Experimental Physics and
Industrial Control System

[email protected] (Jeff Hill) · Wed, 17 Jun 1998 16:39:30 -0600

Maren, Ned,

On Wednesday, June 17, 1998 12:50 PM, Maren Purves [SMTP:[email protected]] wrote:
> After having changed architecture from hkbaja60 to hkbaja47
> and IOC (crate) I ran into the following problems:
> - the hkbaja47 is only able to boot (load vxWorks) with one user id.
> I can't find any protection problems. It is not dependent on the host it
> boots from (at least).
> - after getting it to boot, I find that, while everything in the
> startup file appears to get executed ok, and checking with dbpr that
> the records actually process, my dm screen tells me that all the
> channels are disconnected. caRepeater is running, I took all access
> restrictions out of the resource.def file (and actually switched to
> doing the iocInit without file specification)

The ARP protocol is used to dynamically discover the physical address of
the host that has a particular IP address. Hosts use ARP only initially
when they don't know the physical address that corresponds to a particular IP
address. Subsequently, an ARP cache is consulted for all future 
communication with the remote host.

When you move an IP address from one physical Ethernet address
to another you need to reinitialize the ARP cache on all hosts that 
have used the old physical Ethernet address/IP address combination
in the past. 

On Solaris this can be accomplished by typing "arp -d <host name>"
as superuser, or by rebooting the host.

Jeff

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System