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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Why do I need a loopback adapter on the target hosts of a Virtual IP?

I recently ran into a problem involving virtual IPs for the first time. The virtual IP targets two different (as far as I can tell, physical) hosts. The hosts are linux, but I don't know what software ...
3
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3answers
38 views

Why does Linux accept traffic on unconfigured loopback addresses?

On at least two version of Linux (Ubuntu 9 and Debian 7) I've noticed that, even though I only have a single loopback address configured on lo (the standard 127.0.0.1 one), it happily accepts packets ...
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20 views

Does connecting to one's computer via local router automatically uses the loopback?

I have a TCP application that doesn't show up on Wireshark. I read it was because Wireshark is not able to sniff Loopback communication on Windows. So, instead of connecting to 127.0.0.1, I connected ...
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1answer
51 views

How to reroute external IP address to localhost?

I have a software that I no longer have access to it's source code that is connecting to a server on a certain IP. I want to be able to mimic the same server's functionality and route the IP address ...
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23 views

Is there an alternative loopback method?

Are there any other alternative loopback methods than these? Microsoft Loopback Adapater netsh int ip add addr 1 [ip] - this method Is there another method to loopback a certain IP?
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21 views

Alternative loopback method

I'm trying to loopback a certain IP from a certain game (not hacking). The game has blocked the following methods so I need to find another method to loopback the game's IP to localhost. Microsoft ...
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2answers
128 views

How can I use curl with ::1 for ipv6 based loopback?

I tried a few ways but they seem to be confusing curl. root@testt:~# curl localhost:8080 <h1>Hello world!</h1> <p>Boom Bam Splat</p> root@testt:~# curl ::1:8080 curl: (3) ...
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1answer
31 views

Is there any benefit in activating NAT loopback for basic video gaming? Does it help a PS4 use UPnP?

I have a router that I can turn on and off NAT loopback. The router is just used for game playing and phones and normal everyday Internet browsing. My question is this will there be any benefit to ...
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55 views

LAN access to home server using dnsmasq

I set up an OwnCloud server on a Raspberry Pi. To access it easily, I used a dynamic dns solution which points to my public IP. Every port is open and it works just fine when I access the server ...
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23 views

Loopback packet from FTTH modem for every 2 seconds

To investigate some network problem, I had installed WireShark. I could see "broadcast LOOP unknown function" packets are constantly coming. The packet is like this. FF FF FF FF FF FF (6 bytes, ...
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51 views

Force local packet pass trough the router (or disable loopback) - windows 8

i would like to avoid that packets sent from my machine to the same machine (via the IP assigned by the external router eg. 192.168.1.20) are routed with loopback and so never reach the external ...
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1answer
289 views

How to test whether a router supports NAT loopback?

I've been unable to find much information on whether my router (Linksys EA4500) supports NAT loopback, so I'd like to perform a test to tell me whether accessing my external ip address from within the ...
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93 views

How can I add loopback adapters with the command line and configure them with the command line?

What is the command line to add a loopback adapter with IP 127.0.0.2 on Windows 8.1? I need to add 65,000 ip's to my local machine for network stress tests (connections from many different IP's) for ...
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2answers
112 views

IP Route Add Issue

I'm trying to set up IE browsing with fixed routes in the route table. Before adding the static route, I can browse http://www.whatsmyip.org/ with internet explorer After I add a fixed route e.g. ...
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109 views

How can I create Local Loopback on Linux (RedHat or Debian)?

How can I do the same on Linux (RedHat or Debian)? I need to create local loopback as shown herein: ...
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0answers
123 views

Block any connection in the Microsoft Loopback Adapter with Windows Firewall

What (inbound?) rule should one add in order to block any connection running inside the Microsoft Loopback Adapter? Is that even possible? I heard that almost for the default loopback (127.0.0.1) any ...
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1answer
424 views

How to delete loopback adaptor in Windows 7 using batch script?

I have created 10 loopback adaptors on Windows 7 using devcon devcon -r install %WINDIR%\Inf\Netloop.inf *MSLOOP I put this in for loop and every thing is ok but now I want to delete them using ...
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1answer
167 views

How to change interface loopback adapter address in Windows?

Hi I created new loopback adapter in Windows 7 using: devcon.exe install %windir%\inf\netloop.inf *msloop Then if I execute ipconifg Ethernet adapter Local Area Connection 4: ...
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19 views

How to map only a part (byte- or block-based) of a device file or regular file to a loop device?

How can I create a loop device of an existing block device or regular file of size z so that a certain byte x (with x > 0) appears as first byte, x+1 as second, etc. and a certain byte y as last ...
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1answer
33 views

Kernel-level pass-through method to change file hashes

I'm searching for any kernel-level mechanism that is pass-through and will change file hashes by either encrypting file contents or appending data. The most obvious solution is encryption, but I can't ...
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0answers
56 views

Make ejectable fake block device in linux

I have a testing setup using loop devices to stand in for some external devices (these are basically a replacement for tape storage - removable disk cartridges formatted as NTFS). This works pretty ...
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1answer
182 views

Permanent loop device?

Are loop devices on Linux that are created with losetup supposed to be permanent? This does not seem to be the case for me. Whenever I restart my computer I see that the loop device is gone. I am ...
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0answers
73 views

Why isn't the loop back interface replying to injected ICMP echo request?

I want to be able to send IP packets from a userspace program and receive responses on a TUN interface. To test, I'm injecting ICMP icho requests to the loopback interface from a user space ...
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2answers
249 views

Tshark is displaying “florence” and “eforward” rather than source/destination port numbers

I am running rawcap on windows7 loopback adapter. I have run telnet localhost 2181 15 Packets were generated. In order to view the output I ran wireshark\tshark -r \shared\pcap.pcap And here ...
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1answer
243 views

How to make two loopback adapters talk each other?

I have to test some java network application. Each client-app is identified by his IP. So the simpliest way to test it is to run some machines or VMs... But each instance of this application can be ...
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2answers
762 views

Create Loopback and assign local addresses on Windows 8

I'm usually on OSX where I often add additional IP addresses to lo0 interface to simplify ssh tunnelling to various services on different machines to different local addresses: # Tunnel mysql ...
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157 views

IPSec Policy Is Blocking 127.0.0.1

I created an IPSec policy on Windows 8.1, it's purpose was to allow only traffic that goes via the VPN, everything else should be blocked (except LAN and 127.0.0.1). LAN is working fine, but 127.0.0.1 ...
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95 views

Loopback Address on OS-X

Wikipedia has this to say about the loopback address Various IETF standards reserve the IPv4 address block 127/8 (from which 127.0.0.1 is most commonly used), the IPv6 address ::1, and the name ...
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1answer
66 views

How to make Linux read DOS partition table and create partition devices from loopback?

# blockdev --rereadpt /dev/loop3 BLKRRPART: Invalid argument How to make a "virtual HDD" in linux. It should be like loopback, but also with with automatic linux's detection of partitions and udev ...
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203 views

Direct traffic from LAN interface into VPN

I have created a loopback network interface (by a software tool). Now I want to direct internet traffic through this interface. Note that I only can access internet via a VPN . Now I do not know how I ...
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1answer
694 views

Cannot format local loopback filesystem

I'm trying to make a 40GB ext3 local loopback file system. This loopback filesystem is stored on my NAS which is mounted on a Ubuntu Precise 12.04 x64 machine using NFS. The machine has both read and ...
2
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1answer
439 views

Why TCPReplay show warning when packets replayed on loopback interface?

When I use following command to replay 1.pcap over lo: tcpreplay --mbps=10 --intf1=lo 1.pcap Then I see these warning: .Warning: Unsupported physical layer type 0x0304 on lo. Maybe it works, ...
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139 views

How do I send data to the Microsoft Loopback Adapter?

I have a Microsoft Loopback Adapter installed and I have a program that listens to data on this adapter. But how exactly do I send data to this loopback adapter in Windows? There must be some tool ...
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1answer
35 views

losetup Find in Parallel / Concurrency

I'm writing a makefile that at some point builds image files. I'm using losetup -f in the file to find a free loop device when building out each image. Since the images are independent of each ...
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0answers
440 views

loopback adapter lost ip address 127.0.0.1?

I noticed networking issues and discovered lo was not behaving properly: it did not have any ip address! lo Link encap:Local Loopback LOOPBACK MTU:16436 Metric:1 RX ...
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1answer
380 views

Magento Localhost Installation - LAN Works - WAN Issues?

I’m new to home servers and Magento. Running Ubuntu Server 13.04 with LAMP and Magento Commerce 1.7.0.2 on a dedicated home server. I've already configured my server's static IP, router's firewall and ...
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0answers
33 views

Can anyone explain how the loopback interface works? [duplicate]

I got to understand how TUN/TAP works from the following illustration: TUN/TAP illustration I'm at a loss how the loopback interface works. Can anyone explain a bit about how the loopback interface ...
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1answer
137 views

trouble shooting the connection between systems by using telnet?

I have a windowsystem called "A" and Linux system called"B" .Our application software is client -server software. So in this scenario server part of application is resding in a window system and ...
7
votes
3answers
6k views

What's the difference between 127.0.0.1 and 127.0.0.0

I know that both are loopback IPs, but they have another ip mask. What's the difference between them? Can they be used interchangeably? ...
2
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4answers
376 views

The opposite of mount -o loop: can I read a block device as a regular file?

I'm trying to back up an LVM volume using Duplicity (note: not just the file contents of the volume, but the actual volume itself, byte-for-byte). The best way I've so far found is to dd all the data ...
3
votes
1answer
5k views

How do you create and partition a raw disk image?

I need to create a raw disk image for use in a virtual machine, but I need to create the partitions before creating the file system or installing the operating system. Can anyone describe a process ...
2
votes
1answer
216 views

Why does Firefox need a loopback connection?

I was playing around with firewalls and iptables. When I blocked any traffic except HTTP and DNS I was able to establish a connection to google.com via wget google.com. But I wasn't able to open ...
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1answer
266 views

Why do DNS queries use loopback interface?

Sniffing (using Wireshark), for didactical purpose, my loopback interface on Ubuntu 12.04, I noticed that a lot of DNS queries (maybe ALL of them) have 127.0.0.1 as source and destination address. ...
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2answers
792 views

TCP/UDP hole punching from and to the same NAT network

I was wondering if tcp/udp hole punching would still work when you are in the same network (behind a NAT), and what the packet's path would be. What happens when using hole punching on the same ...
17
votes
2answers
6k views

How do you get loopback addresses other than 127.0.0.1 to work on OS X

According to everything I read, the entire 127.x.x.x subnet should loopback. However, on my Mac, I can only ping 127.0.0.1 I know I've done this before (though possibly on another OS) and has come ...
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3answers
3k views

enabling loopback NAT

I have a Qwest Aciontec Q1000 modem/router combo, which does not support loopback. I run a webserver on the LAN, and when I'm on the LAN, I can only access it by its local IP 192.168.0.201. When I'm ...
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1answer
561 views

Ubuntu NFS 4: How to avoid the clientaddr param being added?

I'm trying to mount distant NFS. This is what I have in /etc/fstab : server.com:/mnt/hdd /mnt/hdd nfs rw,tcp 0 0 But this param gets added to the mount.nfs args: clientaddr=192.168.x.x Since ...
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1answer
6k views

Windows 7 - Why is the Network on my Loopback Adapter Showing as Unidentified and thus Public?

I'm running a virtual machine (Win XP, but OS doesn't really matter) on my Windows 7 PC using the loopback adapter to create a private network between my host computer and the virtual machine. ...
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1answer
269 views

How far a loopback packet sent from an application layer goes on TCP/P layers?

Assuming that I want to check if my ethernet card is working fine, if I send a ping from a cmd on Windows, how far the sent packet will go? I mean, the packet will fall down over all the TCP/IP layers ...
3
votes
1answer
3k views

How do I reach the host loopback 127.0.0.1 from a VMplayer

I am using VM Player 4.0.2 running Ubuntu 11.10 guest OS on WinXP host, with NAT network connection configuration. I have an application running on Win XP that communicates with a device manager ...