What is the significance of the 127.0.0.1 IP address in sign-in logs?

Question

What is the significance of the 127.0.0.1 IP address in sign-in logs?

Jean Paul Nkundabose 110

In my sign-in logs, I noticed the IP address 127.0.0.1. What is the meaning of this IP address, and why is it showing up in my logs?

JamesTran-MSFT 37,246 Reputation points Microsoft Employee Moderator

2023-12-05T20:23:14.38+00:00

@Jean Paul Nkundabose

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If you have any other questions, please let me know. Thank you for your time and patience throughout this issue.

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JamesTran-MSFT 37,246 Reputation points Microsoft Employee Moderator

2023-12-05T20:23:14.38+00:00

@Jean Paul Nkundabose

I wanted to check in and see if you had any other questions or if you were able to resolve this issue?

If you have any other questions, please let me know. Thank you for your time and patience throughout this issue.

If the information helped address your question, please Accept the answer. This will help us and also improve searchability for others in the community who might be researching similar information.

Answer 1

Jarvis Sun-MSFT 10,286 Microsoft External Staff

Hi @Jean Paul Nkundabose ,

Welcome to our MS Q&A forum!

The IP address 127.0.0.1 is called the loopback address and is used by a computer to refer to itself. It is also known as localhost. When a server is running on your local PC, it will be accessible at 127.0.0.1. This IP address is reserved for loopback purposes and is not used to communicate with other devices like a real IP address.

It is possible that you are seeing this IP address in your sign-in logs because your device is trying to connect to a service running on your local machine.

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Jean Paul Nkundabose 110 Reputation points

2023-11-30T19:53:30.4433333+00:00

Hi Jarvis,

You stated "It is possible that you are seeing this IP address in your sign-in logs because your device is trying to connect to a service running on your local machine.", this ip is found in non-interactive sign-ins and user signing in Exchange online service. can you please clarify in details?
Jarvis Sun-MSFT 10,286 Reputation points Microsoft External Staff

2023-12-01T05:50:18.91+00:00

Hi @Jean Paul Nkundabose , thanks for your reply.

If convenient, could you please provide more detailed information about the IP in the sign-in logs?

Based on my experience, this could happen if you are running a local server or if you are using a VPN.
Jean Paul Nkundabose 110 Reputation points

2023-12-01T12:46:14.81+00:00

Not sure what other details you need. As you stated it is loop back IP associated with user’s computer. The question is “how come this IP show in sign-ins logs instead of the real IP?
Jarvis Sun-MSFT 10,286 Reputation points Microsoft External Staff

2023-12-04T08:15:06.6866667+00:00

@Jean Paul Nkundabose ,

I don't see any127 address in my environment, so can you provide a screenshot? Does it address appear a lot, and are you using any proxy software?
Jeremie Ndala 0 Reputation points

2025-02-13T21:45:15.9033333+00:00

Hi, I try to connect to a server on my computer but it does'nt work. what can be the issue? http://localhost:30304/

Answer 2

It is a loopback address called localhost (127.0.0.1) used for testing particular apps' tasks on the same device you are currently using without connecting to an external device or internet connection.

Ports, such as 49342, 57573, and 62893, are added to the end of the localhost (e.g., https://100001.pw/127001-49342-57573-and-62893) to route data to specific services or applications locally.

127.0.0.1 on your login log may be because an app uses it to test or view particular pages on your local device without sending or receiving any data from a third-party.

Or it may be a malware trying to exploit them for harmful activities. It is always better to scan your website with a anti-virus programme.

Answer 3

Anik Pal 10

The IP address 127.0.0.1 is called the loopback address and is used by a computer to refer to itself. It is also known as localhost. When a server is running on your local PC, it will be accessible at 127.0.0.1. This IP address is reserved for loopback purposes and is not used to communicate with other devices like a real IP address.

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Answer 4

Eng. Abu Ayoub /Eng. Reshad Ahmed/ 10

Not now i will come back again at any time

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What is the significance of the 127.0.0.1 IP address in sign-in logs?

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