kzn-01

# Bad: unclear or too long
set system host-name router
set system host-name x
set system host-name my-super-duper-production-vyos-router-in-moscow
```

**Use a consistent scheme:**

```bash
# Scheme: service-type-zone-id
set system host-name web-frontend-dc1-01
set system host-name db-postgres-dc1-master
set system host-name cache-redis-dc2-01
```

### 2. Domain Names

**Use internal domains for private networks:**

```bash
# Good: .internal, .local, .private, .lan
set system domain-name corp.internal
set system domain-name datacenter.local
set system domain-name cloud.private

# Avoid: public domains for internal networks
# Bad:
set system domain-name example.com  # if not actually used
```

**Reflect the network structure in domains:**

```bash
# Hierarchical structure
set system domain-name moscow.datacenter.mycompany.internal
set system domain-name production.cloud.mycompany.ru
set system domain-name dmz.external.mycompany.net
```

### 3. Static Host Mappings

**Document the purpose of entries:**

```bash
configure

# Infrastructure services - critical services
set system static-host-mapping host-name ntp.internal inet 10.0.0.10
set system static-host-mapping host-name ntp.internal alias time

set system static-host-mapping host-name dns.internal inet 10.0.0.53
set system static-host-mapping host-name dns.internal alias resolver

# Application servers
set system static-host-mapping host-name app01.internal inet 10.0.10.11
set system static-host-mapping host-name app02.internal inet 10.0.10.12

commit
save
exit
```

**Use aliases for convenience:**

```bash
# Full name + short aliases
set system static-host-mapping host-name database-primary.internal inet 10.0.20.5
set system static-host-mapping host-name database-primary.internal alias db
set system static-host-mapping host-name database-primary.internal alias postgres
set system static-host-mapping host-name database-primary.internal alias primary
```

### 4. Redundancy for Critical Entries

**Duplicate DNS in static-host-mapping:**

```bash
# Critical services should resolve even when DNS is down
set system static-host-mapping host-name ntp-server.internal inet 192.168.1.10
set system static-host-mapping host-name dns-server.internal inet 192.168.1.53
set system static-host-mapping host-name mgmt-gateway.internal inet 192.168.1.1
set system static-host-mapping host-name syslog-server.internal inet 192.168.1.100
```

### 5. Integration with Cloud Providers

**Yandex Cloud:**

```bash
# Use zonal names
set system host-name vyos-gw-ru-central1-a
set system domain-name ru-central1.internal

# Add the metadata service
set system static-host-mapping host-name metadata.yandex inet 169.254.169.254
```

**VK Cloud:**

```bash
# Use the region in the naming
set system host-name vyos-router-msk1
set system domain-name msk1.cloud.internal

# Add Cloud infrastructure endpoints
set system static-host-mapping host-name infra.mail.ru inet 10.0.0.1
```

### 6. Configuration Versioning

**Use commit comments:**

```bash
configure
set system host-name new-router-name
commit comment "Changed hostname from old-router to new-router-name for standardization"
save
```

**Make backups before changes:**

```bash
# Save the current configuration
save /config/backup-before-hostname-change.config

# Make the changes
configure
set system host-name new-name
commit
save
```

### 7. Monitoring and Auditing

**Regularly check for consistency:**

```bash
# Hostname consistency check script
#!/bin/bash

VYOS_HOSTNAME=$(show host name)
OS_HOSTNAME=$(hostname)

if [ "$VYOS_HOSTNAME" != "$OS_HOSTNAME" ]; then
    echo "WARNING: Hostname mismatch!"
    echo "VyOS config: $VYOS_HOSTNAME"
    echo "OS hostname: $OS_HOSTNAME"
fi
```

**Log changes:**

```bash
# View the hostname change history
show system commit

# View a specific commit
show system commit diff <commit-number>
```

## Integration with Other VyOS Services

### SNMP

The hostname is used as SNMPv2-MIB::sysName:

```bash
configure
set system host-name core-router-01
set service snmp community public
commit
save
exit

# An SNMP query will show the hostname
snmpget -v2c -c public localhost SNMPv2-MIB::sysName.0
# Output: SNMPv2-MIB::sysName.0 = STRING: core-router-01
```

### Syslog

The hostname is included in syslog messages:

```bash
configure
set system host-name vyos-gateway
set system syslog global facility all level info
set system syslog host 10.0.0.100 facility all level warning
commit
save
exit

# Syslog messages will contain the hostname:
# Dec 15 10:30:45 vyos-gateway systemd[1]: Started VyOS Router.
```

### NTP

When configuring an NTP server, the hostname is used for identification:

```bash
configure
set system host-name ntp-client-router
set system ntp server 0.pool.ntp.org
set system ntp server 1.pool.ntp.org
commit
save
exit
```

### SSH Banner

The hostname can be used in the SSH banner:

```bash
configure
set system host-name secure-gateway
set system login banner pre-login "
****************************************************
  Authorized access only!
  Hostname: secure-gateway
  Location: Moscow Datacenter
****************************************************
"
commit
save
exit
```

## Complete Configuration Examples

### Configuration 1: Corporate Gateway

```bash
configure

# Hostname and domain
set system host-name corp-gateway-msk
set system domain-name moscow.corp.internal

# Internal servers
set system static-host-mapping host-name dc-controller.moscow.corp.internal inet 10.10.0.10
set system static-host-mapping host-name dc-controller.moscow.corp.internal alias dc
set system static-host-mapping host-name dc-controller.moscow.corp.internal alias ad

set system static-host-mapping host-name exchange.moscow.corp.internal inet 10.10.0.20
set system static-host-mapping host-name exchange.moscow.corp.internal alias mail

set system static-host-mapping host-name fileserver.moscow.corp.internal inet 10.10.0.30
set system static-host-mapping host-name fileserver.moscow.corp.internal alias fs
set system static-host-mapping host-name fileserver.moscow.corp.internal alias files

# Infrastructure
set system static-host-mapping host-name ntp.moscow.corp.internal inet 10.10.0.1
set system static-host-mapping host-name ntp.moscow.core.internal alias time

set system static-host-mapping host-name dns.moscow.corp.internal inet 10.10.0.2
set system static-host-mapping host-name dns.moscow.corp.internal alias resolver

# Monitoring
set system static-host-mapping host-name zabbix.moscow.corp.internal inet 10.10.0.100
set system static-host-mapping host-name zabbix.moscow.corp.internal alias monitoring

commit
save
exit
```

### Configuration 2: Cloud Edge Router (Yandex Cloud)

```bash
configure

# Cloud hostname
set system host-name yc-edge-router-01
set system domain-name ru-central1-a.cloud.internal

# Yandex Cloud metadata
set system static-host-mapping host-name metadata.yandex.cloud inet 169.254.169.254
set system static-host-mapping host-name metadata.yandex.cloud alias metadata
set system static-host-mapping host-name metadata.yandex.cloud alias cloud-init

# Application infrastructure in Yandex Cloud
set system static-host-mapping host-name app-lb.ru-central1-a.cloud.internal inet 10.128.0.10
set system static-host-mapping host-name app-lb.ru-central1-a.cloud.internal alias loadbalancer
set system static-host-mapping host-name app-lb.ru-central1-a.cloud.internal alias lb

set system static-host-mapping host-name app-web-01.ru-central1-a.cloud.internal inet 10.128.0.20
set system static-host-mapping host-name app-web-01.ru-central1-a.cloud.internal alias web1

set system static-host-mapping host-name app-web-02.ru-central1-a.cloud.internal inet 10.128.0.21
set system static-host-mapping host-name app-web-02.ru-central1-a.cloud.internal alias web2

set system static-host-mapping host-name db-managed-postgres.ru-central1-a.cloud.internal inet 10.129.0.5
set system static-host-mapping host-name db-managed-postgres.ru-central1-a.cloud.internal alias database
set system static-host-mapping host-name db-managed-postgres.ru-central1-a.cloud.internal alias postgres

# Yandex Cloud DNS (internal)
set system name-server 192.168.0.2

commit
save
exit
```

### Configuration 3: VK Cloud Multi-zone Setup

```bash
configure

# VK Cloud hostname
set system host-name vkc-router-msk1-zone-a
set system domain-name msk1.vkcloud.internal

# VK Cloud infrastructure
set system static-host-mapping host-name infra.mail.ru inet 10.0.0.1
set system static-host-mapping host-name infra.mail.ru alias vk-infra

# Zone A servers
set system static-host-mapping host-name web-a1.msk1.vkcloud.internal inet 10.0.10.11
set system static-host-mapping host-name web-a2.msk1.vkcloud.internal inet 10.0.10.12

# Zone B servers (cross-zone communication)
set system static-host-mapping host-name web-b1.msk1.vkcloud.internal inet 10.1.10.11
set system static-host-mapping host-name web-b2.msk1.vkcloud.internal inet 10.1.10.12

# Managed services
set system static-host-mapping host-name db-managed.msk1.vkcloud.internal inet 10.0.20.5
set system static-host-mapping host-name db-managed.msk1.vkcloud.internal alias database

set system static-host-mapping host-name cache-managed.msk1.vkcloud.internal inet 10.0.20.15
set system static-host-mapping host-name cache-managed.msk1.vkcloud.internal alias redis

# Monitoring and Logging
set system static-host-mapping host-name mon.msk1.vkcloud.internal inet 10.0.30.10
set system static-host-mapping host-name mon.msk1.vkcloud.internal alias monitoring
set system static-host-mapping host-name mon.msk1.vkcloud.internal alias prometheus

set system static-host-mapping host-name log.msk1.vkcloud.internal inet 10.0.30.20
set system static-host-mapping host-name log.msk1.vkcloud.internal alias syslog

commit
save
exit
```

## Automation and Scripts

### Bulk Host Addition Script

```bash
#!/bin/vbash
# add-static-hosts.sh
# Bulk addition of static entries from a CSV file

source /opt/vyatta/etc/functions/script-template

# CSV format: hostname,ip,alias1,alias2,alias3
# Example: web01.local,10.0.10.11,www1,web1,frontend1

HOSTS_FILE="/config/static-hosts.csv"

configure

while IFS=',' read -r hostname ip alias1 alias2 alias3; do
    # Skip comments and empty lines
    [[ "$hostname" =~ ^#.*$ ]] && continue
    [[ -z "$hostname" ]] && continue

    echo "Adding host: $hostname -> $ip"
    set system static-host-mapping host-name "$hostname" inet "$ip"

    if [ -n "$alias1" ]; then
        set system static-host-mapping host-name "$hostname" alias "$alias1"
    fi

    if [ -n "$alias2" ]; then
        set system static-host-mapping host-name "$hostname" alias "$alias2"
    fi

    if [ -n "$alias3" ]; then
        set system static-host-mapping host-name "$hostname" alias "$alias3"
    fi
done < "$HOSTS_FILE"

commit
save
exit

echo "Static hosts configuration completed!"
```

### Consistency Check Script

```bash
#!/bin/bash
# check-hostname-consistency.sh
# Check that the hostname matches between the VyOS config and the OS

VYOS_HOSTNAME=$(/opt/vyatta/bin/vyatta-op-cmd-wrapper show host name)
OS_HOSTNAME=$(hostname)
OS_FQDN=$(hostname -f)

echo "=== Hostname Consistency Check ==="
echo "VyOS Config Hostname: $VYOS_HOSTNAME"
echo "OS Hostname:          $OS_HOSTNAME"
echo "OS FQDN:              $OS_FQDN"
echo ""

if [ "$VYOS_HOSTNAME" = "$OS_HOSTNAME" ]; then
    echo "Status: OK - Hostnames match"
    exit 0
else
    echo "Status: WARNING - Hostname mismatch detected!"
    echo "Action required: Restart VyOS router or reconnect SSH session"
    exit 1
fi
```

### Hostname Configuration Export Script

```bash
#!/bin/vbash
# export-hostname-config.sh
# Export the hostname configuration in JSON format

source /opt/vyatta/etc/functions/script-template

OUTPUT_FILE="/config/hostname-export.json"

HOSTNAME=$(cli-shell-api showCfg system host-name)
DOMAIN=$(cli-shell-api showCfg system domain-name)

echo "{" > "$OUTPUT_FILE"
echo "  \"hostname\": \"$HOSTNAME\"," >> "$OUTPUT_FILE"
echo "  \"domain\": \"$DOMAIN\"," >> "$OUTPUT_FILE"
echo "  \"fqdn\": \"$HOSTNAME.$DOMAIN\"," >> "$OUTPUT_FILE"
echo "  \"static_hosts\": [" >> "$OUTPUT_FILE"

# Get the list of static host mappings
# (requires parsing the output of show configuration)

echo "  ]" >> "$OUTPUT_FILE"
echo "}" >> "$OUTPUT_FILE"

echo "Hostname configuration exported to $OUTPUT_FILE"
```

## Related Documents

- [System Configuration](/docs/vyos/system/) - General system configuration
- [Name Server (DNS)](/docs/vyos/system/vyos-name-server/) - Configuring DNS servers
- [NTP](/docs/vyos/services/vyos-ntp/) - Time and NTP configuration
- [Syslog](/docs/vyos/system/vyos-syslog/) - Configuring system logging
- [SNMP](/docs/vyos/services/vyos-snmp/) - Monitoring via SNMP
- [Cloud-init](/docs/vyos/admin-guide/vyos-automation/) - Automation in the cloud

## Additional Resources

- [RFC 1123 - Requirements for Internet Hosts](https://tools.ietf.org/html/rfc1123)
- [RFC 952 - DoD Internet Host Table Specification](https://tools.ietf.org/html/rfc952)
- [VyOS Documentation - System Host Name](https://docs.vyos.io/en/latest/configuration/system/host-name.html)
- [Yandex Cloud Metadata Service](https://cloud.yandex.ru/docs/compute/operations/vm-info/get-info)
- [VK Cloud Documentation](https://mcs.mail.ru/docs/)

## Conclusion

Properly configuring the host name, domain name, and static host mappings is a fundamental part of VyOS configuration. These parameters affect:

- Device identification on the network
- The operation of system services (syslog, SNMP, NTP)
- Integration with cloud platforms
- Manageability and monitoring of the infrastructure

Follow the recommendations in the "Best Practices" section to ensure a consistent and reliable configuration.