Network tunneling is the technique of encapsulating packets of one protocol inside packets of another, so they can travel across a network that does not natively support the inner protocol or that you do not trust. At the far end the outer wrapper is removed and the original packet continues.
Why it matters
Tunnels connect private networks across the internet, carry IPv6 over IPv4 infrastructure, and let a remote user appear to be inside an office network. Many tunnels add encryption (IPsec, WireGuard), but encapsulation by itself provides no privacy. The cost is overhead: extra headers shrink the usable payload per packet, which interacts with MTU and may cause fragmentation.
Example
A branch router wants to reach 10.1.0.0/16 at headquarters over the internet. It wraps each private packet in a new IP packet addressed to the headquarters' public address. Routers on the internet see only the outer header; the headquarters router strips it and delivers the inner packet.
[outer IP][tunnel header][inner IP][payload]Common mistakes
- Assuming a tunnel is encrypted; GRE, for example, is not.
- Forgetting to lower the inner MTU, so large packets stall.
- Tunneling prohibited traffic through a firewall in a way that bypasses security policy, such as over DNS or HTTPS.
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यह पेज सामान्य जानकारी है, जिसे हमारी संपादकीय टीम ने लिखा है और दस्तावेज़ीकरण बदलने पर अपडेट किया जाता है। सर्वर और प्रदाता अलग-अलग होते हैं, इसलिए बदलाव पहले सुरक्षित तरीके से जाँचें। देखें: संपादकीय नीति और अस्वीकरण.