Re: arp table - same mac address shows two ip addresses

On 10/18/2018 10:19 AM, Erik Auerswald wrote:
> Hi,

Hi,

> The original question was a bit scarce on details, thus I substituted 
> pertinent experience of my own. This is not necessarily easy to follow. ;)

Fair enough.

> Please tell us about your results.

Will do.

My intention is to create the following configuration using network 
namespaces:

(A)---1---(B)---2---(C)

Where A, B, and C are the test network namespaces and 1 and 2 are vEth 
pairs between them.

I was originally going to start with one test, see if A could 
communicate with B via 2.B.

After your earlier email about hosts moving from one physical network to 
another, I'm going to see if 1 can be configured with 2.A and 
communicate with 2.B via the 1 network.

I'll share the commands I use to create the lab topology and subsequent 
commands to test.

> In IPv6, addresses are assigned to interfaces. This is obvious with 
> link-local addresses, but true for differently scoped addresses as 
> well. I am sorry, but I do not know the RFC off the top of my head.

Fair enough.

> OK, had to search...

;-)

Thank you.

> RFC 8200, Internet Protocol, Version 6 (IPv6) Specification, section 2:
> 
>      "interface    a node's attachment to a link."
>      "address      an IPv6-layer identifier for an interface or a set of
>                    interfaces."
> 
> RFC 4291, IP Version 6 Addressing Architecture, section 2.1:
> 
>      "IPv6 addresses of all types are assigned to interfaces, not nodes."

That is quite succinct.  I'm glad that's codified.

> IPv6 is an interesting rabbit hole to dive into. ;)

Yep.

I've done a fair bit with IPv6 at a shallow level.  I'm now going to be 
reading more and getting into a deeper level.

> They might even be a bit simpler to use without a 100% correct networking 
> configuration. ;)

I think that a single homed machine with a single IPv4 address (ignoring 
loopback) is quite simple.  Even if it has a routing table with more 
than a default gateway.

> Likewise. :)

:-)



-- 
Grant. . . .
unix || die