Before go in details about difference between 127.0.0.1 and 0.0.0.0 first let us understand what is IP address 127.0.0.1 and 0.0.0.0?
What is IP Address 127.0.0.1?
127.0.0.1 is the loopback Internet address protocol (IP) address additionally observed because the“localhost.”The address is help to establish connection to the local machine or computer being used by the end-user.This ip address is assigned to computer even if computer is not connected to internet.
The same convention is defined for computer’s that support IPv6 addressing using the connotation of ::1. Establishing a connection using the address 127.0.0.1 is the most common practice; however, using any IP address in the range of 127...* will function in the same or similar manner. The loopback construct gives a computer or device capable of networking the capability to validate or establish the IP stack on the machine.
IP Address 127.0.0.1 falls in the Class A also known as Special IP address.Communication and data transfer between this IP address not appear in the any network .This IP Address is used to test the TCP/IP protocol implementation on a host.Range of IP address is from 127.0.0.1 to 127.255.255.254
What is IP Address 0.0.0.0?
"0.0.0.0" is a valid address syntax. So it should parse as valid wherever an IP address in traditional dotted-decimal notation is expected. Once parsed, and converted to workable numeric form, then its value determines what happens next.
The all-zero value does have a special meaning. So it is "valid", but has a meaning that may not be appropriate (and thus treated as not valid) for particular circumstances. It is basically the "no particular address" placeholder. For things like address binding of network connections, the result can be to assign an appropriate interface address to the connection. If you are using it to configure an interface, it can remove an address from the interface, instead. It depends on the context of use to determine what "no particular address" really does.
In the context of a route entry, it usually means the default route. That happens as a result more of the address mask, which selects the bits to compare. A mask of "0.0.0.0" selects no bits, so the compare will always succeed. So when such a route is configured, there is always somewhere for packets to go (if configured with a valid destination).
In some cases, merely "0" will also work and have the same effect. But this is not guaranteed. The "0.0.0.0" form is the standard way to say "no particular address"
In the Internet Protocol version 4 the address 0.0.0.0 is a non-routable meta-address used to designate an invalid, unknown or non applicable target. To give a special meaning to an otherwise invalid piece of data is an application of in-band signaling.
In the context of servers, 0.0.0.0 means "all IPv4 addresses on the local machine". If a host has two ip addresses, 192.168.1.1 and 10.1.2.1, and a server running on the host listens on 0.0.0.0, it will be reachable at both of those IPs.
In some cases, merely "0" will also work and have the same effect. But this is not guaranteed. The "0.0.0.0" form is the standard way to say "no particular address"
In the Internet Protocol version 4 the address 0.0.0.0 is a non-routable meta-address used to designate an invalid, unknown or non applicable target. To give a special meaning to an otherwise invalid piece of data is an application of in-band signaling.
In the context of servers, 0.0.0.0 means "all IPv4 addresses on the local machine". If a host has two ip addresses, 192.168.1.1 and 10.1.2.1, and a server running on the host listens on 0.0.0.0, it will be reachable at both of those IPs.
In the context of routing, 0.0.0.0 usually means the default route, i.e. the route which leads to "the rest of" the internet instead of somewhere on the local network.
Difference between 127.0.0.1 and 0.0.0.0?
127.0.0.1 is the loopback address (also known as localhost).
0.0.0.0 is a non-routable meta-address used to designate an invalid, unknown or non applicable target (a no particular address placeholder).
In the context of a route entry, it usually means the default route.
In the context of a route entry, it usually means the default route.
In the context of servers, 0.0.0.0 means "all IPv4 addresses on the local machine". If a host has two ip addresses, 192.168.1.1 and 10.1.2.1, and a server running on the host listens on 0.0.0.0, it will be reachable at both of those IPs.
