I am following a networking course from udacity.   In one of the tutorials, the professor says that loopback address is almost always 127.0.0.1  So, it means it can be other than 127.0.0.1.  Can it be changed ? If yes, how ?  And also, at one moment, a machine can have only 1 loopback address, is it right ?
121804
I want to add two more loopback interfaces.  I used the following command:  ifconfig lo: 127.0.0.2 netmask 255.0.0.0 up   and type in ifconfig, i can see the loopback address was added.  But if i want to add one more interface... (for example 127.0.0.3) the previous interface (127.0.0.2) was overwritten.  Also when i look in /etc/network/interfaces i see no entry.  How can i add multiple loopback interfaces permanently?
66517
I want to block my server talking to an external IP address continously.  The IP address in question is I think is being hijacked or spoofed. When Used who.is it resolves to Netherlands. But if you use any other tools it resolves to Jordan.  Any step by step configuration is highly appreciated.  Thank you Kind Regards N
66598
I want to map the IP address 192.168.1.222 to 127.0.0.1 so that if I use 192.168.1.222 in the web browser or ping command I get the response (and that from my 127.0.0.1).   Is this possible via routing tables or do I have to add some sort of virtual network adapter?   I try to deal with this problem on a Windows 7 machine and have no other options than a Windows XP maybe.  I'm stuck right there.
90269
I realized that the hostname had changed while I was doing some work using terminal in OS X Yosemite. I thought there might be an IP address conflict so I reset it. However I still get another device's name (someone else's iPhone, to be exact) when I use the hostname command:  Last login: Fri May  1 15:52:42 on ttys000 SomeonesiPhone:~ irem$  SomeonesiPhone:~ irem$ hostname SomeonesiPhone.wireless.duke.local   What's going on and how can I fix this?  It appears the IP address has not changed. But the address that I get by doing ipconfig getifaddr en0 is different from my public IP address.  I looked up my public IP address using Google, like this:
82670
I did the following:  ufw default deny outgoing, sudo ufw allow out 80 which I thought would let me use the Internet but didn't can y'all help?  Also are there any other ports used by Ubuntu for which I should allow outgoing traffic for? I hear these 20, 21, 53, 123, 443 are some what do you all think?  Thanks
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My web server (Ubuntu, Nginx) have both IPv4 and IPv6 addresses assigned by the host. For my website, shall I bind it to only an IPv6 address? Is it the standard recommended way? Or, shall I use both IPv4 and IPv6 addresses?
54905
I have a security system and the network setting only allows a three-digit IP address. I can't set it to 192.168.2.100, instead I have to use 192.168.002.100.  Are these two IP addresses different? Do I need to set my router's LAN to be all 192.168.xxx.xxx in order for this to work correctly? I can't find any solid information about this.
23602
Sometimes I run   hostname -I   on my machine and got only one local IP returned like 192.168.0.10, but lately, there is occasions where I type it and got in return both 192.168.0.10 192.168.122.1.   If I go to my router page and to traffic settings, I don't see this second IP connected to it. How can I go further to investigate what is exactly this other IP, if its related to some other program or even to a security problem?
96307
My IP xxx.xxx.xxx.xx is pointing to example.com at GoDaddy but I just noticed that when I type the IP in browser, it doesn't redirect to the website, how can do this? I am sure this will happen through httpd.conf but unsure about what I need to add.
61561
I have a network containing 20 clients. I assigned IP range 10.0.0.1 to 10.0.0.20 to them. When I do an IP scanning I see someone using 10.0.0.131 in VMware. How can I find out which IP is this IP bridged with? i.e How can I find out which system has 2 IP? (i.e the other IP of this system)  Update:  My system IP in the network is 10.0.0.81:    Output of the IP scanner show someone using 10.0.0.131 in VMware:    And the result of tracert command show nothing between us:  C:\Users&gt;tracert -j 10.0.0.131 10.0.0.81  Tracing route to ghasemi3.it.com [10.0.0.81] over a maximum of 30 hops:    1    &lt;1 ms    &lt;1 ms    &lt;1 ms  ghasemi3.it.com [10.0.0.81]  Trace complete. C:\Users&gt;
63688
So I have two IP addresses - one is on my network settings and is 192.168.0.X. Another one - I checked this address online - is 108.X.X.X. What's the difference between these two IP addresses? Does it have something to do with local vs internet IP addresses? Can someone please explain these two concepts?
28808
My /etc/hosts file looks like this:  127.0.0.1       localhost 10.20.7.67      testsitealpha.dev othersite.dev   testsitebeta.dev   The first two work. The last one doesn't. Why not? How do I make it work? The reason I am doing this, is because I have a test server (othersite.com), which is on the local network, but it's ip can vary. e.g. 10.20.7.98 one day, 10.20.7.35 another, etc.  So, how do I make my system always resolve testsitebeta.dev to the same ip as othersite.dev?
59767
I am setting up a new server with 18.04 based on instructions written for 14.04. I have got as far as these steps:  /sbin/iptables -A FORWARD -p tcp --destination-port 80 -j ACCEPT /sbin/iptables -t nat -A PREROUTING -j REDIRECT -p tcp --destination-port 80 --to-ports 8080 /sbin/iptables-save # To save permanently (reset-persistent): sudo sh -c "iptables-save &gt; /etc/iptables.rules" # Modify in /etc/network/interfaces # Add this line:     pre-up iptables-restore &lt; /etc/iptables.rules     # As below:  # The loopback network interface auto lo iface lo inet loopback     pre-up iptables-restore &lt; /etc/iptables.rules  # The primary network interface auto eth0 eth1 iface eth0 inet static         address XXX.XXX.XX.XXX         netmask 255.255.255.0         gateway XXX.XXX.XX.1         dns-nameservers 8.8.4.4 8.8.8.8 XXX.XXX.0.3 iface eth1 inet static         address XX.XXX.67.47         netmask 255.255.0.0   But it turns out that 18.04 does things a different way, using something called netplan.   I have found questions and answers related to how to revert back to how things were done in 14.04, but I am wondering whether it is better to do the same thing the new way.   How can I do what is being done the old way using netplan?
118438
I am developing a wizard for a machine that is to be used as a backup of other machines.  When it replaces an existing machine, it needs to set its IP address, DNS, WINS, and host name to match the machine being replaced.  Is there a library in .net (C#) which allows me to do this programatically?  There are multiple NICs, each which need to be set individually.  EDIT  Thank you  for your example.  It got me moving on the right track and the quick reply was awesome.  Thanks .  Your code is perfect.  I was in a rush and had already adapted the example TimothyP linked to, but I would have loved to have had your code sooner.  I've also developed a routine using similar techniques for changing the computer name.  I'll post it in the future so subscribe to this questions  if you want to be informed of the update.  I may get it up later today or on Monday after a bit of cleanup.
12303
I would like to use two different static IP addresses for the same network with the same Wi-Fi dongle. I read in different forums that it's better to use /etc/network/interfaces instead of dhcpcd.conf for that purpose. So I changed the /etc/network/interfaces that way:  auto lo iface lo inet loopback  iface eth0 inet dhcp auto wlan0 allow-hotplug wlan0 iface wlan0 inet static     address 192.168.0.60     netmask 255.255.255.0     gateway 192.168.0.10     wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf auto wlan0:0 allow-hotplug wlan0:0 iface wlan0:0 inet static     address 192.168.0.61     netmask 255.255.255.0     wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf   The issue now is that for the most of the time I can't ping any member of the network. During the first 10 seconds, everything works fine and then I mostly don't get any connection.  ifconfig shows the following:  lo        Link encap:Lokale Schleife             inet Adresse:127.0.0.1  Maske:255.0.0.0           inet6-Adresse: ::1/128 Gültigkeitsbereich:Maschine           UP LOOPBACK RUNNING  MTU:65536  Metrik:1           RX packets:1237 errors:0 dropped:0 overruns:0 frame:0           TX packets:1237 errors:0 dropped:0 overruns:0 carrier:0           Kollisionen:0 Sendewarteschlangenlänge:1            RX bytes:100748 (98.3 KiB)  TX bytes:100748 (98.3 KiB)  wlan0     Link encap:Ethernet  Hardware Adresse b8:27:eb:a2:4b:72             inet Adresse:192.168.0.60  Bcast:192.168.0.255  Maske:255.255.255.0           inet6-Adresse: fe80::ba27:ebff:fea2:4b72/64 Gültigkeitsbereich:Verbindung           UP BROADCAST MULTICAST  MTU:1500  Metrik:1           RX packets:15498 errors:0 dropped:10634 overruns:0 frame:0           TX packets:5446 errors:0 dropped:0 overruns:0 carrier:0           Kollisionen:0 Sendewarteschlangenlänge:1000            RX bytes:5910381 (5.6 MiB)  TX bytes:722284 (705.3 KiB)  wlan0:0   Link encap:Ethernet  Hardware Adresse b8:27:eb:a2:4b:72             inet Adresse:192.168.0.61  Bcast:192.168.0.255  Maske:255.255.255.0           UP BROADCAST MULTICAST  MTU:1500  Metrik:1   and route -ne has the following output:    Ziel            Router          Genmask         Flags   MSS Fenster irtt Iface 0.0.0.0         192.168.0.10    0.0.0.0         UG        0 0          0 wlan0 192.168.0.0     0.0.0.0         255.255.255.0   U         0 0          0 wlan0   I also stoped dhcpcd, the IPs aren't in the dhcp IP pool of the router and with one static IP everything works fine  Does anyone have any clue what I did wrong?
103463
I updated some entries in the  at C:\WINDOWS\System32\drivers\etc.  As a test, I decided to make Google point to 127.0.0.1.  # Additionally, comments (such as these) may be inserted on individual # lines or following the machine name denoted by a '#' symbol. # # For example: # #      102.54.94.97     rhino.acme.com          # source server #       38.25.63.10     x.acme.com              # x client host  127.0.0.1       localhost ::1             localhost 127.0.0.1       google.com   This works fine on Windows Vista, but not on Widows 7. When I type google.com into my browser, it goes directly to Google's website.  I am not using a proxy server, and I think there might be some temporary DNS settings that need to be flushed, but I'm not sure.  Does anyone know how to fix this?
61830
I am using Ubuntu 12.04.  My /etc/network/interfaces file consists of:    # The loopback network interface   auto lo   iface lo inet loopback     # The primary network interface   auto eth0  iface eth0 inet static   address 192.168.1.58   gateway 192.168.1.1 network 192.168.1.0   broadcast 192.168.1.255 dns-nameservers 66.212.63.228 66.212.48.10     I ran the command: /etc/init.d/networking restart  Which responded with:   *Running /etc/init.d/networking restart is deprecated because it may not enable again some interfaces   *Reconfiguring network interfaces...   RTNETLINK answers: File exists   Failed to bring up eth0   [ OK ]     Next I ran ping google.com and received:    ping: unknown host google.com   I am not sure if my interfaces refreshed. How do I properly configure my network with my static DNS addresses?