Why Your Mobile Proxy IP Sometimes Does Not Change (Pool Pressure)

A message we see in support fairly often reads: I rotated and the IP did not change. It is a reasonable thing to worry about, and it is almost never the modem, the SIM or the proxy at fault. What you are seeing is the behaviour of a finite carrier pool under a particular amount of load at a particular moment. This page explains, calmly and in order, why a carrier sometimes hands a line the address it just released, what pool pressure means, how session timers on the carrier side interact with your rotation, what our team looks at when you raise it, and how to get a genuinely fresh address when the job requires one.

What a rotation actually does

On an EliteProx line, a rotation is a physical event on dedicated hardware. The modem drops its data session with the carrier, waits briefly, and attaches again. During that gap the public address it was using goes back to the pool behind the carrier gateway for that metro. On re-attach the gateway assigns an address from that same pool. Nothing in that process guarantees a different address. The gateway is not trying to give you a new one; it is simply handing out whatever is free, and the address you just released is, at that instant, free.

This is worth holding onto because it reframes the question. The proxy did rotate. The session was torn down and rebuilt, which is all a rotation can ever be on a real SIM. Whether the address changes is decided by the carrier, based on what else is happening on that gateway at that second.

Pool pressure: the quiet pool and the busy pool

Think of the gateway pool as a set of addresses being borrowed and returned by every phone in the area, all the time. On a busy pool, the moment your modem detaches, some other device attaches and takes the address you released. When you re-attach a few seconds later it is gone, and you get another. On a quiet pool nobody takes it in that window, and the gateway, seeing the same SIM come back, gives it the address it had. Both outcomes are the pool working correctly.

The quiet case is what most people are describing when they say the IP does not change. Time of day matters; overnight in a smaller metro a pool can be very calm. Carrier matters; in our racks Verizon lines tend to hand out a fresh address readily, AT&T lines tend to be stickier and revisit addresses more often, and T-Mobile varies a good deal from one metro to the next. Metro matters even on the same carrier, because each gateway is its own pool with its own load. The exact behaviour of any line depends on carrier, city and how often you rotate, and our team can tell you which line in a given city is currently rotating freshest.

Session timers: the carrier's own clock

There is a second mechanism that has nothing to do with your rotation button. A carrier lets an active data session keep its address for a certain time, often days or weeks, and some networks reset sessions on a timer of their own. This sets the ceiling on how long a sticky address can last: you can hold an address as long as you like, carrier permitting, but the carrier can eventually reassign it during a session reset. The floor, at the other end, is the modem's re-attach cycle, which takes seconds.

Between those two you control everything. Nothing on our side rotates your address on a schedule, and nobody is forced to rotate every thirty seconds. Fast churn is always the customer's own timer. If you see the address holding steady for days, that is the carrier honouring a session. If you see it holding through a rotation, that is a quiet pool. Neither is the hardware misbehaving.

Why an unchanging address is usually a feature

For much of the work our customers do, a stable address is exactly what they paid for. An aged social account, a seller account, a long-running research session with a login: all of these want the same address today that they had yesterday, on the same carrier, in the same city. A platform that sees consistent geography and a carrier ASN for an account has every reason to trust it. A line that hands back the same address after a brief detach is behaving like a well-mannered phone that lost signal in a lift and got it back.

It only becomes a problem when the job wanted freshness: a verification run, a research batch where each pass should arrive from a new address, or a scrape where an address has already been used heavily. In those cases the same address returning is a signal to change approach, not a fault to raise. We tell the two apart by asking what you were trying to do, which is why the first question from support is usually about the job rather than about the modem.

What our team checks when you raise it

When a customer tells us the address is not changing, we look at a short list, in order. It rarely gets past the first two items.

Two of these have direct remedies on our side. We can lengthen the detach duration so the modem stays offline long enough for another device to take the address, and we can rotate the line ourselves to confirm the pool is responding. If the pool in that metro is quiet for that carrier, the honest fix is a different carrier or a different city, and both moves are free.

• That the rotation actually completed: the modem detached and re-attached, which shows in the line's session state
• How long the modem stayed detached, since a very short gap on a quiet pool gives the carrier no reason to reassign
• How busy that carrier's gateway is in that metro right now, judged from how the other lines in the same rack are behaving
• Whether the address has been held by a long-running session and the carrier is simply honouring it
• Whether a different carrier or metro would give the freshness the job needs

How to get a fresh address when you need one

If your job needs freshness right now, the sequence is simple. Rotate again; on a quiet pool a second attempt often lands elsewhere. If it returns the same address, wait a little longer before the next attempt, since the point is to give another phone the chance to take the address during the gap. If it keeps coming back, ask us to extend the detach time or to move you to a carrier in that metro that is handing out addresses freely today. For a job that needs a new address on every pass, the right tool is a line chosen for yield, on a carrier and metro where the pool is busy, rotated at a cadence that matches the pool rather than as fast as the modem allows. Rotating faster than the pool turns over only churns the same handful of addresses.

A few hundred distinct addresses in a week and low thousands over a quarter is a reasonable expectation for a single line rotated many times a day, with discovery fastest early and slowing as the line has seen most of what its gateway hands out. Use that as a rule of thumb, not a promise, and check it against your own line on your own target.

What to do next on EliteProx

Test on the real target, not on a checker. If the address holds and the job wanted it to hold, you are done. If it holds and you wanted change, rotate again, wait a little longer, then open the live chat and tell us the carrier, the city and the job. Priority support will check the session state, adjust the detach duration if that is the issue, and tell you which line in your city is rotating freshest today. Switching carrier or moving the proxy to another of our eight metros, from New York to Miami, is free and takes minutes, because the hardware is ours.

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