Re: Ang: Re: Restore 21 to a new Iseries

On 11 Dec 2003 at 16:41, Jan.Rockstedt@xxxxxxxxxxxx wrote:

> Same version/release on both as/400.
> No op-console.

We had some fun with our twinax controllers. Basically, we had CTL02 and CTL03 
on
the 820. The 810 created a CTL01 (with the twinax console), so we switched 
stuff from
CTL02 to CTL01.

When normal ops started, we found twinax devices from CTL01 failing quite 
often. CTL02
was working fine.

Reason: Some OS/400 releases ago, IBM changed the twinax protocol and this 
interfered
with our twinax multiplexers. You can create a data area to switch to the old 
twinax versiion,
but you need this for each controller.

As we had no CTL01 on the 820, we didn't have that data area on the 810. 
Unfortunately, the
data area needs an IPL to get activated. Now it is working fine.

Another problem we found on tuesday (switch was on saturday). Client access 
sessions were
failing all over - no ping from pc to as400 and vice versa. A few minutes later 
it would work 
again. 

I found out that all failing pc's were on the x.x.67.* subnet, the 66.x subnet 
was working fine. 
Our network guy found the wrong subnet mask on our AS400 - 255.255.255.0 
instead 
of 255.255.254.0 (this would put 66.x and 67.x in the same subnet).

Well, you can't change subnet mask with active ethernet line => IPL. Now it 
works.

What's strange, we had been running with that wrong subnet mask on the 820 for 
a long time 
without problems? 

I dunno, but after each and every system upgrade, release upgrade or what ever 
(or during 
these things), we always met some unexpected problems - do we not prepare 
enough or is 
this just Murphy at its best?

Good luck,

Oliver