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 ...

learn more… | top users | synonyms

0
votes
0answers
4 views

Create a write-cache loop device for a much larger block device [migrated]

So, long story short. * I had a 5.5TB RAID5 array with a HP controller. * HP uses a really, really painful RAID5 algorithm (ref: Delayed Parity) * I wrote a new block driver that translates requests ...
-2
votes
0answers
29 views

IP Route Add Issue [migrated]

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. ...
0
votes
0answers
52 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
votes
1answer
28 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
81 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
86 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
30 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
561 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
90 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 ...
1
vote
1answer
758 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
votes
0answers
59 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
2k 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 ...
0
votes
1answer
308 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 ...
2
votes
1answer
852 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
vote
0answers
161 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
141 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 ...
-1
votes
1answer
495 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
446 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 ...
1
vote
1answer
122 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 ...
5
votes
2answers
313 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
114 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
3k 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
995 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
votes
2answers
618 views

Postfix - Mail for domain.com loops back to myself

i know there are a few threads about this already but they don't seem to fix my problem. I've got a Ubuntu Server running Plesk11 with POSTFIX Server as email engine. My primary domain - lets call ...
0
votes
1answer
121 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 ...
2
votes
1answer
728 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 ...
1
vote
1answer
105 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
460 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 ...
2
votes
1answer
524 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 ...
2
votes
1answer
4k 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 ...
0
votes
1answer
984 views

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 ...
6
votes
1answer
449 views

How can I copy a LVM logical volume to a loopback file on another system?

I am trying to copy an LVM logical volume with an ext3 filesystem from one system to a file on another system that I will be able to mount as a loopback device. I have tried the following command to ...
21
votes
3answers
5k views

What is the rest of the 127.0.0.0/8 address space used for?

We all know what 127.0.0.1 is used for (loopback). But is the rest of the reserved 127.0.0.0/8 loopback space widely used for anything?
1
vote
0answers
769 views

ext4 loopback device, Buffer I/O Error on reboot

I am trying to mount a loopback device on my ext4 formatted ssd drive. I get these errors when I reboot on Linux kernel 2.6.38.8 Buffer I/O error on device loop1, logical block 0 Here is what I do: ...
2
votes
3answers
3k views

What is the proper position for the loopback address in a DNS server selection list?

Best practices indicate that one should list 127.0.0.1 in the DNS list for the network adapter configuration for a Domain Controller, but not as the first one. With that said, what is the best place ...
-2
votes
1answer
911 views

How to access server using public ip when in the network itself? [duplicate]

I've asked this question and even searched around but didn't get a useful answer for me. Basically what im doing is i have a webserver on internal ip 192.168.0.100 port 80. So if im in the network it ...
1
vote
0answers
1k views

network-mapped file system drops to read-only mid-stream, buffer I/O error with device mapper

Under linux 2.6 (CentOS 5.3 actually), I have a file system that works okay for a few minutes, then drops to read-only mode, while I am trying to read/write data to it. It is an ext3 file system ...
2
votes
3answers
5k views

Curl request wont resolve to localhost

I have an ubuntu server running apache on localhost / port 80. It's domain is sub.domain.com If I make a curl request to http://localhost on that machine it will error with 'couldnt connect to host' ...
2
votes
2answers
946 views

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 ...
0
votes
1answer
1k views

iptables DNAT from loopback

I'm trying to understand the limitations of using iptables DNAT with loopback addresses. Consider we have an application which can connect only to 127.0.0.1; the obvious solution to make server and ...
85
votes
2answers
32k views

Why does my hostname appear with the address 127.0.1.1 rather than 127.0.0.1 in /etc/hosts?

This may be a bit of a noobish question, but I was taking a look at /etc/hosts on my new Xubuntu install and saw this: 127.0.0.1 localhost 127.0.1.1 myhostname On most 'nixes I've used, the second ...
4
votes
3answers
1k views

Loopback interface on Linux catches all loopback traffic

On a linux machine with a normal loopback interface: $ ifconfig lo lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host ...
4
votes
1answer
2k views

What is the Microsoft Loopback Adapter used for?

Why is Microsoft Loopback interface called _loopback_ inteface? RFC3330 states that a loopback interface is an interface with an IP address in the 127.0.0.0/8 address range. Yet, when I enter the ...
2
votes
2answers
3k views

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 ...
2
votes
1answer
634 views

Boot Linux from a disk image on a Windows partition

I'd like to install Fedora 15 to a disk image on a Windows 7 partition, then boot from that image using the Windows 7 native boot loader. The advantage of this would be to avoid resizing the NTFS ...
0
votes
1answer
393 views

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 ...
0
votes
1answer
245 views

Why can I fetch from web server via loopback but not IP?

I have a web server (Thin) running on a non-standard port on my Ubuntu 10.04 Server box. I can access the web server via the loopback interface, but not the public IP. Why, and how do I fix the ...
7
votes
4answers
2k views

Why can't I ping an address on the loopback device under FreeBSD?

From Wikipedia: The most commonly used IP address on the loopback device is 127.0.0.1 for IPv4, although any address in the range 127.0.0.0 to 127.255.255.255 is mapped to it. This is not ...
2
votes
1answer
638 views

HP switch 'mirror port' makes a Cisco switch port err-disabled due to keepalive loop-back

I'm trying to connect an HP ProCurve 5304xl switch to a Cisco 2950. The HP port I'm connecting to is described as a 'mirror port', which appears to be like a SPAN port except that it also allows ...
1
vote
2answers
3k views

Disable ipv6 loopback

I am trying to get the IPv6 loopback completely disabled/disconnected. Searching the posts here I see everything that I have done so far. 1)Un-check the IPv6 on the adapter which will disable IPv6 ...