Re: no channel access to IOC

[Luedeke Andreas <Andreas.Luedeke@psi.ch>]

Hi Andrew, hi Bob,
actually I tried to set the netmask this way to :ffff0000, but the
UDP of the IOC was still the same
192.168.10.255... Is the subnetmask somehow hardcoded in channel access?
As I pointed out, the netmask is arbitrary in this system, because it consist
only of one (or two) PCs and one IOC, no connection to the outer world.
So we tried both, to set it to a B-class subnet or to a C-class subnet
on both machines. None of this worked.
I will try it again tomorrow, maybe we missed something. Do you have
a link to the debugging tools at LANL, the link to the LANL site from http://www.cebaf.gov/accel/documents/epics_doc.html
is not valid anymore (requires authentication).

Thanks,
- Andreas

> Hi Andreas,
>         Are the net masks the same? Look at the debugging IOC slides on
> the LANL web site for finding the netmask - if you need to.
>         Bob

Andrew Johnson wrote:

Hi Andreas,

Luedeke Andreas wrote:
>
> [...] linboot.ioc.1066 > 192.168.255.255.5064: udp 32 (ttl 64, id [...])
...
> [...] iocLin.ioc.1031 > 192.168.10.255.5065: udp 16 (ttl 30, id [...])

These are broadcast addresses on two different subnets which is usually
why they can't communicate - you either need to set their subnet masks to
be the same on both machines, or if your network topology won't allow this
you'll need to set the EPICS_CA_ADDR_LIST environment variable to the
broadcast address of the other subnet (see the Channel Access reference
manual for details).  On an ioc use putEnv("VAR=value") to set this any
time before iocInit.

You can see the subnet mask by using ifShow at the vxWorks shell, and set
it by adding ":ffffff00" (without the quotes) after the target's IP
address in its boot parameters.  Replace the ffffff00 with whatever the
mask should be for its subnet.

- Andrew
--
Complexity comes for free, Simplicity you have to work for.

-- 
Andreas Luedeke, Controls Group, Swiss-Light-Source, PSI
mailto:luedeke@psi.ch, tel:+41-(0)56-310-4002, fax:-3351