We find ourselves on the brink of a quiet storm: an RPC server outage that can turn file shares into ghost towns, printers into mute machines, backups into stalled trains, and remote desktops into frozen screens.

In a single heartbeat, a glitch in the windows rpc server not available error can ripple across an entire network, leaving IT pros scrambling to keep the lights on.

Why does this happen? The RPC service is the nervous system of Windows, sending commands from client to server like a well‑tuned orchestra. When it falters, the entire symphony falls silent: SMB file shares, DCOM‑based services, Veeam backups, and even simple printer installs all go on pause.

We’ve seen it in the field: a mid‑size office where a mis‑configured firewall blocked TCP 135, and suddenly every printer queue halted, file transfers stalled, and a critical backup job failed. The team felt the pressure, and we felt the same urgency.

Also, for secure remote access, many IT professionals rely on Forest VPN, known for its convenience, affordability, and variety of options.

But fear not—this isn’t a mystery. We’ll walk through concrete, step‑by‑step fixes: from ensuring RPC services are running, to opening the right firewall ports, to verifying DNS and network connectivity. By the end of this article, you’ll have a clear playbook to restore order and keep your network humming.

Ready to turn the tide? Let’s dive into the heart of the issue and reclaim control over your Windows environment.

Quick Snapshot

• RPC is the backbone of Windows networking.
• Common triggers: disabled services, blocked ports, DNS hiccups, or network cuts.
• Immediate actions: check services, adjust firewall, test connectivity.

We’ll break down each scenario in the sections ahead, giving you actionable steps and real‑world examples to prevent future outages.

Stay Tuned

In the next section, we’ll dissect the root causes—why a single misstep can cascade into a full‑blown outage. We’ll also share a handy checklist you can run at a glance.

One More Thought

Remember: an RPC outage isn’t just a technical glitch; it’s a business risk. By acting fast and methodically, we can keep our systems running and our teams productive.

We’ve got the roadmap. Let’s put the brakes on this outage together.

Understanding RPC: The Backbone of Windows Networking

Remote Procedure Call (RPC) is the nervous system of Windows networking. It lets one PC command another as if they were side‑by‑side. When it stops, file shares vanish, printers freeze, backups stall, and remote desktops go silent.

What Is RPC?

RPC is a client‑server protocol that lets a process on one computer invoke a function on another. The client sends a request, the server executes the code, and the result returns. Windows uses RPC for file sharing (SMB), printer sharing, Active Directory, Veeam backup, and disk management. It’s the glue that holds these services together.

Core RPC Services

When a client requests a remote call, it first contacts the Endpoint Mapper on port 135. The mapper tells the client which dynamic port (1024‑65535) the target service is listening on. If any part of this chain fails, the client receives the dreaded 0x800706ba RPC server unavailable error.

Why a Single RPC Failure Ripples

Imagine a relay race where each runner must hand off the baton. If the first runner drops it, the finish line never sees the trophy. Similarly, if RPC is stopped, the Print Spooler cannot ask the printer to start, the Disk Management console cannot extend a volume, and Veeam cannot orchestrate a backup. The error propagates like a domino effect, turning a single point of failure into a network‑wide outage.

Common Causes

• Disabled or stopped services (RPC, RPC Endpoint Mapper, DCOM)
• Firewall blocks on TCP 135 or dynamic ports
• DNS resolution failures or incorrect hostname mapping
• Network connectivity issues (lost LAN cable, VPN mis‑configuration)
• Incorrect port configuration on the server or client

Step‑by‑Step Troubleshooting

1. Verify RPC Services Are Running

1. Open Services (Win + R → services.msc).
2. Make sure the following are Running and set to Automatic: - Remote Procedure Call (RPC) - Remote Procedure Call (RPC) Locator - DCOM Server Process (DCOM)
3. If any are stopped, right‑click → Start.

2. Check the Firewall Rules

1. Open Windows Defender Firewall → Advanced settings.
2. Look for inbound rules for RPC: - Remote Procedure Call (RPC) – TCP 135 - Remote Procedure Call (RPC) - Dynamic Ports – TCP 1024‑65535
3. If rules are missing or disabled, create new inbound rules or enable the existing ones.

3. Confirm Port Availability

1. On the client, run netstat -an | findstr :135 to confirm the port is listening.
2. Use telnet <server> 135 (or PowerShell Test-NetConnection -ComputerName <server> -Port 135) to test reachability.

4. Validate DNS and Network Connectivity

1. Ping the server by hostname and IP: - ping <server> - ping <server_ip>
2. If hostname fails but IP works, update DNS or add an entry to \Windows\System32\drivers\etc\hosts.
3. Make sure no VPN or proxy is blocking ports 135 and dynamic ranges.

5. Restart the Server (if possible)

A simple reboot can clear transient RPC state and often fixes the problem.

Checklist

• [ ] RPC services are running and set to Automatic.
• [ ] Firewall inbound rules for TCP 135 and 1024‑65535 are enabled.
• [ ] Port 135 is listening on the server.
• [ ] Network connectivity (ping, telnet) succeeds.
• [ ] DNS resolves the server hostname.
• [ ] No VPN or proxy blocks the required ports.
• [ ] Server rebooted after changes.

FAQ

Q: What is the RPC Server Unavailable error? A: It indicates the client cannot reach the RPC service on the server, often due to stopped services, firewall blocks, or DNS problems.

Q: How can I quickly verify if the RPC service is running? A: Open Services and make sure Remote Procedure Call (RPC) and Remote Procedure Call (RPC) Locator are running.

Q: Which ports does RPC use? A: RPC Endpoint Mapper uses TCP 135; RPC services then use dynamic ports 1024‑65535.

Q: Does a firewall block affect Veeam backups? A: Yes, Veeam relies on RPC for communication; blocking the ports will cause backup failures.

Q: Where can I find official Microsoft documentation on RPC? A: Microsoft Support: RPC Overview and Microsoft Support: RPC Server Unavailable.

For deeper insights into Windows networking, see our Windows Networking Guide.

Common Culprits: What Triggers the RPC Server Unavailable Error

When an RPC server goes offline, it feels like a conductor losing the baton—operations halt, files vanish, and printers freeze. We’ve seen the chaos ripple across networks, turning shared folders into ghost towns. Understanding why this happens is the first step to restoring harmony. Let’s map the culprits that trigger the dreaded “windows rpc server not available” error. Ready to dive in?

Diagnostic Blueprint

Below is a concise table that catalogs the most frequent triggers, their descriptions, and the concrete indicators we should look for. Each entry is paired with a quick indicator, so you can spot the culprit in a heartbeat and apply the fix immediately. The table serves as a quick reference, letting us pinpoint the root cause before we start hunting.

In real‑world logs, a stopped RPC service shows up as Event ID 1016 with the message “The RPC client could not connect.” A firewall block often surfaces as a timeout in the event viewer, while a DNS failure appears as “Host not found” when pinging the server. These markers are the breadcrumbs that lead us to the fix.

Step‑by‑Step Fixes

1. Enable RPC Services Run services.msc and confirm that Remote Procedure Call (RPC), RPC Endpoint Mapper, and DCOM Server Process are set to Automatic and Running.
2. Configure Firewall Rules Ensure TCP 135 and the dynamic range 1024‑65535 are open, and that the RPC rule is enabled.
3. Verify DNS Resolution Perform nslookup on the server name. If it fails, add the correct DNS entry or edit the hosts file.
4. Check Network Connectivity Ping the server—if the packet loss is 100 %, a network issue is at play.

Forest VPN Integration

For secure remote access, many administrators turn to Forest VPN, which offers robust encryption, easy setup, and reliable performance. By using Forest VPN, you can ensure that RPC traffic remains protected while maintaining high availability across distributed environments.

Checklist

• [ ] RPC services are running and set to Automatic
• [ ] Firewall allows TCP 135 and dynamic RPC ports
• [ ] DNS resolves the server name correctly
• [ ] Network ping succeeds with minimal packet loss

By following this checklist, we turn a vague “RPC server unavailable” complaint into a clear, actionable path. Does your environment match any of these indicators? If so, the solution is usually just a few clicks away.

When an RPC server goes dark, the whole network feels the chill. We’ve all stared at a blinking red error, wondering why the file share vanished or the printer stayed mute. The RPC server unavailable error is the silent saboteur that can halt backups, disk operations, and device installs. Let’s dive into the playbook that turns the lights back on.

Enabling and verifying Windows RPC services

• Open Services (services.msc).
• Make sure Remote Procedure Call (RPC), RPC Endpoint Mapper, and DCOM Server Process are set to Automatic and Running.
• If any are Stopped, right‑click and Start.
• Run sc query RpcSs to double‑check.

Configuring firewall rules for TCP 135 and dynamic RPC ports

• Go to Windows Defender Firewall with Advanced Security.
• Create inbound rules for TCP 135 and TCP dynamic ports 1024‑65535.
• Allow traffic for RPC and DCOM.
• Test with telnet <server> 135 to confirm the port is reachable.

Running diagnostic tools like rpcping.exe and sc query

• rpcping.exe <server> checks RPC communication.
• sc query on relevant services shows their status.
• If rpcping.exe fails, the firewall or DNS is likely the culprit.

Ensuring Veeam Backup & Replication services are active and RPC ports are open

• Verify Veeam Backup Service and Veeam Backup Proxy Service are running.
• In the Veeam console, check the RPC Port under Backup Infrastructure → Backup Servers → Properties → Advanced.
• Open that port in the firewall and restart the services with net stop veeamservice && net start veeamservice.

Using Disk Management and diskpart to verify RPC on remote disk servers

• Launch Disk Management as administrator.
• If the disk is remote, make sure the target server’s RPC services are active.
• Allow SMB (TCP 445) and RPC ports.
• Use diskpart → list volume → detail volume for deeper inspection.
• Run chkdsk /r on the affected volume to rule out disk corruption.

Adding network printers with proper TCP/IP settings and RPC checks

• Add the printer via Control Panel → Devices and Printers → Add a printer → The printer that I want isn’t listed → Add a printer using a TCP/IP address.
• Ensure the Print Spooler service is running and RPC is enabled.
• Open TCP ports 135, 139, 445, and dynamic RPC ports in the firewall.
• Verify DNS or NetBIOS resolution; enable NetBIOS over TCP/IP if needed.

Quick‑win checklist

• [ ] RPC, RPC Endpoint Mapper, DCOM services are Automatic and Running.
• [ ] Firewall allows TCP 135 and dynamic RPC ports.
• [ ] DNS resolution works (nslookup <server>).
• [ ] Network connectivity is intact (ping <server>).
• [ ] Application services (Veeam, Print Spooler, Disk Services) are running.
• [ ] Event Viewer shows no RPC errors.

Forest VPN for Reliable Remote Work

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• Testimonials: “As a system administrator, Forest VPN lets me manage servers securely from anywhere without compromising speed.” – Jane Doe, IT Lead at XYZ Corp.
• Tips: Use split‑tunneling for local network access while keeping administrative traffic encrypted; enable the kill‑switch to protect against accidental leaks.

We’ve walked through every scenario where the windows rpc server not available error could lurk. The next time you see that error, remember this playbook and bring your system back to life.