How Swiss Mobile IPs Work (And Why They’re Different)

The Swiss Mobile IP Anomaly

In most countries, disconnecting and reconnecting to a mobile network typically results in a new IP address assignment. It’s a behavior many users expect and even rely on for privacy or troubleshooting purposes. However, in Switzerland, the opposite is true: your mobile device will likely receive the same IP address even after network reconnections, sometimes for hours or even days.

This “sticky IP” behavior isn’t a bug – it’s a feature of how Swiss mobile networks are designed and operated. To understand why, we need to dive into the technical architecture that powers Switzerland’s mobile internet infrastructure.

The CGNAT Foundation

All three major Swiss mobile operators – Swisscom, Sunrise, and Salt – employ Carrier-Grade Network Address Translation (CGNAT) as their standard approach to IPv4 address management. This technology emerged as a response to IPv4 address exhaustion, a global problem that became particularly acute in the mid-2010s.

Here’s how it works in practice:

• Your smartphone doesn’t receive a public IPv4 address directly
• Instead, it gets a private IP address from ranges like 10.x.x.x or 100.64.0.0/10
• The carrier’s CGNAT equipment translates your private address to a shared public IP
• Multiple customers (often dozens) share the same public IP address simultaneously

This architecture explains why tools like “What’s My IP” show a different address than what’s configured on your device, and why hostnames often reveal the CGNAT nature with names like dynamic.cgnat.res.cust.swisscom.ch.

IMSI-Based IP Assignment

Through extensive testing and research, we’ve uncovered the core mechanism behind Swiss mobile IP persistence – and it’s more sophisticated than typical session management. The key lies in how Swiss operators handle IMSI (International Mobile Subscriber Identity) recognition and IP assignment.

The IMSI Foundation

Every SIM card contains a unique IMSI – a 15-digit identifier that’s even more fundamental than a device’s IMEI number. Unlike IMEI, which identifies the hardware, IMSI identifies the subscriber and cannot be modified or influenced by the user. Our testing has confirmed that this IMSI serves as the primary key for IP assignment in Swiss networks.

Provider-Side IP Mapping

Here’s where Swiss networks differ fundamentally from other countries: when a SIM card (identified by its IMSI) first connects to the network, the provider doesn’t just assign an IP from the available pool – it creates a persistent mapping between that IMSI and the assigned IP address. This mapping is stored provider-side and remains active far longer than in other networks.

Our research revealed several critical behaviors:

• Device Independence: The same SIM card produces the same IP address regardless of which device it’s inserted into
• IMEI Emulation Ineffective: Even when using ADB (Android Debug Bridge) commands to modify device identifiers, the IP remains unchanged because the network relies on IMSI, not IMEI
• Extended Persistence: IP addresses remain consistent even after:
  • Airplane mode cycling
  • Device reboots
  • Network disconnections lasting over an hour
  • Manual network resets via ADB commands

PDP Session Architecture

The Packet Data Protocol (PDP) session establishment in Swiss networks follows this IMSI-based approach:

1. Initial Connection: Device presents IMSI to network
2. Database Lookup: Provider checks if this IMSI has a previous IP assignment
3. Assignment Logic: If found, the same IP is reassigned; if new, an IP is selected and mapped
4. Session Creation: PDP context is established with the predetermined IP
5. Persistent Storage: The IMSI-to-IP mapping is maintained provider-side

Why User-Side Disconnection Fails

Unlike networks in other countries where a simple reconnection can trigger a new PDP session with different parameters, Swiss networks maintain authoritative control over IP assignments. The PDP session cannot be “cleanly” terminated from the client side to force IP rotation because:

• The network recognizes the returning IMSI
• Previous IP assignments take precedence over new allocation requests
• Session termination doesn’t clear the provider-side IMSI-IP mapping
• Multiple devices can share the same public IP through CGNAT, but each IMSI maintains its consistent private IP assignment

The Unique Value of Swiss IPs

While the persistent IP behavior of Swiss mobile networks might seem like a limitation, it has actually created a unique value proposition that sets Swiss mobile IPs apart in the global proxy market.

Platform-Optimized Infrastructure

Major platforms have specifically optimized their systems for Swiss mobile traffic patterns, assigning higher trust scores to Swiss mobile CGNAT ranges because:

• Consistent user base creates predictable, legitimate traffic patterns
• Platforms understand blocking affects large numbers of real users
• These ranges aren’t associated with throwaway proxy usage

This results in lower automatic blocking rates, more sophisticated behavioral analysis, and better tolerance for higher request volumes.

The “Verified Legitimacy” Effect

Swiss mobile IPs benefit from “verified legitimacy” status with years of legitimate traffic history, consistent behavioral patterns that mimic genuine users, and strong geographic consistency valued for compliance.

The combination of technical reliability, platform recognition, and behavioral predictability creates a “Swiss mobile IP premium” offering:

• Higher success rates for long-term projects
• Better compatibility with strict anti-bot systems
• Reduced need for sophisticated rotation strategies
• Natural compliance with platform policies

This makes Swiss mobile IPs particularly valuable for users who prioritize reliability and legitimacy over rapid IP rotation.

Mobile Proxy Use Case Impacts

Social Media Management

Advantages: Reduced account suspension risks, fewer security checks, consistent addresses don’t disrupt algorithms.Considerations: Shared CGNAT requires careful rate limiting.

E-commerce & Price Monitoring

Advantages: Fewer CAPTCHAs, stable geo-targeting, ideal for extended monitoring campaigns. Considerations: Shared IPs may hit rate limits faster.

SEO & SERP Analysis

Advantages: Consistent search results, reduced blocking, stable geographic positioning. Considerations: More trackable footprint over time.

Ad Verification

Advantages: Mimics real user behavior, optimized ad network systems, lower anti-fraud triggers. Considerations: CGNAT sharing may affect attribution accuracy.

Market Research

Advantages: Sustained access, encourages ethical practices, reliable positioning. Considerations: Limited geographic flexibility within Switzerland.

Content Testing

Advantages: Stable A/B testing environment, eliminates geographic variables. Considerations: Cannot test different Swiss regions easily.

Conclusion

Swiss mobile networks’ persistent IP behavior reflects a unique approach to managing scarce IPv4 resources while prioritizing user experience and operational efficiency. While this creates challenges for users expecting frequent IP rotation, it also provides benefits in terms of session stability and connection consistency.

The key takeaway? Swiss mobile IPs are different by design, not by accident. This persistence is a feature that reflects the operators’ priorities and technical constraints – and knowing how to work with (or around) these characteristics can make the difference between successful and frustrating mobile connectivity experiences.