How to Set Up Link Aggregation (LACP) Between Your NAS and Router: Doubling NAS Throughput with 802.3ad on Synology, QNAP, and Home Switches

If your NAS has two or more Ethernet ports and your managed switch supports 802.3ad, you can bond those links together using Link Aggregation Control Protocol (LACP) — effectively giving your NAS a wider pipe to the rest of your network. The setup is straightforward on both Synology DSM and QNAP QTS, but there’s a frequently misunderstood limitation you need to understand before you start: link aggregation does not increase the speed for any single client. A bonded pair of 1 Gbps ports gives your NAS 2 Gbps of aggregate capacity, but any one device reading from that NAS is still capped at 1 Gbps. The real benefit is that multiple simultaneous clients each get their own full-speed lane rather than sharing a single 1 Gbps pipe. With that understanding in place, here is how to set it up correctly.

What Link Aggregation Actually Does (and Doesn’t Do)

Link aggregation — also called port trunking, NIC bonding, or IEEE 802.3ad — combines two physical Ethernet interfaces between two devices into one logical channel. The switch and NAS negotiate which port carries which traffic flows using a hashing algorithm (typically based on source and destination MAC or IP addresses). The result is that different conversations use different physical links simultaneously.

The practical implication: if you have three computers each transferring files from the NAS at the same time, the switch distributes those sessions across two 1 Gbps links, and the NAS can sustain close to 2 Gbps of total output. If only one computer is reading from the NAS, that single session still maxes out at roughly 1 Gbps. Link aggregation is a multi-client throughput multiplier, not a single-client speed booster. For a single heavy-transfer workstation, upgrading to a 2.5 Gbps or 10 Gbps NIC is a more direct solution — see our gigabit Ethernet comparison guide for more context.

What You Need Before You Start

• A NAS with two or more LAN ports. Entry-level single-port NAS units cannot be bonded — you need a model like the Synology DS923+, DS1522+, or QNAP TS-453E that ships with dual or quad Ethernet.
• A managed switch that supports IEEE 802.3ad LACP. This is the critical hardware requirement. Unmanaged switches cannot participate in LACP. Budget “smart” switches vary: the TP-Link TL-SG108E supports static LAG but not true 802.3ad LACP, while the NETGEAR GS308E supports neither. For proper dynamic LACP, you need a fully managed switch such as the TP-Link TL-SG2008, NETGEAR GS310TP, or any Ubiquiti UniFi switch.
• Two Ethernet cables running from the NAS to the same switch (not two different switches).
• Matching port speeds. All ports in the LAG must run at the same speed and duplex. Do not mix a 1 Gbps port with a 2.5 Gbps port in the same bond.

Setting Up LACP on the Switch First

Always configure the switch before the NAS. If the NAS tries to negotiate LACP against ports that haven’t been configured yet, it may fall back to a degraded state or become unreachable. Configure the switch LAG first, then add the NAS bond.

TP-Link Smart Managed Switches (TL-SG2008 and Similar)

1. Log into the switch management page (default IP is usually 192.168.0.1).
2. Navigate to L2 Features → LAG → LAG Settings.
3. Click Add, select the two ports connected to your NAS (e.g., ports 7 and 8), and set the type to LACP.
4. Click Apply. The ports will now negotiate 802.3ad with whatever device is connected.

NETGEAR Managed Switches (GS310TP and Similar)

1. Open the switch web UI and go to Switching → Link Aggregation → LAG Configuration.
2. Select a LAG group (e.g., LAG 1), set the mode to LACP, and check the two ports connected to your NAS.
3. Click Apply.

Configuring Link Aggregation on Synology DSM

Synology DSM refers to link aggregation as a “bond.” The setup lives in the network control panel and takes about two minutes.

1. Open Control Panel → Network → Network Interface.
2. Click Create → Create Bond.
3. Select IEEE 802.3ad Dynamic Link Aggregation from the mode dropdown. (Choose “Adaptive Load Balancing” only if your switch does not support LACP — it works without switch cooperation but is less efficient.)
4. Check both physical Ethernet interfaces (LAN 1 and LAN 2) that are cabled to your switch LAG group.
5. Click Next, assign an IP address (static is recommended for a NAS), set the gateway, and click Apply.

DSM will briefly drop off the network while it brings the bond up. Within 30–60 seconds the NAS should reappear on the network at the same IP address. Verify by opening a browser and navigating to the NAS IP — if DSM loads, the bond is live. You can confirm LACP negotiation is working by checking Control Panel → Network → Network Interface and looking for a bond status of “Connected” with both member ports showing as active.

Configuring Link Aggregation on QNAP QTS

QNAP calls this feature “Port Trunking” and manages it through the Network & Virtual Switch app.

1. Open Main Menu → Network & Virtual Switch.
2. In the left panel, select Interfaces, then click Port Trunking / Bonding.
3. Click the + button to create a new bond.
4. Select IEEE 802.3ad LACP as the bonding mode and check the two LAN interfaces to include.
5. Click Apply. QTS will renegotiate the link and both interfaces will appear under a single bonding interface with a combined status.

As with Synology, assign a static IP to the bonding interface so that file-sharing services (SMB, NFS, iSCSI) always resolve to the same address.

Verifying the Bond Is Working

After setup, run simultaneous file transfers from two different computers to the NAS and watch the network activity in DSM’s Resource Monitor or QNAP’s Network & Virtual Switch throughput graph. You should see both physical links carrying traffic. If only one link shows activity, the switch LAG is likely misconfigured — double-check that both ports on the switch are assigned to the same LAG group and that the mode is LACP (not static/manual).

To measure aggregate throughput, use a tool like iperf3: launch an iperf3 server on the NAS and run two simultaneous iperf3 client sessions from different machines. With a correctly configured LACP bond, the combined throughput across both sessions should approach 2 Gbps on a gigabit network. For a deeper look at how wired versus wireless connections compare in practice, see our gigabit Ethernet vs WiFi guide. If your home network uses MoCA for backhaul rather than direct Ethernet runs, our MoCA adapters guide explains how coax-based Ethernet affects available bandwidth for NAS traffic.

Common Pitfalls

• Configuring the NAS before the switch. Always enable the LAG on the switch first. A NAS sending LACP packets to unconfigured switch ports may lock itself into a degraded state that requires a physical console connection to fix.
• Using a switch that only supports static LAG. Static LAG requires both ends to be manually configured and will not automatically recover if one link fails in the same way that LACP does. If your switch only offers static LAG, it still works — just expect less graceful failover.
• Expecting single-client speedup. A single Robocopy or rsync job to the NAS will not exceed 1 Gbps on a bonded gigabit link. If that is your bottleneck, upgrade the NIC and switch port to 2.5 Gbps or 10 Gbps instead.
• Mismatched port speeds in the bond. All member ports must negotiate at the same speed. Mixing a 1 Gbps and 2.5 Gbps port in one LAG will cause the bond to fail or fall back to the slower speed.