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Questions tagged [loopback]

Loopback means the interface created and designated to test a local port or interface. It routes test messages from their source device back to the source without any processing or modification. For TCP/IP on an ethernet interface, the loopback IP address is usually 127.0.0.1.

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OS X Audio hiss/dropouts on recorded loopback audio

I've been trying to achieve a desktop audio recording loopback setup like this one https://www.youtube.com/watch?v=AGc42kDiND8. So far, all of my attempts produced audio recordings containing hiss/...
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dummy_hcd loopback webcam. Impossible?

I've been trying to create a loopback USB Webcam device with the help of dummy_hcd kernel module. Steps I've taken: I load libcomposite via modprobe libcomposite. Then I load dummy_hcd via modprobe ...
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iptables repeated entry, what is the logic behind it?

I bumped into these iptables entries for a specific scenario I needed to replicate! iptables -F iptables -P INPUT DROP iptables -P FORWARD DROP iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m ...
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How do I override the automatic address assignments on the loopback device?

Background On modern linux systems the preferred way of managing network interfaces, ip addresses and routes, and related things is tools from the iproute2 package. I am trying to set up a somewhat ...
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Need help to create a loop to copy and paste data in a certain way

I am struggling with a loop from past 3 days, finally requesting help from the community. I want to each cell in column M from (input sheet) to output sheet in column BE multiple times based on the ...
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Excel VBA - Loop to Compare Cells, Offset entire row

Hopefully someone can help me with this! Just started learning VBA. I am trying the following code. The aim is to compare cells in rows starting from row 4 to and offset entire row up or down based on ...
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Cannot detach file-backed loop device after unmounting

I have some image files that I often use for cross-compilation work via chroot. My usual deal is to create a loop device with it, mount its main partition, bind mount /dev, /proc, /sys, and maybe /etc/...
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Create a virtual input device that loops back audio output, if Stereo Mix is unavailable?

I want to use Friture to analyze the audio from my speakers (while working on sound synthesis). I have seen tutorials mentioning Stereo Mix, but as I don't have the Realtek Audio Driver, this is ...
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Vnc viewer error: unable connect to socket: Connection refused (111) in CentOS 8

I would like you to help me with the following problem. I will try to give as many details as possible. I recently installed a vnc server on a Centos8 virtual machine. I have done all the ...
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2 votes
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Pulseaudio loopback into headphones

I have headphones and a mic attached to my computer. My headphones are tight and block out external noise far too well, and so I find myself shouting at the mic. Is there any way of setting up ...
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Why is IPv6 not so heavily using loopback as IPv4 does?

Why is IPv6 not so heavily using loopback as IPv4 does? My OS: Linux Mint 20, kernel version 5.4.0-42. For the purpose of generating the output below, I defined an alias: alias iptables-watch="...
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FFmpeg output sent to v4l2loopback video device won't be read by guvcview

I set a dummy camera /dev/video1 with v4l2loopback module. I can read the stream with ffplay, vlc or even zoom of this camera when I send to it contentwith ffmpeg: ffmpeg -re -i input-file.mp4 -f v4l2 ...
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Take active cells value and copy to another cell. Excel VBA

I am putting together a list to loop through in Excel. I want to loop down column A starting at A2, and copy the value from the active cell to D2 (always D2) This is what I have so far: Sub Test2() ...
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Mounting as loop device fails with "wrong fs type, bad option, bad superblock, ..."

I tried $ mount -o loop ./live-cd.iso /mnt on a Live-OS image, which failed: mount: /mnt: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error....
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Is a /dev/loop preferred for mounting file-as-filesystem?

I have been hacking around with files as filesystems, for things like encrypted volumes and the like. This tutorial uses losetup and a /dev/loopX device to facilitate the mount process. However, ...
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What is the bottleneck of loopback?

Recently I am curious about that question, so I installed iperf3 on my macOS to benchmark my the performance of the loopback on my macOS. However, the CPU usages didn't reach 100%, which is expected ...
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loopback api - persist AccessToken

First and foremost, my setup: Ubuntu Server 18.04 Loopback API 3.X Node version 12.6 My issue: I set up Loopback API and created a few models and users. Now, all I need LoopbackAPI for is really ...
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How create loopback interfaces in Linux permanently

I aim to create 2 loopback interfaces and have them saved permanently in EC2 instance on AWS Linux Ubuntu based. I did the following in /ect/network/interfaces auto lo lo:1 lo:2 iface lo inet ...
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RouterOS Hairpin NAT not working

I am trying to achieve this. https://wiki.mikrotik.com/wiki/Hairpin_NAT WAP IP: static LAN IP: 192.168.1.1 Web Server: 192.168.1.88 I can get to the web server from outside without any problem ...
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Requests to all Localhost Ports through Browser return "connection blocked"

I wanted to open page on localhost that used to work before but this time browser showed only (as html <pre> tag's content) connection blocked Other Apache pages on other ports are not working ...
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I need to create a dummy network adapter with a specific.customizable MAC address

I am trying to put a band aid on a very flawed piece of software, and need to create a dummy network adapter in Windows that will have a MAC address matching one of my real network adapters. This ...
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Working around the Network Loopback Isolation of UWP Apps

I've been hitting a blockage trying to get my UWP App to receive data from a local UDP port in the following scenario: Windows 10 | Version 10.0.16299 Build 16299 UWP target and minimum Version 10.0....
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unexpected network loopback device on linux [duplicate]

executing ifconfig I found network loopback device which was not expected to show (maybe some linux packages created it on it's own?) but I would like to analyze it what it does - any ideas how to ...
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How to create a Loop in Shell Script to do a specific task?

I am trying to clean a Huge database of emails, but when I use the following Grep command, I get "Memory Exhausted" Error. pv "Suppresion-List.txt" | grep -vf <(sed 's/^/^/; s/$/$/' EMAILS.txt) &...
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loop(repeat) script block until successful db(mysql) password

I have the following function function executeMySql() { while IFS= read -p "$prompt" -r -s -n 1 char do if [[ $char == $'\0' ]]; then break fi if [[ $char == $'\177' ]...
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5 votes
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Why is loopback on Windows 10x slower than loopback within a Linux VM?

I have been testing the speed of my windows machine's loopback adapter using iperf3 which has given the following results: However, when I run the exact same test within a linux virtual machine ...
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4 votes
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Enabling NAT loopback on Zyxel C3000Z Modem/Router?

I have a C3000Z router from Century Link and it does not have NAT loopback enabled by default. The option is simply not available on the Web GUI. However browser around I found a few other models of ...
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Make localhost server exempt from UWP app network isolation?

By default, UWP apps cannot access network resources on the same machine. This restriction can be lifted per app using the CheckNetIsolation.exe utility. This is described in many places around the ...
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How to trick a Linux program into "seeing" just the loopback network interface lo0?

The title says it all. I am trying to avoid the situation when a program detects the IP of a network interface and sends it to a remote location. I am thinking to do this by tricking the program into ...
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Monitoring network traffic from Microsoft Loopback Adapter

I am getting my internet connection through a Microsoft Loopback Adapter (coming from a Virtualbox), and because of loopback implementation, you can't monitor its traffic via Perfmon or Task Manager. ...
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2 votes
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1k views

Speed of loopback interface

I am working now with nfs shares. And I want to connect to localhost with nfs. I have disk that can read/write ~400MB/s but when I connect to nfs on localhost I have only ~110MB/s. I read that ...
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Is it possible to connect to the same computer WITHOUT loopback?

I'm trying to measure the speed of the connection between my computer and my router. I'm using iperf for this, but the problem is that entering my own local IP address bypasses the network and ...
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Constant TCP requests and failed responses

I'm getting one of these per second: 457 205.494657 127.0.0.1 127.0.0.1 TCP 68 49507→23454 [SYN] Seq=0 Win=65535 Len=0 MSS=16344 WS=32 TSval=630136859 TSecr=0 SACK_PERM=1 458 205.494702 127.0....
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4 votes
1 answer
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Do we need NIC to ping loopback IP

I read that pinging loopback will work if we have TCP/IP suite installed on our computers and don't necessarily have a NIC. So, do we need NIC to ping loopback ip(127.0.0.0) ? Thanks.
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What is a "loopback", can it cause "damage"?

The high school I attend won't allow students to have the WiFi password. Our entire education system is evolving and becoming more and more dependent on the internet. Therefore, I brought my own ...
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1 answer
3k views

NAT loopback on my router

Tried all for a day still can't get it done. I am trying to configure 'NAT loopback' on my router. Router LAN IP: 192.168.1.254 (br0) Router WAN IP: 192.168.10.129 Web-server LAN IP: 192.168.1.1 ...
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2 votes
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Loopback adapter breaks wifi

When I installed the loopback adapter on Windows 10, the wifi stopped working. Disabling the adapter makes the wifi go back to normal. The wifi adapter stays enabled, but just can't connect to the ...
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1 answer
2k views

Differences between firebase, loopback and redux

I want to develop a web app and later corresponding android/ios apps. So far I have only decided the front end for which I want to use react and react native for mobile. For the rest of the ...
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4 votes
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How do you disable the loopback device windows 10?

I have found this question for Windows 7 many times (example), but this does not work on Windows 10, because I don't think the loopback network adapter is exposed in the same location. At least for ...
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666 views

Folder Redirection Not Working With Loopback Processing

I have an OU named TEST-OU where I want to apply Folder Redirection to all users in that OU. So far this has been working fine. Next I created a sub-OU below that one called TEST-SUBOU where I want ...
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3 votes
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8k views

Make "ping localhost" resolve to "127.0.0.1" instead of "::1" without the -4 option

Context We're wanting to use RawCap to inspect HTTP requests to localhost. RawCap though cannot capture IPv6. We've considered doing a massive find-replace of "localhost" with "127.0.0.1" in our ...
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6 votes
1 answer
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iptables reject tcp-reset on loopback

I am trying to check how a software would behave if there is a network failure. That software is using tcp send() and recv() to communicate. Previously I was making the software communicate by ...
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Centos cURL connection refused on Its own IP

I have two services on one server (with different ports to access them). One of my services is trying to connect to the other one with the IP of server and its specific port. But I got some errors ...
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how to loopback a subdomain with same ip in windows 7

Ok i'm trying to loopback a subdomain of some webserver. There's 3 subdomains in the website. www, static and play. I pinged the static.website.com and i got this ip 123.123.3 (Example only). So i ...
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File-based loop device with writing support and dynamic size

Usually loop device (v-node disk) is based on a file with pre-allocated size (e.g. an image of a floppy drive or ISO disk). The device is then treated as a block device and can be formatted with any ...
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Is proxy traffic monitored by loopback device?

I understand loopback device acts like a mirror interface to my localhost. When I do ifconfig on my Ubuntu machine, I get this lo Link encap:Local Loopback inet addr:127.0.0.1 ...
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2 votes
1 answer
3k views

How to enable NAT Loopback when modem connects to router

I want to see my hosted pages using my public address from inside and outside my network, but so far I can only from outside. The thing is that I recently changed ISP, and they brought me a ZTE-F660. ...
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-1 votes
1 answer
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Website gets redirected to 127.0.0.1 occasionally

I am trying to access AirAsia's Web Check-in Page. Occasionally I can access it. However, most of the time I get redirected to 127.0.0.1. Could this be an ISP issue? Details: My hosts file is clean. ...
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1 answer
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Difference between 127.0.0.1 and 0.0.0.0 in the context of the Firefox address bar

I need to configure a firefox extension to load a page that can never exist. It should be as fast as possible. The obvious choice is about:blank, but the catch is that the API used by the extension ...
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2 votes
3 answers
4k views

Running DNS Server to circumvent NAT-Loopback issue

First I want to say that I probably read everything that there is on the internet regarding the problem. And the problem is that I can not access my owncloud over doc.selfhost.eu if I am in the same ...
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