Re: HMC RMC IPv4?

Raul,

I've tried adding an IPv6 address to our development LPAR. I can ping the
HMC's IPv6 address from the LPAR, but diagrmc still shows the RMC connection
to the development LPAR is active but unusable. An lssyscfg -r lpar shows
the rmc_ipaddr parameter is set to one of the LPAR's IPv4 addresses. Would
that have to be changed to its IPv6 address? Can that parm be changed on a
running LPAR, or would that require an IPL? I'm not spotting where in the
LPAR's profile that its RMC IP address is configured.

On Fri, Apr 26, 2019 at 01:07:27PM -0400, Raul Jager wrote:

The wait for IPv6 before use IPv4 was fixed long ago, but there are
still people disabling IPv6 because of that.

Now the protocol is to try both together and use the one that responds
first.  If IPv6 is enabled, but without routes, then IPv4 will respond
as usual, but, since IPv6 is faster, if it has available routes, the
system will prefer it.

On 4/26/19 11:52 AM, Roberto José Etcheverry Romero wrote:

I think a lot of IBM i troubles came exactly from the system trying dns
resolution and a few other things thru ipv6 first. Did they finally fix
that? I've disabled ipv6 on all my recent installs due to that (and that
the customers dont even know ipv6 exists...)


On Fri, Apr 26, 2019 at 12:06 PM Raul Jager <raul@xxxxxxxxxx> wrote:

On 4/26/19 8:44 AM, Kevin Monceaux wrote:

Shaun,

On Fri, Apr 26, 2019 at 02:04:04AM +0000, Shaun Ryan wrote:

BUT
an RMC rebuild on the HMC may be the only way forward - this of course
requires a pesh password for HMC root access.

That's what I'm suspecting. But while I'm waiting for the point where I

can

acquire a pesh password from IBM, I'll keep searching in the hopes that
there's something that doesn't require root access that I haven't tried

yet.

I will also read up on IPv6. Before I disabled IPv6 on the HMC, it had

an

auto generated IPv6 address. IPv6 is enabled on our IBM i LPARs, but

they

only have ::1 loopback addresses assigned. Our HMC and POWER8 box are on
the same switch. Would assigning them IPv6 addresses be enough to get

them

talking over IPv6?

Yes. ADDTCPIFC with an IPv6 address will create the interface, next you
need to start it and you can work in "dual stack" There is a range for
"internal" IPv6 addresses, the prefix is fd next add an IPv6 address to
your PC and you can comunicate in IPv6 only (over a network capable of
both protocols. See: https://simpledns.com/private-ipv6

Long time ago, somebody had the "genial" idea of promoting the use of
IPv6 by using a protocol that tried first IPv6 and only used IPv4 after
the timeout failure. The result was opposite to the intended one,
instead of configuring dual stack, lots of people disabled IPv6, and
even if that protocol has been changed, some people still recommend
disabling IPv6.

At present the protocol for dual stack is to send the request on both
IPv4 and IPv6 at the same time, and use the one that responds first.
Since IPv6 is faster, when both are available, IPv6 will be used most.

-- Este e-mail fue enviado desde el Mail Server del diario ABC Color --
-- Verificado por Anti-Virus Corporativo Symantec --
--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxxxxxxxx
Before posting, please take a moment to review the archives
at https://archive.midrange.com/midrange-l.

Please contact support@xxxxxxxxxxxx for any subscription related
questions.

Help support midrange.com by shopping at amazon.com with our affiliate
link: https://amazon.midrange.com

-- Este e-mail fue enviado desde el Mail Server del diario ABC Color --
-- Verificado por Anti-Virus Corporativo Symantec --
--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxxxxxxxx
Before posting, please take a moment to review the archives
at https://archive.midrange.com/midrange-l.

Please contact support@xxxxxxxxxxxx for any subscription related questions.

Help support midrange.com by shopping at amazon.com with our affiliate link: https://amazon.midrange.com