Arbitrary loopback ip addresses besides 127.0.0.1

Question

trying to setup nginx to serve anarchistparty.org synapse homeserver reverse proxy. Nginx.conf is currently standard install, hasn’t been edited.

Sudo nginx -t gives:

nginx: [emerg] open() "/etc/nginx/sites-enabled/anarchistparty.org" failed (2: No such file or directory) in /etc/nginx/nginx.conf:62 nginx: configuration file /etc/nginx/nginx.conf test failed

anarchistparty.org is present in sites-available and symlinked

Solution 1

Edit /etc/network/interfaces

add the following at the bottom of the file

auto lo:0
iface lo:0 inet static
address 127.0.0.2
netmask 255.0.0.0

Documentation on interfaces file can be found here : http://manpages.ubuntu.com/manpages/lucid/man5/interfaces.5.html

The definition above firstly tells the system to automatically bring the new lo:0 virtual interface (alias) up when the system starts. Then it sets interface lo:0 (bound to the loopback interface) to be a static address. The last two lines set the address and the netmask.

After you have added the above you will need to restart networking

sudo /etc/init.d/networking restart

or reboot the computer.

Solution 2

The whole 127.0.0.1/8 address space is reserved for loopback addresses. So you can use any address from 127.0.0.1 up to 127.255.255.254.

Comments

[Majid Fouladpour]

+1, good to know fact. However, I tried 127.0.0.5 with my browser and I get (111) Connection refused error. So, I guess I should try the method @Sam suggests.

[Kind Contributor]

They're reserved, but not available for applications unless the interface(s) are added. see askubuntu.com/questions/444124/how-to-add-a-loopback-interfa‌​ce/…. For contrast, on Windows, the full range is bindable without manually adding more interfaces.

[Ihtisham Tanveer]

spelling mistake /ect/nginx/sites-enabled/ corect path. sudo ln -s /etc/nginx/sites-available/anarchistparty.org /etc/nginx/sites-enabled/