---
title: "Do I have to open the port on my router by hand? Does a closed port slow me down?"
url: "https://forum.qnap.net.pl/threads/do-i-have-to-open-the-port-on-my-router-by-hand-does-a-closed-port-slow-me-down.46307/"
thread_id: 46307
date: "2026-11-11"
category: "FAQ"
section: "Knowledge base"
source: "Forum QNAP Polska"
site: "https://forum.qnap.net.pl"
language: "pl"
ai_policy: "https://forum.qnap.net.pl/ai-policy.md"
license: "https://forum.qnap.net.pl/ai-policy.md"
---

# Do I have to open the port on my router by hand? Does a closed port slow me down?

> Source: <https://forum.qnap.net.pl/threads/do-i-have-to-open-the-port-on-my-router-by-hand-does-a-closed-port-slow-me-down.46307/> · FAQ · Forum QNAP Polska · 2026-11-11

**Symptoms**

- **Network & NAT** shows **IPv4 TCP port … not reachable**.
- You are not sure whether you have to forward the port on your router yourself.

**Cause**
Peers connect to rtorrent through one BitTorrent port over TCP and UDP, and to DHT through one UDP port. If the port is closed, rtorrent still connects to peers itself, but fewer peers can connect to you. A closed port prevents connections to peers that cannot accept incoming connections themselves. By default, Rtorrent 16 asks the router over UPnP and PCP / NAT-PMP to map the BitTorrent port (TCP and UDP) and the DHT port (UDP). It makes these requests at every start and after you save a port setting. If the router accepts them, you do not have to forward anything by hand.

**Resolution**

1. Check the port. Open **Network & NAT** and press **Check TCP port**. If the **BitTorrent port** card reads **IPv4 TCP port … open**, you do not need to do anything.
![](https://forum.qnap.net.pl/attachments/75935/)
2. Check what the router mapped. In the **Network services** card on the same page, **Mapped as** shows what the router granted, and **By** shows which method was used. **Not mapped** means that the router mapped nothing for that port.
3. Check the switches. In **Settings → Port forwarding & VPN**, under **Router port mappings**, **UPnP** and **PCP / NAT-PMP** should both be on. UPnP or PCP / NAT-PMP must also be on in the router itself. While a port is not mapped, Rtorrent 16 asks the router again every five minutes.
![](https://forum.qnap.net.pl/attachments/75936/)
4. If the router does not map the ports, forward them manually: the BitTorrent port over TCP and UDP, and the DHT port over UDP, to the NAS's LAN address. The numbers are in the **Port** column of **Network services**. Then press **Check TCP port** again.

**Notice & Advise**

- A port forwarded manually works while the switches are on, but it does not appear under **Mapped as**.
- If **Route to the internet** shows **Possible multiple routers** or **Another NAT likely before your router (IPv4)**, a forward on your own router alone may not open the port. The card lists what to do.

Ref. links:
[Rtorrent 16 guide: Ports](https://pub.qnaputilities.com/rtorrent16/demo/guides/?g=ports)

---

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