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 ...

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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 ...
1
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1answer
27 views

Ubuntu rename loopback interface

I have a Linux box with Ubuntu 16.04. I've noticed some odd behavior when I needed use the loopback interface. So I checked with ifconfig first and it showed that: rename1 Link encap:Local ...
2
votes
1answer
48 views

Can't access server on loopback address, only on private address

I am running a rails web app server bound to 0.0.0.0 on port 80 like so: sudo rails s --port=80 --bind=0.0.0.0 I can access it at my private address http://192.168.0.13/, normally I can access at ...
0
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0answers
121 views

Why and How to set Public IP on Loopback Interface

I been using this forums for many years and this is the first time im in need to open a question, i search across the internet but i could not get an specific and clear answer, probaly because i dont ...
1
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0answers
69 views

How to create image file and mount via. loopback (Ubuntu to remote backup space)

I've been fiddling around with the Hetzner Backup Space and I want to use rsync via. rsnapshot in order to back up my files (more info at their Wiki here) They state in their documentation: The ...
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0answers
45 views

Slow “ifconfig lo”

How can I diagnose a slow loopback interface? Here is what I see on my Fedora23 box: $ time ifconfig lo lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 ...
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votes
1answer
88 views

How to add IPv6 /64 block to lo (local) interface permanently

I'm using this command line to add /64block IP range to lo network interface. ip route add local 2001:bc8:1234:abcd::/64 dev lo But, when I'm reboot my server. It requires again to execute that ...
0
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1answer
194 views

Server send TCP ACK with wrong number after receiving SYN

I have a client establish new TCP connection then sends request to a server per second. Both client and server are on the same linux box (via loopback interface). The client periodically reports ...
0
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0answers
66 views

Two loopback adapters communication in windows 7 or 8

Once our development systems are upgraded from windows XP to windows 7, my debug setup has stopped working. Steps followed in original setup (Windows XP): Add two loopback adapters Assign ipv4 172....
0
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1answer
706 views

Centos 7.1 Create Loopback Interface [duplicate]

I'm trying to alias an ip address onto Lo or create a new loopback interface such as lo:1 I've created /etc/sysconfig/network-scripts/ifcfg-lo:10 DEVICE=lo:10 IPADDR=192.168.10.1 NETMASK=255.255.255....
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3answers
132 views

Why only a single loopback address on IPv6?

IPv4 allocates a whole block of IPv4 loopback addresses, 127.0.0.0/8. IPv6, in contrast, only allocates a single loopback address, ::1. This seems surprising that IPv6 would be so stingy in its ...
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0answers
25 views

Network Traffic fluctuating, even with loopback

I am using iperf tool to benchmark my network interfaces on two identical machines (Dell Blade Server M620). Both have given different results. On 1st machine, I ran server and clients as: Server =...
0
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0answers
68 views

Colasoft Packet Player with Loopback-Adapter - Cannot recieve UDP-Packages

I have some problems with Colasoft Packet Player. I am trying to send the UDP-Packages over a Loopback-Adapter (Windows 7, I want to send and receive them over the same computer) and to read them with ...
3
votes
1answer
174 views

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 ...
0
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0answers
41 views

Reconnectiong to a loopback PSSession from another computer

On the server , open powershell and type New-PSSession -ComputerName localhost A new PSSession is created in the local computer, Get-PSSession returns the session information correctly. Now go to ...
3
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0answers
73 views

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 ...
0
votes
1answer
46 views

Why does 0.0.0.0 resolve to the loopback device?

Why does 0.0.0.0 resolve to the loopback device? $ curl --verbose 0.0.0.0 * Rebuilt URL to: 0.0.0.0/ * Hostname was NOT found in DNS cache * Trying 0.0.0.0... * Connected to 0.0.0.0 (127.0.0.1) ...
0
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2answers
107 views

Terminal Server and loopback address usage

Been trying to research this question to no avail yet!. Perhaps somebody can help. I am trying to identify if localhost on a TS works in the same way as a straight server. If I have an application ...
2
votes
2answers
210 views

Adding a virtual NIC to a 2008R2 server makes internet unreachable, why?

I currently have a Windows Server 2008R2 box with a single physical NIC. For what I want to do I need two network adaptors in the box. To accomplish this, I added a legacy hardware device "Network ...
4
votes
1answer
527 views

Forwarding a port on the loopback interface to a remote IP/port

I have two Docker containers that I'm trying to network together in a specific way. Container A is running a Redis server on port 6379. Container B is running an interactive shell and needs to access ...
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0answers
269 views

How to create another loopback interface on linux?

And NO: i don't ask about virtual IP. I need 2 different devices lo1 and lo2 to define different mtu and qdisc on them. Thanks.
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1answer
155 views

Is there a Universal/Generic Default Gateway Address in IPv4? [closed]

Is there a universal and/or generic default gateway address in IPv4? I'm looking for something similar to the way you can always reference a NICs IP address from itself with 127.0.0.1 regardless of ...
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2answers
242 views

how to force linux to accept packet with loopback ip

i have an embedded system with an Ethernet interface that needs to accept external packets with IP of 127.x.x.xx. is there a way to force Linux to accept external packets with this loop back address ...
0
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0answers
158 views

2 Webapps hosted on same server talking to each other - do they use eth1 or lo1?

I am trying to establish bandwidth needs for a set of webapps in the company. I am using SNMP to monitor the bandwidth on the eth1 interface, however I am trying to establish what is going over the ...
0
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1answer
180 views

My lo interface is down on boot. What can I do?

My lo interface is down when the system boot. I can turn it up with ifconfig up lo but I wonder what could be the cause? Where can I look to debug such problem?
0
votes
1answer
172 views

Is it possible to limit output bandwidth between eth0 and lo?

I'm trying to limit the bandwidth between my eth0 output (nginx proxy) to my loopback inteface (apache) by filtering on destination port. Incoming Packet -> Eth0 -> 0.0.0.0:80 Nginx -> tc ...
0
votes
1answer
315 views

server listening on loopback IP

I have a barracuda load balancer and a VIP which in turn forwards to a cluster of servers. Each of these servers has the VIP added to the loopback interface as the load balancer is on direct server ...
1
vote
1answer
51 views

Use of loopback Interface in iBGP

As I understand that the loopback interface(127.0.0.1) is used to route packets back to the source. How is it then used to talk to iBGP neighbors? I understand that the goal is to ensure that the ...
0
votes
1answer
2k views

How accessing a NATed, virtualized (LXC) server over public IP from client itself on a bridged network?

Setup ____________________________ ____________________________ | Host | | Client | | Public IP: 66.66.66.66 | ...
0
votes
1answer
198 views

How can node.js bind to loopback IPs that don't exist?

Simple node server started like so: server.listen(8080, '127.0.0.10'); This ip address does not exist anywhere in ifconfig: sudo ifconfig | grep 127.0.0.10 # No matches I can connect to 127.0.0....
1
vote
1answer
2k views

Unable to ping 127.0.0.1 … except as local Administrator

I'm having this issue with two Server 2008 R2 domain member servers built as VMWare guests. The DCs built at the same time do not have this issue. When I try to ping 127.0.0.1 (or "localhost") when ...
0
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0answers
74 views

MSTP with looped port

I have a configuration with two switches connected via a single Ethernet port. A second port of the first switch is looped back (Tx connected to Rx). They have 10 MSTI configured on VLAN from 100 to ...
5
votes
1answer
4k views

How do you NAT Hairpin in IOS 8.3+

As I asked here and duplicated here it appears NAT Hairpinning is the answer I'm looking for to allow internal servers to loopback through the ASA to access external IP's (without using DNS Doctoring)....
0
votes
1answer
640 views

is it possible to use ms loop back adapter to setup local vlan

Is it possible to use Microsoft Loop back adapter to set up Lan connection between two computer which is logically isolated from the main network? 1st computer: has a regular ip stack 192.168.1.x 255....
2
votes
1answer
2k views

Server hangs at “Shutting down loopback interface” on reboot

I'm having some trouble understanding what's going on with connecting one of our Xen hypervisors to our iSCSI SAN. Ever since we mounted our iSCSI targets, we've experienced hanging on reboots. This ...
1
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0answers
261 views

Capturing on loopback device on Ubuntu LTS: 15 Mbit of traffic and “x dropped packets”

I am trying to capture about 15 Mbit of traffic on the loopback device on Ubuntu LTS using tcpdump, and I am seeing dropped packets. The CPU is a freaking i7, and i have yet to see CPU usage go above ...
1
vote
1answer
457 views

GPO defining a user policy is being applied, despite being linked to a computer OU (without loopback processing)

I must be missing something obvious here. We have a GPO linked to a computer OU. The GPO runs a VB logon script (a user policy) when users log on. I was just about to enable loopback processing on ...
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votes
1answer
885 views

The file system /dev/loop0, has reached critical status because it is 100% full

The file system /dev/loop0, which is mounted at /tmp, has reached critical status because it is 100% full. The problem is when I checked the space of hard disk I found that: /dev/loop0 space:485M ...
0
votes
1answer
913 views

Windows 2008R2 dns loopback best practices, setup correctly but same error [duplicate]

Windows Server 2008, I have setup my newest dns servers dns but it's still giving me an error stating that I don't have a loopback! This server is 192.168.1.9 primary 192.168.1.10 seconday 192.168.1....
1
vote
1answer
194 views

Loopback Processing Behavior - XP vs. Win7

Does Windows XP treat loopback processing differently than Windows 7? I have 4 various screen saver timeout GPOs (1 hour, 4 hour, disable, etc.) and they are set up the same way the answer in this ...
7
votes
2answers
813 views

Concatenating files to a virtual file on Linux

On a Linux system, is there any way to concatenate a series of files into one exposed file for reading and writing while not actually taking up another N bytes of disk space? I was hoping for ...
0
votes
2answers
196 views

Which one is better to query from - loopback-ip or interface-ip?

I have memcache server listing on 0.0.0.0:11211. I have to query the memcached server from the same box. Which one do you think is better: querying from 127.0.0.1:11211 or from interface-ip:11211. ...
0
votes
1answer
7k views

Can you ping a Cisco Router's Loopback Interface from a PC using PacketTracer

I may be misunderstanding what you can do with a Router's loopback interface. I am trying to ping it from a PC on the same network. I am using Packet Tracer to simulate this, a Cisco 1841 and a PC ...
1
vote
2answers
2k views

route packets through hardware loopback interface, not lo

My embedded Linux board has 3 interfaces: eth0 - For all outbound traffic eth1 - A hardware loopback (traffic leaves board, but comes immediately back in the same port) lo - Standard loopback ...
0
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1answer
215 views

Routing traffic externally instead of internal loop

I have one Ubuntu box with 2 network cards. I am running netperf on the computer to measure performance of networking equipment, ethernet coming out of eth0 into the switch then back out into the ...
5
votes
2answers
2k views

No network loopback device after security update ubuntu 12.04

I've had Ubuntu 12.04 on a server for the last several months, with everything working fine. Last night I did an aptitude update && aptitude safe-upgrade to bring in all the latest security ...
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1answer
141 views

Is it okay to copy an image file which is still mounted via a loop device?

I have a 100 GB image file which is created using dd. This image file is mounted via a loop device as read-write. I want to store a backup of this image file at a remote location. I have a script ...
0
votes
1answer
756 views

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 ...
3
votes
1answer
747 views

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 ...
3
votes
2answers
9k views

How to enable HTTP loopback connections?

I running CentOS release 5.8 (Final) for my WordPress blog (www.deluxeblogtips.com). I have a backup plugin BackupBuddy, and it says: HTTP Loopback Connections are not enabled on this server ...