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* The network has no notion of application names, and has to use a combination of the interface address and transport layer port number to identify different applications. In other words, the network uses information on ''where'' an application is located to identify ''which'' application this is. Every time the application changes its point of attachment, it seems different to the network, greatly complicating multi-homing, mobility, and security.
Several attempts have been made to propose architectures that overcome the current [[Internet]] limitations, under the umbrella of the [[Future Internet]] research efforts. However, most proposals argue that requirements have changed, and therefore the Internet is no longer capable to cope with them. While it is true that the environment in which the technologies that support the Internet today live is very different from when they were conceived in the late 1970s, changing requirements are not the only reason behind the Internet's problems related to multihoming, mobility, security or QoS to name a few. The root of the problems may be that current Internet is based on a tradition focused on keeping the original [[ARPANET]] demo working and fundamentally unchanged, as illustrated by the following paragraphs.
'''1972. Multi-homing not supported by the ARPANET'''. In 1972 the [[Tinker Air Force Base]] wanted connections to two different IMPs ([[Interface Message Processors]], the predecessors of today's routers) for redundancy. [[ARPANET]] designers realized that they couldn't support this feature because host addresses were the addresses of the IMP port number the host was connected to (borrowing from telephony). To the ARPANET, two interfaces of the same host had different addresses, therefore it had no way of knowing that they belong to the same host. The solution was obvious: as in operating systems, a logical address space naming the nodes (hosts and routers) was required on top of the physical interface address space. However, the implementation of this solution was left for future work, and it is still not done today: “IP addresses of all types are assigned to interfaces, not to nodes”.<ref name="IPv6">R. Hinden and S. Deering. "IP Version 6 Addressing Architecture". {{IETF RFC|4291}} (Draft Standard), February 2006. Updated by RFCs 5952, 6052</ref> As a consequence, routing table sizes are orders of magnitude bigger than they would need to be, and multi-homing and mobility are complex to achieve, requiring both special protocols and point solutions.
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