How to Set a Static IP Address on a Synology NAS

A Synology NAS depends on a reliable network connection for file sharing, backups, surveillance, virtualization, Synology Drive, and other business services. By default, many networks use DHCP to automatically assign an IP address to the NAS. While convenient, the assigned address can potentially change and cause problems for services configured to use a specific IP.

Setting a static IP address on a Synology NAS gives the device a consistent network address. This makes it easier to map shared folders, configure backup jobs, manage firewall rules, connect applications, and troubleshoot network problems.

However, static addressing must be configured correctly. An incorrect IP address, subnet mask, gateway, or DNS configuration can make the NAS inaccessible.

What Is a Static IP Address?

An IP address identifies the Synology NAS on the network.

A typical private IPv4 address might look like:

192.168.1.50

With DHCP, the router or another DHCP server assigns an address automatically. With a static configuration, the NAS uses network settings specified by the administrator.

The objective is simple: keep the NAS at a predictable address so other systems always know where to find it.

Why Give a Synology NAS a Static IP?

Consistent addressing is useful when the NAS provides services used by multiple devices.

Common examples include:

• Mapped network drives
• Backup destinations
• Synology Drive
• Virtual machines
• Surveillance systems
• Directory services
• Internal applications
• Firewall rules
• Remote management through secure networks

If these services depend on an IP address that changes unexpectedly, users or applications may temporarily lose connectivity.

Static IP vs. DHCP Reservation

Before manually configuring DSM, consider whether a DHCP reservation would be more appropriate.

A static IP is configured directly on the Synology NAS.

A DHCP reservation is configured on the router or DHCP server and instructs it to provide the same address to a particular NAS network interface.

Both can provide consistent addressing.

DHCP reservations are often easier to manage in small environments because addressing remains centralized. Businesses with structured server networks may prefer manually assigned static addresses.

Step 1: Check Your Current Network Configuration

Before changing anything, record the NAS’s existing network information.

You need to understand:

• Current IP address
• Subnet mask
• Default gateway
• DNS server
• Network interface
• DHCP range

For example, the current configuration might be:

IP Address: 192.168.1.25
Subnet Mask: 255.255.255.0
Gateway: 192.168.1.1
DNS: 192.168.1.1

Do not copy these example values unless they match your actual network.

Step 2: Choose an Appropriate IP Address

Select an address that belongs to the correct subnet but does not conflict with another device.

For example, if your network uses:

192.168.1.x

you might choose:

192.168.1.50

However, you first need to confirm that .50 is available and appropriate for your network.

IP conflicts occur when two devices attempt to use the same address. This can cause intermittent connectivity or make one or both devices inaccessible.

Step 3: Check the DHCP Range

Your router may automatically distribute addresses from a defined DHCP pool.

For example:

192.168.1.100 to 192.168.1.200

In a properly planned network, administrators may reserve addresses outside that dynamic pool for infrastructure devices.

The important point is to coordinate static addressing with the DHCP configuration.

Never assume an address is available simply because no device appears to be using it at that moment.

Step 4: Open DSM Network Settings

Sign in to Synology DSM using an administrator account.

Navigate to the network settings in Control Panel and locate the active network interface.

Depending on your NAS, you may see interfaces such as:

• LAN 1
• LAN 2
• Bonded interfaces
• VLAN interfaces

Make sure you modify the interface that currently provides network connectivity.

Changing the wrong interface may not accomplish the intended configuration.

Step 5: Configure the Manual Network Settings

Open the IPv4 configuration for the appropriate network interface and change it from automatic DHCP addressing to manual configuration.

Enter the required information, including:

• IP address
• Subnet mask
• Default gateway
• DNS server where applicable

Carefully verify every value before applying the change.

Once the new configuration takes effect, the NAS will stop responding at its previous address and should become available at the new static address.

Step 6: Reconnect to DSM

After the IP address changes, your existing browser session may disconnect.

This is expected.

Open a new browser connection using the newly assigned NAS address.

If DSM appears and you can sign in successfully, the new network configuration is working.

You should also test access from another authorized workstation if the NAS serves multiple users.

Step 7: Test Shared Folders

Changing the NAS IP can affect resources that reference the old address directly.

Test important services such as:

• SMB shared folders
• Mapped drives
• Backup applications
• Synology Drive
• Internal applications
• Surveillance integrations

For example, a Windows share configured using the old IP may need to be updated to reference the new address.

Using DNS hostnames instead of hard-coded IP addresses can simplify some environments.

Configure DNS Correctly

DNS is easy to overlook during static IP configuration.

If the NAS cannot resolve domain names, services requiring external connectivity may experience problems even though local file access still works.

Verify that the NAS has access to appropriate DNS servers.

Businesses using Active Directory or internal DNS infrastructure should follow their existing network architecture rather than automatically entering a public DNS service.

Configure the Default Gateway

The default gateway provides a path from the NAS to networks outside its local subnet.

In many small environments, the gateway is the router.

An incorrect gateway can prevent the NAS from reaching:

• Internet services
• Remote networks
• Cloud backup destinations
• Software update services
• Other routed subnets

Local connectivity may continue working, which can make a gateway problem less obvious.

What If You Lose Access to the NAS?

If DSM becomes inaccessible after changing the network configuration, do not immediately assume the NAS has failed.

First check:

• New IP address
• Subnet mask
• Gateway
• Ethernet connection
• Computer subnet
• VLAN
• Firewall rules

Synology Assistant or other appropriate network discovery methods may help locate the NAS if its address is uncertain.

Avoid making unnecessary storage or RAID changes when troubleshooting a network configuration problem.

Multiple LAN Ports Require Extra Planning

Business Synology systems may have multiple network interfaces.

Organizations might use them for:

• Link aggregation
• Network redundancy
• Separate backup traffic
• VLANs
• Storage networks
• Management networks

Assigning static addresses across several interfaces requires careful planning to prevent routing conflicts and unexpected traffic behaviour.

Document the purpose of each interface before changing its configuration.

Document the Static IP

Once everything works, update your infrastructure documentation.

Record information such as:

• NAS hostname
• Static IP
• Subnet
• Gateway
• DNS servers
• MAC address
• Network interface
• VLAN
• Purpose of the connection

Good documentation can save considerable troubleshooting time when routers, switches, firewalls, or NAS systems are replaced later.

When Professional Synology Support Helps

A basic static IP configuration is straightforward on a small network. Business environments involving VLANs, multiple LAN interfaces, VPNs, Active Directory, link aggregation, firewalls, or multiple locations require more careful planning.

Incorrect network configuration can interrupt file access, backups, replication, and other critical services.

Professional Synology support can help organizations configure addressing as part of a broader, reliable network architecture.

About Epis Technology

Epis Technology helps organizations configure, troubleshoot, secure, and optimize Synology NAS environments. Services include Synology NAS setup, static IP configuration, VLAN and network planning, high-speed networking, secure remote access, storage architecture, backup implementation, disaster recovery, and cybersecurity assessments. Epis Technology’s Synology expertise helps businesses maintain reliable access to critical storage while building secure, scalable network infrastructure for long-term operations.