Collisions in VAX/VMS box

[Sk Noorul Hassan]

In my VAX server, collision light on Ethernet tranciever blinks continuously when running an application on it. But, it shows no collisions if we stop the application. Network group also find collisions on switch port to which this box is connected. Is there any way to know whether collisions are generated due to my VAX/VMS box problem or some external network problems ?

Please also suggest how to check collisions at VMS end .I have checked using "mcr ncp sh kn line counters"

[Wim Van den Wyngaert]

Use
$ mc lancp
show lan/char

to verify the settings of the LAN. Compare this with the setting on the switch. Should be the same.

$ mc lancp
show lan/count

to verify all kind of errors. Even if the interface is not configured for decnet (ncp).

Wim

[Volker Halle]

Hi,

what is the speed of the network card on your VAX server ? I don't think the VAX can do anything other than 10 mbit half-duplex. Is the switch port set to auto-negotiate ? Can you set it to fixed 10 mbit hdx ?

Do you see any increasing non-zero error counters in the NCP LINE COUNTERS ?

Volker.

[Ian Miller.]

Did you change anything recently? Previously did this report collisions?

[Sk Noorul Hassan]

In mcr ncp sh kn line counters, single & multiple collisions are showing 15000 & 10000 respectively as of now, but it is inceasing very fast. Do u want me to check any thing else ? Switch port is fixed to 10 MBPS.

MCR LANCP sho lan command does not exist in my vax. pls suggest

[Steven Schweda]

You could simply have a bad cable or other
hardware problem.

Also, you might get better advice if you would
reveal your VMS and DECnet versions.

[Sk Noorul Hassan]

VAX box has got VMS version 7.1 & DECNET Phase IV

[Volker Halle]

Could the switch possibly be set to 10 Mbps and FULL DUPLEX ?

A twisted pair piece of cable between a network card and a switch port is a really small LAN and you would not expect to see many collisions.

Volker.

[Bart Zorn_1]

Could this be the "heart beat", aka collision detect check?

Older DEC ethernet interfaces required this setting. Otherwise DECnet would complain.

AFAIK, for more recent ethernet cards, it doesn't make much of a difference if heart beat is on or off.

Anyway, it is likely a switch setting on the transceiver.

HTH,

Bart Zorn

[labadie_1]

Post the result of the command

$ mc ncp sh k line co
$ mc ncp zero k line co
$ wait 00:10:00
$ mc ncp sh k line co

and we will know if the heartbeat is badly positioned