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ucx telnet access, i'm missing something....

 
cgilley
Occasional Contributor

ucx telnet access, i'm missing something....

This has got to fall into the forehead slapping zone - I'm moving a VAX (5.5, running ucx) to a new network area.  But the users cannot telnet in to the vax using putty.  This is a very mature system, and I'm sure I have forgotten the obvious.  Bot of these "vaxes" are running in VMs using charon-vax.

From my laptop, I can ping both servers hosting the VMs, and I can ping the existing VAX, but the new vax remains unpingable.  This leads to my inability to telnet to it.

Something deep inside of me says their is something I forgot to do in ucx ...

what am I missing?

 

appreciate the obvious

7 REPLIES 7
Steven Schweda
Honored Contributor

Re: ucx telnet access, i'm missing something....

> [...] VAX (5.5, running ucx) [...]

      ucx show version

> [...] to a new network area. [...]

   Define "new".  What are the IP addresses of these systems?

> [...] users cannot telnet in to the vax using putty. [...]

   "cannot" is not a useful problem description.  An actual error
message might be more helpful.

> what am I missing?

   Can't tell without some info on the network configuration.  The VMS
system could simply have an IP address in the wrong subnet, and no route
to the right subnet.

cgilley
Occasional Contributor

Re: ucx telnet access, i'm missing something....

Not a mind reader?  i'm disappointed.  lol, yeah, I didn't provide much information. 

This is an old legacy system running OpenVMS 6.1, UCX 4.0 within the charon-vax emulation environment.  I'm in the process of migrating to a new virtual machine running in the customer's cloud.  The new installation is using the exact same disk files as the existing system.

The existing system is at 10.90.10.202.  I can access the system from my laptop.

I took the existing disk files, moved them to the VM and simply used UCX$CONFIG to change the new system's ip address to 10.90.10.186.  Can't ping this address, can't telnet into the machine.

The addresses are so close, I would not expect routing to pay an issue.

Forehead slap moment - Windows Server 2012 is probably doing this, not the vax.... I'll be back to close this issue out.

Volker Halle
Honored Contributor

Re: ucx telnet access, i'm missing something....

You need to also look at the CHARON-VAX network configuration and VMware network configuration !

Is the CHARON-VAX network interface correctly mapped to the dedicated Windows network adapter to be used by CHARON exclusively ? NDIS6 binding o.k. ?

Looking from VMS: do the counters of $ UCX SHOW INTERFACE show packets being sent and/or received ?

Does the CHARON NCC tool show packets being sent and/or received ?

Does the VAX use DECnet on the LAN interface (in addition to IP) ? If so, is the VMware LAN interface correctly configured (MAC address change enabled and promiscuous mode enabled) ?

Volker.

cgilley
Occasional Contributor

Re: ucx telnet access, i'm missing something....

Yes to all.  And good suggestions, thanks. The part I missed is that if I connect to the Server 2012 machine, I have no problem telneting or pinging the VAX.  I think I'm getting hammered by a group policy out in the customer's domain.

Chris Scheers
Advisor

Re: ucx telnet access, i'm missing something....

IIRC, Server 2012 enables ECN by default. ECN can interfere with some older TCP/IP stacks as its definition is not strictly upwards compatible. You might see if disabling ECN makes any difference. Also, do your testing on a box other than the host box so that the bits have to actually travel over a wire. If you are trying to communicate from the host box to an emulated/VM machine, TOE issues may come into play.
Brad McCusker
Respected Contributor

Re: ucx telnet access, i'm missing something....

I agree with prior statements, this sounds like a network problem on the host.  There are lots of considerations for networking CHARON in the cloud.  Follow the Stromasys documentation closely.  

Brad McCusker
Software Concepts International
cgilley
Occasional Contributor

Re: ucx telnet access, i'm missing something....

Turns out it's death by typos.  I changed the IP address and missed the route entry.

The route entry was left to the old server IP address....

 

thanks for the suggestions