DECnet no longer works after transferring network port

[roose]

Hi Folks,

I would just like to get an advice from the group about a problem I faced with my test server. Eversince the port where my test server was connected to was transferred to another one, my DECnet no longer worked. I am not able to do a SET HOST to/from my production servers but I am still able to do TCP/IP stuff like telnet and FTP to and from the server. The IP address is still the same, it was just a physical move of my network cables.

I have already raised this problem to our network team but they said that everything should be working fine since I am able to do TCP/IP stuff. I have also tried doing a NET$CONFIGURE but still no success. I am suspecting that this might be due to the setup of the new network port as nothing else was changed on my system. What do my network team need to check on the port setup (Cisco switch)?

[Jon Pinkley]

They have probably separated you from the other nodes with a TCP/IP only router.

Does this still work?

$ set host 0

If that works, but the other doesn't, then it is most likely a router that is causing your problem.

What version of DECnet are you using? My guess is Phase IV.

Give output from these commands:

$ show system/noprocess ! VMS version
$ show network

This will give us a bit more to go on.

Also, when you say transferred to another port, what do you mean?

Jon

[Hoff]

DECnet is not IP, and connectivity of IP here shows only that the wiring mostly works -- and not that the DECnet protocol stack works.

You will want to consider a migration to DECnet-Plus over IP, since that's what your networking team will seemingly inevitably and more overtly request. DECnet-Plus over IP gives you your DECnet connectivity, and gets you onto the same IP protocol stack that most every router provides.

Pending the arrival of the ultimatum "use IP" request (and make no mistake, it's coming), the Cisco team needs to look at moving the new host MAC onto the existing DECnet virtual LAN. Or the Cisco folks will have to set up the router box you are now attached to as a DECnet router.

Stephen Hoffman
HoffmanLabs LLC

[roose]

Sorry for the initial lack of information: we are on OpenVMS v7.3-2, TCP/IP v5.4 ECO 5 and DECnet phase V.

The physical move of my network cable that I am saying here is that the my ethernet cable was moved from 1 switch's port to another one, while maintaining my IP addresses (2 IP interface with 2 different IP address).

As I am no longer onsite now, I'll try to provide additional information tomorrow. But so far, doing a SET HOST 0 did work.

[Volker Halle]

Roose,

also consider to look at the LAN device counters for the DECnet protocols with SDA or use the equivalent NCL commands for the routing circuit counters. Does your node receive any DECnet packets at all ? Does your node send any ?

$ ANAL/SYS
SDA> SHOW LAN

for the device units with protocols DECNET or DECNETV, then issue a

SDA> SHOW LAN/DEV=Exxn

and have a look at the counters.

Volker.

[Hoff]

With Cisco and most other similar equipment, the routers can know from MAC addresses, and from switch ports. Cisco networks are usually virtual network, and are operationally quite different than the classic wired network or the SMB and SOHO unmanaged switches and such.

When the Cisco team gets done with the typical virtualized configuration, the DECnet nodes can be completely oblivious that there are any other networks around, and entirely isolated -- they might well connect in and out via IP as well, but the Cisco folks will tend to keep traditional DECnet and related MOP and SCS and other such traffic quarantined within specific virtual LANs.

That you are running DECnet-Plus does not imply that you are running DECnet over IP, merely that you can configure and can run DECnet over IP.

Barring protocol-level blocking configured within the switches (which is easily feasible), the switches will route DECnet over IP traffic transparently with other IP traffic. The information you have provided and your question here implies the switch ports are not set for DECnet-Plus (DDCMP, OSI, etc) traffic and routing, and are not set to allow your new port onto the DECnet virtual LAN, and further imply that your current DECnet-Plus network is not operating over IP; that the PWIP stuff is not enabled and running.

[Allan Bowman]

If everything worked on one switch port and now doesn't work on another port on the same switch, you should be able to just tell your switch people to allow DECnet on the new port.

I used to manage multiple systems that were hosted on a customer's WAN. When we discovered that there was a conflict between our DECnet addresses and theirs at one location, they simply "disallowed" DECnet on that particular location's router port. This was not a problem for us since we used DECnet over IP to talk to our systems at other locations and only needed DECnet passed on the LAN.

Allan in Atlanta

[roose]

Re-did the NET$CONFIG and everything went okay. Thanks.