I heard that the destination address in a packet can't be

Is there other IP address which can't be the destination address in a packet?


  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
    – Ron Maupin
    Commented Dec 15, 2019 at 1:17

1 Answer 1


Technically, any IP address is routable. That means any IP address could be routed, even

The limitation are administrative. Some rules have been written regarding the usage of IP addresses. The organism that manage IP addresses blocks is the IANA.

The IANA reserved some address for special uses and so, depending on those uses, some IP addresses must/should not be routed.

Those rules are sometimes enforced in the routers software, but not always. Some addresses can be routed in an internal network, but not on the Internet (the famous "private" IP addresses, like 192.168.X.X)

For IPv4, you will find the detail of those special purpose IP addresses on this IANA page:

IANA IPv4 Special-Purpose Address Registry

Here is an extract from this page

enter image description here

As you can see some addresses can be seen as a source address but not as a destination (thus are not routable)

The column that matters for your question is the "Forwardable" one. If it is set to false, those addresses should not be routed.

A router that receive such a destination address must drop the packet. It will either do it silently or send back an ICMP error message to the originator, depending on the type of address and the software implementation of the router.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.