Re: [v6ops] WGLC: draft-ietf-v6ops-unique-ipv6-prefix-per-host-02 - multiple prefixes per device

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Fred,

>> A little flippant perhaps, but can you give an example of a node that isn't a router anymore?
>> I think the statement "All hosts are routers" is almost true.
>> 
>> Certainly my phones, laptops, lightbulbs are all routers.
> 
> </hat>
> 
> I'd like to understand your meaning, if you don't mind.
> 
> A router, per RFC 2460, is a system that receives a message, does no processing on its content, but repeats it to another system. A host is one that receives messages and processes their application layer content.

2460: router      - a node that forwards IPv6 packets not explicitly addressed to itself.

> I think it's fair to say that an iPhone etc has more than one interface; WiFi and LTE, perhaps. A laptop often has several interfaces such as physical and wireless Ethernet, USB, Bluetooth, and other things. Having multiple interfaces, however, does not qualify it as a router; what qualifies it as a router is when it receives a message and repeats it, usually on another interface.

Phones act as routers when they do tethering.
My laptop acts as a router when the hypervisor running on bare metal routes traffic between the physical NICs and a set of VMs and containers.

> Yes, an iPhone acting as a hot spot can route between its WiFi and LTE ports. If it is not configured as a hot spot, however, it generally uses its many interfaces as ways to receive messages, pass them to applications, and respond to them. Absent a specific (and unusual) configuration, an iPhone therefore is a host, not a router.

Correct, and switching between the two requires a single swipe with suitable finger.
And my lightbulbs, builds up a mesh and forward packets for each other. Aka router.

> Are you and I using the words in the same way? I get the feeling that you see multiple interfaces and infer "router".

No.
Sure, many nodes can be configured to act either as hosts or routers. In IPv4 the typical case is that it pretends to be a host northbound  to the network. Unfortunately that's how it is likely to pan out in IPv6 too...

Cheers,
Ole