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Questions tagged [loopback-address]

Loopback address is a special IP number (127.0.0.1) that is designated for the software loopback interface of a machine.

Loopback address, based upon RFC 5735: Special Use IPv4 Addresses, is a special IP number (eg: 127.0.0.1) that is designated for the software loopback interface of a machine. The loopback interface has no hardware associated with it, and it is not physically connected to a network.

Within IPV6 loopback looks like 0:0:0:0:0:0:0:1, although in IPV6, the longest contiguous block of zeros may be replaced with :: thus resulting in the condensed loopback address of ::1, based upon RFC 4291: IP Version 6 Addressing Architecture.

Looback address is a special range of addresses in the range 127.0.0.0 to 127.255.255.255. The data sent by a host to a 127.x.x.x loopback address are not passed down to the data link layer for transmission. Instead, they “loop back” to the source device.

The purpose of the loopback range is testing of the TCP/IP protocol implementation on a host. Since the lower layers are short-circuited, sending to a loopback address allows the higher layers (IP and above) to be effectively tested without the chance of problems at the lower layers manifesting themselves. 127.0.0.1 is the address most commonly used for testing purposes.

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Loop back address

When i ping 127.0.0.1 and any address of 127 series(except 127.0.0.0 and 127.255.255.255),i am not finding any difference.Can anyone comment on this?
svkvvenky
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How does the VIP loopback aliase work?

I want to know how does the loopback alias work,lets say i have the following nodes: n[1-10] on a load balancer, all under the following VIPs : xx.xx.xx.xx yy.yy.yy.yy on the nodes we have the following: lo:0 Link encap:Local Loopback …
Red Mad
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php how to determine if ip is localhost?

in PHP how can i determine if an IP address string is a localhost/loopback address or not? my attempt: function isLocalhost(string $ip): bool { if ($ip === "::1") { // IPv6 localhost (technically ::1/128 is the ipv6 loopback range, not…
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Is it technically possible that a packet sent to through the loopback device (127.0.0.1) get lost?

I have a TCP client-server application implemented in C. The client and the server are two separate processes and the communication only happens using sockets which are bound to the loopback device (local address 127.0.0.1). When the communication…
Bemipefe
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What is the meaning of below if condition?

i cannot understand below if condition. if anyone know about it then please help me to understand it. foreach(QNetworkInterface netInterface, QNetworkInterface::allInterfaces()) { if(!(netInterface.flags() & netInterface.IsLoopBack)) { …
coder
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Cannot connect to LocalIP or Localhost (127.0.0.1) Using Arduino ESP8266 or Compatible Boards

I am trying to connect my Arduino ESP8266 or any of the compatible boards like WeMos mini or NodeMCU to my local server, either localhost(127.0.0.1) or 172.xx.xx.xxx port 80. I get an httpResponseCode -1 error. But if I have it connected to a remote…
user7485282
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retransmissions/out-of-order packets with large (~1 MB) writes/reads w/ TCP (SOCK_STREAM) over localhost loopback

I'm seeing retransmissions/out-of-order packets when using the loopback interface and have been googling for days to try to determine if I should be surprised by this (which I am) or if anyone else is seeing it, but I haven't found any…
R.Rex
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JSON model in loopback

I want to return such model from my customer table. { "1521544526409": { "address": "", "city": "", "company": "Atoy oy", "email": "henry.tuohimaa@atoy.fi", "forename": "Henry", "moreinfo": "", "note": "Customer related…
Hardik
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Ratchet PHP: Bind to different port than 127.0.0.1:5555

I have a websocket server written with ratchet and it works well when it is bound to 127.0.0.1:5555. However, i need to run an additional instance of the script on the same machine, so i tried to create another instance bound to a different port,…
JimQ
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What is the difference between the Windows and Linux loopback interface?

I have a WCF service on a Windows 2008 server, that listens on 127.0.0.1:19000, that I am able to connect to externally (i.e. a pc in the same network can ping :9000, and the WCF service will 'hear' the request). I think in linux that I would have…
Zach Smith
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Is it possible to create a registry only on a specific loopback address in Java RMI?

I'm working with Java RMI. Client and server are on the same machine yet. To start the registry on the server, I'm currently using int serverPort = 8081; Registry registry = LocateRegistry.createRegistry(serverPort); So my registry is…
LCP
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Accessing web application using loopback ipaddress from other server is not working

I have a web application which is running on local, the other wants to access my application in local by using http://127.0.0.1:8080/myWeb/checkSession. If other server wants to access my local application i am getting the folowing error. 127.0.0.1…
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Is the loopback (127.0.0.1) a hardware setting?

I've looked through posts with no real answer to this question: is the address 127.0.0.1 a hardware set address much like promiscuous mode is a hardware setting on devices? I've tried to set my address to 127.0.0.1 on eth0, disable the lo, and even…
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Android to PC TCP communication working only on Emulator

I have a requirement to implement an android application to communicate with a c# application on a PC over TCP (wifi). I have followed this - https://workspaces.codeproject.com/dhl_hh/android-how-to-communicate-with-net-application-vi tutorial to…
Hasitha Shan
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Cannot connect to localhost in windows store application

As I read all over the internet: Microsoft blocks the option to listen and receive traffic on localhost (127.0.0.1) for any port. I want for developing purposes to test my 2 server/client apps locally. I followed the instructions here: 2015-08-31,…
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