This article explains how to properly block all TeamViewer remote connections on your network. We include information from the TeamViewer port, IP address, and DNS records to block this application.
These instructions should protect you against all use of this common remote desktop application.
Corporate networks probably do not want to allow such easy remote access. How do you block TeamViewer with such a simple installation process?
DNS Block
The first step is to block the resolve of DNS records in the TeamViewer.com domain. This is easy if you run your own DNS server.
- Open your DNS administration Console
- Create a top-level record for TeamViewer.com
- Don’t do anything else. This record specifies somewhere that you do not close links to this domain and all of its subdomains.
Block TeamViewer Port
This step is perhaps not essential, but it can be as good as an extra layer of defense.
TeamViewer attaches to port 5938, but channels through ports 80 (HTTP) and 443 (SSL) if it is not available.
- Log in to your firewall or router
- Add new outbound firewall rule to discard TCP and UDP port 5938 from all source IP address.
Block Access to TeamViewer IP Address Range
The TeamViewer client will occasionally be able to connect to known IP address despite DNS records being blocked.
To stunned this, you need to block access to their IP address range.
- Log in to your firewall or router.
- Add new outgoing firewall rule to cancel connections on 178.77.120.0/24.
TeamViewer’s IP address range is 178.77.120.0/24, which translates to 178.77.120.1 – 178.77.120.254.
About Author
This is Shah Kamrujjaman Hridoy. I am a professional content writer, blogger, SEO expert, and Freelancer.
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