Question Limit Bandwidth

[Thomas Oryon]

Hello Support,

While we create a service plan, we setup bandwidth as unlimited so the bandwidth for that server plan domains uses unlimited bandwidth. Here, is that possible to restrict the bandwidth in bankend of the both linux & plesk server but in front end it should show unlimited?

Awaiting your reply.

 

[TalkBuildHost]

Yes, it is technically possible, but it depends on how your hosting platform and billing/provisioning system are integrated.


If I understand correctly:

• Frontend/client-facing plan: Shows Unlimited Bandwidth.
• Backend/server side: You want to enforce an actual bandwidth limit on the account/domain.

Linux Server​

On a Linux server, bandwidth can be limited using various methods such as:

• Web server configuration (Apache, Nginx modules)
• Traffic shaping tools (tc, iptables, etc.)
• Hosting control panels
• Account-level quotas in some hosting environments

So from the operating system perspective, bandwidth restrictions can be applied regardless of what is displayed in the sales plan.

Plesk Server​

In Plesk, subscriptions can have resource limits configured. Depending on the Plesk version and service plan settings, you can:

• Set traffic/bandwidth limits for subscriptions.
• Limit monthly traffic usage.
• Suspend or notify users when limits are reached.

A common approach is:

1. Create a service plan that customers see as "Unlimited Bandwidth."
2. Provision the account with a hidden internal limit (for example, 5 TB/month).
3. Monitor usage and apply policies if the threshold is exceeded.

Important Considerations​

There are a few things to watch for:

• If customers can view resource limits in Plesk, they may see the actual limit instead of "Unlimited."
• Some billing systems (such as WHMCS, HostBill, or custom provisioning systems) synchronize plan limits with Plesk. In that case, the backend limit may become visible unless customized.
• Marketing a plan as "Unlimited" while enforcing a strict undisclosed limit may have legal or consumer-protection implications depending on your jurisdiction and terms of service. Many providers instead use a "fair usage policy."

Recommended Approach​

Rather than a hard hidden limit, many hosting companies:

• Display Unlimited Bandwidth.
• Implement a reasonable backend threshold (e.g., fair-use limit).
• Document the fair-use policy in the Terms of Service.
• Contact customers only if usage becomes excessive.

If you tell me:

• Which billing/provisioning system you use (WHMCS, HostBill, custom panel, etc.)
• Plesk version
• Whether this is VPS hosting, shared hosting, or reseller hosting

I can explain the exact configuration steps and I will here it is below:

To give exact steps, I need to know your environment because the configuration is different depending on how accounts are created.


Please provide:

1. Plesk version (e.g., Plesk Obsidian 18.x)
2. Operating system (Ubuntu 22.04, AlmaLinux 9, Rocky Linux 9, etc.)
3. Whether you're using:
   • WHMCS
   • HostBill
   • Another billing system
   • No billing system (manual account creation)
4. What you mean by bandwidth:
   • Monthly traffic quota (e.g., 1 TB/month)
   • Port speed limit (e.g., 100 Mbps)
   • Both

The exact configuration differs significantly:

• Plesk-only: Set subscription traffic limits in Service Plans.
• WHMCS + Plesk: Configure one value in WHMCS and another in Plesk using custom provisioning logic.
• Linux OS level: Use traffic shaping (tc) or firewall rules.
• Cloud/VPS providers: Sometimes bandwidth limits are enforced by the provider rather than Plesk.

 

[TalkBuildHost]

I see it:
If you're asking whether you can show "Unlimited Bandwidth" to customers while enforcing a limit behind the scenes, here's how it works in each case:

1. Plesk-Only​

Not really hidden.

Set a traffic limit​

1. Log in to Plesk as Administrator.
2. Go to Service Plans.
3. Select your hosting plan.
4. Open Resources.
5. Find Traffic (MB).
6. Enter the desired limit (for example, 1048576 MB = 1 TB).
7. Click Update & Sync.

Problem​

If the customer has access to subscription resources, Plesk can display the actual traffic limit. Therefore, you cannot truly have "Unlimited" in the client-facing Plesk interface while enforcing a lower Plesk traffic quota without customization.

---

2. WHMCS + Plesk​

This is the most common approach.

WHMCS Product​

1. In WHMCS, go to:
   • Configuration → System Settings → Products/Services
2. Edit the hosting package.
3. Set Bandwidth = 0 (WHMCS interprets this as Unlimited).
4. Customer-facing order forms will show Unlimited.

Plesk Service Plan​

1. Create a service plan in Plesk.
2. Set:
   • Traffic = desired internal limit.
3. Assign this service plan to accounts created via WHMCS.

Alternative​

Keep Plesk traffic unlimited and use monitoring scripts to:

• Alert at 1 TB
• Suspend at 1.5 TB
• Throttle at 2 TB

This allows WHMCS and Plesk to continue showing Unlimited.

---

3. Linux OS-Level Enforcement​

This is the best method if you want customers to see Unlimited but still protect server resources.

Install vnStat for monitoring​

Ubuntu/Debian:

Bash

apt update
apt install vnstat -y
systemctl enable vnstat
systemctl start vnstat

AlmaLinux/Rocky:

Bash
dnf install vnstat -y
systemctl enable vnstat
systemctl start vnstat

Check usage​

Bash
vnstat -m

Automatic suspension script​

Example:

bash
#!/bin/bash

LIMIT=1000

USED=$(vnstat --json | jq '.interfaces[0].traffic.month[0].rx + .interfaces[0].traffic.month[0].tx')

if [ "$USED" -gt "$LIMIT" ]; then
plesk bin subscription --disable example.com
fi

Run via cron.

Traffic shaping with tc​

Limit speed to 100 Mbps:

Bash
tc qdisc add dev eth0 root tbf rate 100mbit burst 32kbit latency 400ms

View:

Bash
tc qdisc show dev eth0

Remove:

Bash
tc qdisc del dev eth0 root

This controls throughput, not monthly transfer.

---

4. Cloud/VPS Provider Level​

Many providers allow bandwidth control outside Plesk.


Examples:

• DigitalOcean
• Vultr
• Linode
• Amazon Web Services

Possible controls:

• Monthly transfer quotas
• Network speed caps
• Billing alerts
• Automatic shutdown rules

In this scenario:

• WHMCS = Unlimited
• Plesk = Unlimited
• Provider enforces the real limit

Customers never see the actual restriction in the hosting panel.

Recommended Setup​

For most hosting companies:

• WHMCS: Unlimited Bandwidth
• Plesk: Unlimited Traffic
• Linux monitoring: vnStat + automation
• Fair Use Policy in Terms of Service

This gives the customer an "Unlimited" plan while still allowing you to control excessive usage without exposing hard quotas in Plesk.

 

[Thomas Oryon]

Hello @TalkBuildHost,

Thank you for your response.


Here are the details:

• Plesk Version: Plesk 18.0.79
• Operating Systems: Windows Server 2022 and Red Hat Enterprise Linux 9
• Billing System: WHMCS

Regarding bandwidth, we are referring to monthly traffic quota/data transfer, not port speed limits.


Our requirement is:

• In WHMCS, the hosting package should display Unlimited Bandwidth to customers.
• On the backend, we would like to enforce an actual monthly traffic limit on the hosting subscription/account in Plesk.
• We would like to know whether it is possible to keep the bandwidth displayed as unlimited in WHMCS while applying traffic quota restrictions within Plesk on both Windows Server 2022 and Red Hat Enterprise Linux 9 servers.

Please advise whether this setup is supported and the recommended configuration method.

Awaiting your rely

 

[TalkBuildHost]

Here are the details:

• Plesk Version: Plesk 18.0.79
• Operating Systems: Windows Server 2022 and Red Hat Enterprise Linux 9
• Billing System: WHMCS

Regarding bandwidth, we are referring to monthly traffic quota/data transfer, not port speed limits.


Our requirement is:

• In WHMCS, the hosting package should display Unlimited Bandwidth to customers.
• On the backend, we would like to enforce an actual monthly traffic limit on the hosting subscription/account in Plesk.
• We would like to know whether it is possible to keep the bandwidth displayed as unlimited in WHMCS while applying traffic quota restrictions within Plesk on both Windows Server 2022 and Red Hat Enterprise Linux 9 servers.

Please advise whether this setup is supported and the recommended configuration method.

Yes, this setup is generally possible, but it depends on how your WHMCS–Plesk integration is configured.

How WHMCS and Plesk Handle Bandwidth

WHMCS and Plesk maintain their own service definitions:

WHMCS controls what is displayed to customers in the product/package description and configurable limits within WHMCS.
Plesk enforces the actual hosting resource limits on the subscription/service plan.

Plesk supports monthly traffic (bandwidth) quotas at both the Service Plan and Subscription levels on both Linux and Windows platforms. Traffic limits are a standard Plesk resource and can be set independently of what is shown in WHMCS.

Recommended Configuration
Option 1 (Recommended): Enforce Limits in Plesk Only
In WHMCS:
Configure the hosting product to show Unlimited Bandwidth.
Do not define a bandwidth limit that would be synchronized to Plesk.
In Plesk:
Create a Service Plan with the desired monthly traffic quota (for example, 500 GB, 1 TB, etc.).
Assign subscriptions to that plan.
Plesk will track and enforce the monthly traffic usage limit.

This allows customers to see "Unlimited Bandwidth" in WHMCS while Plesk applies the actual traffic cap.

Important Consideration

If your WHMCS Plesk module is configured to provision resource limits automatically from the WHMCS package, a later package synchronization or product update could overwrite the Plesk limits.

Therefore, verify whether:

The WHMCS Plesk module maps the WHMCS "Bandwidth" field to Plesk's "Traffic" resource.
Automatic package synchronization is enabled.
Service plans are managed primarily in WHMCS or primarily in Plesk.

The safest approach is usually:

WHMCS product advertises "Unlimited Bandwidth".
Resource enforcement is managed via Plesk Service Plans.
Avoid synchronizing a bandwidth value from WHMCS to Plesk.
Platform Support

The traffic quota feature is available on:

Plesk 18.x for Windows Server 2022
Plesk 18.x for Red Hat Enterprise Linux 9

Plesk documentation and support articles show the same traffic-limit functionality for both Windows and Linux editions.

Suggested Testing

Before deploying broadly:

Create a test WHMCS product showing "Unlimited Bandwidth".
Provision a test subscription through WHMCS.
Confirm the subscription receives the intended Plesk Service Plan.
Verify in Plesk that the subscription has the desired Traffic limit.
Perform a WHMCS package sync/update and confirm the traffic limit is not overwritten.

If you can tell me:

Your WHMCS version,
Whether you're using the native Plesk provisioning module or a third-party module,
And whether you provision via Plesk Service Plans or Subscription Templates,

I can provide the exact configuration steps and identify any synchronization risks specific to your environment.