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Questions tagged [loopback]

In TCP/IP a loopback device is a virtual network interface implemented in software only and not connected to any hardware, but which is fully integrated into the computer system's internal network infrastructure. Any traffic that a computer program sends to the loopback interface is immediately received on the same interface.

In TCP/IP a loopback device is a virtual network interface implemented in software only and not connected to any hardware, but which is fully integrated into the computer system's internal network infrastructure. Any traffic that a computer program sends to the loopback interface is immediately received on the same interface.

A loopback interface has several uses. It may be used by network client software on a computer to communicate with server software on the same computer, namely on a computer running a web server, pointing a web browser to the URLs http://127.0.0.1/ or http://localhost/ will access that computer's own web site. This works without any actual network connection–so it is useful for testing services without exposing them to security risks from remote network access. Likewise, pinging the loopback interface is a basic test of the functionality of the IP stack in the operating system.

Source: wikipedia

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Packetloss in Juniper SRX with gigether-options loopback enabled

I have run into an interesting problem with a Juniper SRX 240 box. The box is running BGP as a border router, and is announcing a /24. To ensure that the vlan with the network stayed "up" I set the gigether-options loopback option on one of the…
pehrs
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Why do HTTP loopback connections not work on my subdomains?

I have a shared hosting account at Jumba running Linux kernel 2.6.9-103.ELsmp (don't know if that helps) with cpanel 1.0 (RC1). I am using the WordPress plugin Backup Buddy, which requires HTTP loopback connections to monitor / complete backups. …
ptim
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Configuring Cisco ASA to access internal websites with different domains

I can access www.foo.com because my AD domain is foo.com and the webserver's name on the domain is www. I want to access www.bar.com and www.bar-foo.us and whatever alter ego my webserver wants (all on same web server). Everything is accessible…
Peter Turner
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Cisco routers "loopback"

I have Cisco RV220W. I have configured with NAT, and its working good from outside. (From WAN) But when I is on LAN-side, and visit my ip-address, for instance http://83.213.21.32:80 I am beeing sent to the router login-page. How can I fix this?…
Aidora
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Avoid write on a mounted loopback device to be propagated

I have a device that mounts its root file system using NFS. On my NFS server I have a file representing the device's file system, namely target.ext2, which I mount on the appropriate /export directory. I would like the device to be able to write on…
Thiago Cardoso
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make local only daemon listening on different interface (using iptables port forwarding)?

i have a daemon program which listens on 127.0.0.1:8000. i need to access it when i connect to my box with vpn. so i want it to listen on the ppp0 interface too. i've tried the "ssh -L" method. it works, but i don't think it's the right way to do…
UniIsland
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Using host loopback device into VMs

While deciding what IP address to assign to a local VM a question arose into my mind: why can't I just assign an address of the 127.0.0.0/8 net (so I can avoid any kind of IP clashing)? After all, it is possible to bind HTTP server/whatever to…
Mega-X
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Stop Nginx from listening on all loopback IPv4 addresses EXCEPT 127.0.0.1

On Ubuntu, Nginx apparently listens on all of the IPs in 127.0.0.0/8. How can I disable listening on 127.0.0.0 and 127.0.0.2–127.255.255.255? That is, the only IPv4 loopback address that I want Nginx to listen on is 127.0.0.1. Answers to this…
Ben Zelnick
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On Linux, how to send packets with local destination NOT through the loopback interface

I have a Linux server with two ethernet interfaces which are connected to the same switch and are in the same subnetwork. The topology is as following +--------------------+ | | | +----------+ +----------+ | …
Donlon
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Postgres processes exceed max_worker_processes?

I have three Docker containers: one running Postgres and two others running LoopbackJS (the actual setup is more complex, but I'm simplifying here for clarity). The Loopback servers read/write to a database in the Postgres container. The host…
gfields
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Can Loopback IP be Public

I have a Usecase where an Access Device need to reach a Core Device over the Internet. Access Device is configured with the Public IP of the Core device as of now so that it can reach the Core over the Internet. Click here for current setup However,…
Alex Philip
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Loopback connection seems blocked

Here is the situation i met: Server is managed by laravel forge It is serving behind cloudflare reverse proxy Nginx is up and running, listening on both port 80 and 443 (confirmed) now i need to configure a custom load balancer for this server,…
0nepeop1e
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Linux: Reserving a loopback port to a user with no authentication. Is this possible?

I want the user who starts the listening process on the port on the loopback interface to be the only user who can connect to this port. Reserving the port. No authentication. I want other users to be able to be able to do the same on any available…
David Diggles
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Windows firewall ipv6 loopback issue

I received it on my windows firewall log: DROP TCP ::1 ::1 53264 47001 I tried to add ipv6 ::1 or any other ipv6 loopback address to the firewall rule but received only the message below: An unspecified, multicast, broadcast and loopback IPv6…
Andro Leo
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What is the difference between the loopback interface and the 127.0.0.1 IP address?

I am trying to allow connections between softwares running on the same machine in iptables. The following kill my internet connectivity: # The following rules doesn't allow the VPN connection to be established #-A INPUT -i lo -o lo -j ACCEPT The…
robertspierre
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