What Link Aggregation Means for a Synology NAS

Link aggregation combines two or more network connections between a Synology NAS and a compatible switch. The result can be better overall throughput for several users, along with failover if one network cable or port stops working. It is often called bonding, teaming, LAG, or LACP.

For a home office or small business in Australia, this can be useful when several computers access shared files at the same time. A NAS serving staff in Melbourne, a studio in Sydney, or a busy household using NBN cloud backups may benefit, although the improvement depends on the whole network rather than the NAS alone.

How Link Aggregation Works

A bonded interface presents multiple physical Ethernet ports as one logical connection. Traffic is distributed across those ports according to a balancing rule, while the network switch keeps track of the link group.

The most common standard is IEEE 802.3ad, usually shown as LACP or dynamic link aggregation. It can provide resilience and distribute traffic between multiple clients. It does not normally turn a single file copy into a guaranteed 2Gbps transfer over two 1Gbps ports, because one session may remain assigned to one physical link.

Hardware Requirements

The Synology NAS needs at least two suitable Ethernet ports. Many models, including selected Plus-series devices, provide multiple 1GbE connections, while some newer systems can use optional 10GbE hardware. Check the exact specification before buying; a useful comparison is this DS923+ and DS1522+ guide.

The switch must support link aggregation, and both NAS cables should connect to that same switch or to a properly configured stack. An unmanaged switch generally cannot create an LACP group. Cat5e is usually adequate for 1GbE, while higher-speed connections may require better cabling and compatible transceivers.

Select the Right Bonding Mode

LACP is usually the best choice when the switch supports it. It negotiates the group dynamically and can continue operating if one member link fails. The switch and NAS must agree on the configuration, and the two ports should be assigned to the same aggregation group.

Synology also offers modes such as adaptive load balancing or active-backup, depending on the DSM version and network hardware. Active-backup is simpler because it can work without switch aggregation, but it focuses on failover rather than combined capacity. Avoid static aggregation unless the switch documentation specifically calls for it.

Configure DSM on the NAS

Sign in to DSM, open Control Panel, select Network, and locate Network Interface. Choose Create, then Create Bond or Link Aggregation. Select the physical LAN ports, choose the appropriate mode, and apply the settings.

DSM may briefly disconnect while the new logical interface starts. Give the bond a clear name, confirm the IP address and gateway, and check that services such as SMB file sharing, Hyper Backup, and Synology Drive still use the bonded interface. If the NAS becomes unreachable, connect directly or use another management path to undo the change.

Configure the Managed Switch

Open the switch management interface and create an LAG containing the exact ports connected to the NAS. With LACP, set those ports to active or use the vendor’s equivalent dynamic mode. Keep VLAN membership, speed, duplex, and trunk settings consistent across the group.

Do not mix ports from unrelated switches unless the equipment supports stacking or multi-chassis aggregation. A common mistake is configuring LACP on the NAS but leaving the switch ports independent. That can cause intermittent access, packet loss, or a complete loss of connectivity.

Test Performance and Failover

After configuration, copy large files from several computers at once and monitor the NAS resource graphs and switch port statistics. Testing from one laptop alone may show little improvement, because link aggregation is most valuable when multiple clients generate traffic concurrently.

Unplug one Ethernet cable briefly to test resilience, then reconnect it and confirm that the bond returns to its normal state. Test from wired devices rather than relying on Wi-Fi, especially in Australian homes where wireless performance can vary between rooms and across busy apartment networks.

Understand the Practical Limits

Link aggregation does not increase the speed of an NBN service, and it cannot overcome a slow hard drive, a congested Wi-Fi network, or an internet provider’s upload limit. It is primarily a local network feature. In many Australian suburbs, NBN upload speeds remain far below the capacity of a dual-1GbE NAS connection, so local backups may benefit more than remote access.

Security still matters after bonding is enabled. Keep DSM patched, use strong accounts, enable two-factor authentication, and avoid exposing SMB directly to the internet. Treat unexpected links and unrelated pages, including astrology readings, separately from NAS administration and verify the address before entering credentials.

For most small networks, a reliable switch, sensible backups, and wired connections should come before aggregation. Link aggregation is most worthwhile when several users regularly access large media files, virtual machines, design projects, or shared business data at the same time.

The key point is that link aggregation joins multiple Ethernet paths for better shared capacity and resilience, but it requires compatible NAS ports, a managed switch, matching configuration, and realistic expectations about single-user speed.