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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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How can I give access to loopback devices which are created dynamically to a Docker container?

I have a small Docker container from which I can access /dev/loop0. For this I've added to docker run: --device=/dev/loop-control:/dev/loop-control \ --device=/dev/loop0:/dev/loop0 \ On this loopback device I'm creating two or more partitions with…
emmerich
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Heavy TCP traffic on loopback

While trying to generate some test traffic on my loopback interface, I noticed there was so much noise there that the output from Wireshark was essentially useless, with tons of SYN/RST, ACK packets on port 4101 (which some Googling suggests has to…
Guilherme
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Is it important to use localhost/127.0.0.1 rather than machine's own IP address?

I'm on Amazon AWS EC2 running Amazon Linux, though that may not be significant to the answer. Say I have three hosts, H1, H2, H3, with private IP addresses of 10.0.0.1, 10.0.0.2, and 10.0.0.3. This could be represented in a /etc/hosts file with…
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Centos 7.1 Create Loopback Interface

I'm trying to alias an ip address onto Lo or create a new loopback interface such as lo:1 I've created…
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Loopback Processing Merge Mode

I am part of a team of IT Engineers who are currently revamping a large organisation. The previous IT department had some Group Policy objects in place for installing software(s), applying security related changes to machines, etc, etc. On some of…
Jake
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Why is the loopback device needed on a client side of Stunnel?

This SANS Institute guide states that "On the client side, a port listening on the loopback interface of the local system would send/receive data on the clear-text protocol and tunnel out on an ephemeral port to connect to the secured port of…
Withheld
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Is there a security downside to having iptables ignore the loopback interface?

I have the following rules in my iptables (I cut out the rules that aren't relevant to this question): *raw :PREROUTING ACCEPT :OUTPUT ACCEPT -A PREROUTING -i lo -j NOTRACK -A OUTPUT -o lo -j NOTRACK COMMIT *filter -A INPUT -i lo -j ACCEPT -A…
Tim Tisdall
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Configuring a loopback interface on a Cisco router

I have Router 1 with the following interfaces: FA0/1: 192.168.9.193 255.255.255.224 S0/0/0: 192.168.9.129 255.255.255.224 S0/0/1: 192.168.9.161 255.255.255.224 This is for my assignment at university, there should be a computer connected to the…
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Monitor loopback traffic (monitor MS TCP Loopback inteface traffic) with Microsoft Network Monitor 3.4 - possible?

I've downloaded NM 3.4 from microsoft.com and it appears that the software doesn't capture traffic on MS TCP Loopback interface. When I ping 127.0.0.1 address, NM shows no packets flowing. I've tried both promiscuous / standard NIC mode with no…
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DRBD on a file (rather than partition)

We have a number of Xen virtual machines that use disk image files. disk = ["file:/xen/vbd/something.vbd,sda1,w"] We'd like to use DRBD to replicate these files for backup (as opposed to the mess of MySQL replication and nightly rsyncs we have at…
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How to setup loopbackon my Windows Server 2008 Virtual PC VM?

I am trying to setup a virtual sharepoint environment for development and need to be able to access my sharepoint sites on my host machine. From hours of google research, I discern that I must setup loopback, but haven't been able to get it to work…
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IP Address is very slow compared to loopback address

I have an AWS EC2 VM. I want to run a bunch of scripts on a PostgreSQL server hosted on the same machine. When I use the IP address of the server in scripts, it took almost 5 seconds per script. But when I use the loopback address instead of server…
YogeshR
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Does Loopback able to support all TCP/IP protocols

Does a Windows loopback adapter supports ACD and duplicate IPs. Say we have a code that supports full TCP stack and we bridge the program to loopback using PCAP. If in case I set both the address same - is it the right way to test ACD? Do we need…
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Corosync cluster will not bind vips to loopback, so apache fails to start in CentOS 7

I have a problem getting apache to work in a corosync cluster. I probably sifted through more than hundred web pages and a couple of dozen Google Searches, and was not able to find any matching answer on my issue. root@hh1web03t ~# uname -a Linux…
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Bandwidth limitations of network loopback device?

I have several JVMs that all listen to TCP 80 each bound on their own 127.0.100.1 -> 127.0.100.255 range. Is there a theoretical limit to the effective bandwidth that can be pushed through the LO device? Is this simply a limitation of the kernel…
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