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B Mithilesh
B Mithilesh

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Understanding the Recent Airtel 5G Hotspot TTL Claims (Bypass Method included)

#airtel #hotspot #security #wecoded

Understanding the Recent Airtel 5G Hotspot TTL Claims

Over the past few days, several posts on X (formerly Twitter) have claimed that Airtel has started detecting and restricting Unlimited 5G data when shared through a mobile hotspot. One commonly shared explanation revolves around a networking concept known as TTL (Time To Live).

In this article, we'll look at what these are, how TTL actually works, and whether the explanation makes technical sense.

What is TTL?

Time To Live (TTL) is an IP header field that limits how long a packet can travel across a network. Every router that forwards the packet decreases the TTL by 1. If the value reaches 0, the packet is discarded.

Example: Laptop Connected via Mobile Hotspot 

Computer (TTL 128)
        │
        ▼
Mobile Hotspot
(TTL becomes 127)
        │
        ▼
Carrier Network
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Example: Traffic Originating from a Phone 

Phone (TTL 64)
      │
      ▼
Carrier receives TTL 64 (or close to it)
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Online ways

According to the theory:

  • Android and Linux devices typically use a default TTL of 64.
  • Windows devices commonly use a default TTL of 128.
  • When a laptop connects through a phone's hotspot, its packets allegedly arrive at the carrier with a TTL of 127.
  • The posts claim that the carrier can identify this as tethered traffic and apply hotspot restrictions.

Windows Instructions Shared in the Posts

Note: Educational purpose only.

The posts claim users can:

  1. Open Registry Editor (regedit).
  2. Navigate to: 
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
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  1. Create a new DWORD (32-bit) Value named: 
DefaultTTL
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  1. Configure the value as:
  • Base: Decimal
  • Value: 65
  1. Restart the computer.

macOS Instructions Shared in the Posts

Note: Educational purpose only.

The posts suggest running:

sudo sysctl -w net.inet.ip.ttl=65
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followed by entering the administrator password.

Final Note

The networking explanation behind TTL is based on a real IP networking concept. However, whether changing the TTL alone affects hotspot detection depends on the carrier's implementation. Modern mobile networks may use multiple techniques to identify tethering, this proof of concept works.

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