A multi-account team assigns a clean residential IP to each antidetect browser profile, checks the IP in a lookup page, sees the right city and ASN, and calls the setup done. Three weeks later, half the profiles are linked and restricted. The proxy was never the problem. The browser was quietly announcing the operator's real office IP through a WebRTC candidate gathering request, and every profile shared the same hidden identifier.
IP exposure inside antidetect browsers is rarely dramatic. It does not show up as a failed connection or a red warning. It shows up as correlation: two accounts that should never have met suddenly resolve to the same underlying network, and the platform's linkage model draws a line between them. WebRTC and DNS are the two most common carriers of that signal, and both bypass the HTTP proxy layer by design unless you explicitly stop them.
This guide covers how those leaks actually happen at the protocol level, how to audit each profile before it touches a real account, and which configuration choices matter versus which ones are cargo cult.
How Real IP Exposure Actually Happens
A proxy configured in a browser or antidetect profile intercepts HTTP and HTTPS requests. It does not automatically intercept every network operation the browser is capable of performing. Several subsystems can open their own sockets, use their own resolvers, or prefer a different address family, and each one is a potential exit around your proxy.
WebRTC and the ICE Candidate Problem
WebRTC exists to let browsers establish direct peer connections for voice, video, and data. To do that it needs to know how the machine can be reached, so it runs ICE (Interactive Connectivity Establishment) candidate gathering. The browser enumerates local network interfaces, then contacts STUN servers to discover its public address as seen from outside.
That STUN traffic is typically UDP. An HTTP proxy cannot carry it. If the antidetect browser has not been configured to block, spoof, or route WebRTC, the STUN request goes out over the host's default route and returns the host's real public IP. Any page with JavaScript can read those candidates without permission prompts, because candidate gathering is part of establishing a connection, not part of accessing a camera.
There are three classes of exposure here. Public IP disclosure happens when a STUN response reveals the host address behind the proxy. Local IP disclosure reveals private addresses such as 192.168.x.x or a stable mDNS hostname, which is less damaging on its own but valuable as a correlation key across profiles. Interface enumeration reveals how many network adapters exist, which is itself a fingerprint characteristic when it stays identical across supposedly unrelated identities.
Modern Chromium builds obfuscate local candidates using randomised mDNS hostnames, which helps. It does nothing about the public candidate returned by STUN.
DNS: The Question of Who Resolves the Hostname
Every request begins with a name lookup, and the resolver that performs that lookup sees the domain you are about to visit. If your browser resolves names locally and only then sends the request through the proxy, your ISP resolver holds a log of your target list, and the target site sees a mismatch between the visitor IP and the resolver's geography.
With HTTP proxies and with SOCKS5h, the proxy performs resolution remotely, which is what you want. With plain SOCKS5 configured for local resolution, the client resolves first. Many libraries and some antidetect profiles default to local resolution unless told otherwise, and this is one of the most common silent misconfigurations in multi-account infrastructure.
The detection consequence is subtle but real. Anti-fraud systems increasingly compare the resolver network observed via EDNS client subnet or via authoritative DNS logs against the connecting IP. A residential IP in Munich paired with a resolver in a datacenter in Virginia is an inconsistency, and inconsistency is the currency of bot detection.
Secure DNS features complicate this further. If the browser has DNS over HTTPS enabled with a hardcoded provider, it may bypass both the system resolver and, depending on implementation, your proxy's resolution path. Encrypted does not mean proxied.
IPv6 as the Silent Bypass
If the host has working IPv6 connectivity and the proxy is IPv4 only, dual-stack resolution can hand the browser an AAAA record and a direct route that never touches the proxy. The session looks fine, the page loads fine, and the target logs a completely different address from the one you provisioned. This is easy to miss because most IP lookup pages report whichever family they were reached on, so a quick check can show the proxy IP while a second request over IPv6 tells a different story.
Non-Browser Leak Sources
Extensions, update checks, telemetry endpoints, and any bundled automation runtime can hold their own network configuration. A scraping script launched alongside a profile may inherit system settings rather than the profile proxy. Timezone, locale, and geolocation API values are not IP leaks, but a mismatch between them and the proxy exit produces the same outcome: a profile that looks assembled rather than lived in.
A Repeatable Leak Audit Workflow
Auditing is not a one-off. Every new profile, every proxy pool change, and every browser update deserves a pass. The goal is a checklist short enough that operators actually run it.
Step one: baseline the host. Record the real public IPv4 and IPv6 addresses of the machine and any VPN it sits behind. You cannot recognise a leak if you do not know what your own address looks like.
Step two: verify the proxy exit in isolation. Before launching any profile, confirm the credentials work, the exit geography matches the intended market, and the address family is what you expect. Running the endpoint through a proxy tester first separates provider problems from browser problems, which saves a lot of misdirected debugging.
Step three: check the HTTP layer. Load an IP echo endpoint inside the profile and confirm the reported address matches the assigned exit, then check the reported ASN type. A residential exit that reports as hosting infrastructure is a pool quality issue, not a leak, but you want to know now.
Step four: gather ICE candidates deliberately. Use a WebRTC test page that lists all candidates rather than one that only prints a summary. You are looking for any srflx (server reflexive) candidate containing your baseline public IP, and any host candidate exposing a stable private address. If the antidetect browser claims to spoof WebRTC to match the proxy, verify that the spoofed value equals the proxy exit and not a random unrelated address, because a mismatch between the HTTP IP and the WebRTC IP is itself suspicious.
Step five: test DNS resolution path. Use a DNS leak test that reports the resolvers observed, then compare the resolver country and network against the proxy exit. Multiple resolvers from unrelated networks is normal for some providers. A resolver sitting in your own ISP's range is not.
Step six: force the IPv6 question. Visit an IPv6-only test host from inside the profile. If it loads and reports an address, you have a route that bypasses an IPv4 proxy. Either disable IPv6 on the profile or use a proxy pool that handles both families coherently.
Step seven: re-test under load. Leaks appear during failover. When a proxy times out and the browser or an extension retries, some stacks fall back to a direct connection. Simulate a dead proxy by pointing the profile at an unreachable port and confirm the profile fails closed rather than silently loading the page.
Document the results per profile with a timestamp. When an account gets flagged two months later, that log is the difference between a diagnosis and a guess.
Hardening Configuration Without Breaking Realism
The instinct is to disable everything. That instinct is wrong. A browser with WebRTC fully removed is unusual, and on platforms that expect video calling capability, absence is its own anomaly.
Prefer replacement over removal. Most serious antidetect browsers offer a WebRTC mode that reports the proxy IP as the public candidate while suppressing local interface disclosure. That produces a consistent story: HTTP, WebRTC, timezone, and geolocation all agree.
Use remote DNS resolution everywhere. For SOCKS5 endpoints, that means the variant that delegates resolution to the proxy. Disable browser-level secure DNS inside profiles unless you have confirmed it routes through the proxy.
Keep one proxy per identity and keep it sticky. Session control matters more than raw rotation speed for account work, and a stable exit removes an entire category of inconsistency.
Run the audit on the machine that will do the work. A profile validated on a developer laptop and then cloned to a VPS behaves differently because the host network differs.
Where Proxies Fit In: Leak Resistance Starts With Pool Design
Browser configuration only controls what leaks. The proxy layer controls what is exposed when nothing leaks at all, and that is where pool design becomes an audit concern rather than a purchasing one.
Three properties do most of the work. Coherent address family support means the endpoint behaves predictably on IPv4 and IPv6 so you are not forced into blanket IPv6 disabling. Reliable remote resolution means DNS queries genuinely exit alongside the traffic, keeping resolver geography aligned with the visible IP. Session control means a profile can hold the same exit long enough for its behavioural history to look continuous, with rotation applied on your terms rather than the network's.
This is where provider selection stops being about advertised pool size. EnigmaProxy operates multiple pool types (residential, ISP, datacenter, and mobile) with ethically sourced peer networks and broad geo-coverage, which matters here for a practical reason: matching pool type to profile purpose removes the temptation to reuse one endpoint across identities. Business-grade reliability also reduces failover events, and failover is precisely when leak-prone fallback paths get exercised.
For teams running dozens of profiles, predictable pricing across pool types makes it realistic to assign dedicated endpoints per identity instead of sharing, which is the cheapest correlation fix available.
Strategic Insights: Where Leak Detection Is Heading
Passive correlation is replacing active probing. Rather than asking the browser for a WebRTC candidate, platforms increasingly correlate signals over time: resolver networks, TLS characteristics, timing, and address family behaviour. A single clean audit will matter less than consistency across weeks.
Encrypted DNS becomes the default battleground. As DNS over HTTPS and Oblivious DNS spread, the question shifts from whether DNS is encrypted to whose network terminates the query. Teams that treat resolution as part of proxy configuration rather than a browser preference will stay ahead.
IPv6 stops being optional. As more targets serve IPv6 natively, disabling it wholesale becomes its own anomaly. Proxy infrastructure that handles dual-stack coherently will be the practical requirement, not a nice-to-have.
Auditing becomes automated policy. The mature pattern is a pre-flight check that runs on profile launch, verifies exit IP, WebRTC candidates, resolver geography, and address family, then refuses to open the profile if any check fails. Manual checklists do not survive contact with a team of ten operators.
Conclusion
A proxy that returns the correct city in an IP lookup has proven exactly one thing: that HTTP traffic is routed. WebRTC candidate gathering, local DNS resolution, and dual-stack IPv6 routes each operate outside that path, and any one of them can hand a platform the correlation key it needs to link an entire portfolio of accounts.
The fix is unglamorous. Baseline your host, verify the endpoint separately from the browser, inspect ICE candidates rather than summaries, confirm resolver geography, force an IPv6 test, and check that the profile fails closed when the proxy dies. Then log it, because the value of an audit is comparative.
Combine that discipline with proxy infrastructure that supports genuine session control and coherent resolution, and leak prevention becomes a property of the system rather than a habit you hope everyone remembers. Providers positioned in the professional tier, EnigmaProxy among them, give multi-account teams the pool diversity and geo-coverage to keep every identity on its own consistent network path.