Re: Cannot connect with Telnet client, other TCP/IP clients

[Pete Helgren <pete@xxxxxxxxxx>]

Thanks Jim.
(And John, the QAUTOCFG is 1 and the QAUTOVRT is 200)

The route list is pretty simple since I have only the local host and 
this one Ethernet adapter defined:

     Route            Subnet           Next Route
Opt  Destination      Mask             Hop Available
     127.0.0.0        255.0.0.0        *DIRECT            *YES
     192.168.200.0    255.255.255.0    *DIRECT            *YES
     224.0.0.0        240.0.0.0        *DIRECT            *YES
     224.0.0.0        240.0.0.0        *DIRECT            *YES
     *DFTROUTE        *NONE            192.168.200.2      *YES

I would have *expected* a route like this to be present as well:
     192.168.200.0    255.255.255.0    192.168.200.2      *YES

I DO see that route on the 520 and I would have expected the routing 
logic to send all 192.168.200.0 traffic to the 192.168.200.2 host 
because it was on the same subnet.   Not sure what *DIRECT means but I 
assume that it thinks all the hosts for 192.168.200.0 are local and 
don't need to go out the gateway.  I am beginning to think that 
something is wrong deep in the bowels of TCP/IP.  Perhaps an IPV6 issue 
(I have seen some of that in other areas but not on the i).

As an interesting side note: When I deleted the original interface, 
route and then line and recreated them, I got a "failed" status when I 
first attempted to start the interface. The job log said that there was 
another adapter that already had that IP address (there wasn't).  Turns 
out that the controller and device that was created when line started 
didn't get deleted along with the line.  I originally played with an 
alternate addresses thinking I had a duplicate on the network and it 
turns out it was the "old" descriptions carried by the original line.

Perhaps I'll give IBM a ring and see what they think.

Pete Helgren
Value Added Software, Inc
www.petesworkshop.com
GIAC Secure Software Programmer-Java

On 8/1/2012 5:14 AM, Jim Oberholtzer wrote:
> Pete;
>
> Yesterday I had very similar difficulties at a client.  Differences are
> this is P6, HMC console,  and LPARs but I don't think that's a factor
> since you were able to get in with the LAN console.  Routing on this box
> is correct, although that could be a problem for you as well.    We just
> restarted the telnet server and it started working without having to
> recreate anything.  We have experienced similar problems with the SMTP
> server as well.  I'm starting to wonder if there is a fault somewhere
> deep in TCP.   We have a PMR open and are working it actively however
> every time we try to trace it, we do not see a failure.
>
> We were planning on getting all the most recent PTFs/Groups etc hoping
> there was a problem that was fixed but it seems you have debunked that
> theory.  That system is not that far back in PTFs anyway but it never
> hurts to hope...
>
> In the mean time try a telnet server restart.   Have you tried NETSTAT
> to see if the route is valid?
>
> Jim Oberholtzer
> Chief Technical Architect
> Agile Technology Architects