EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  <20052006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  <20052006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
<== Date ==> <== Thread ==>

Subject: RE: CA for IOCs w/ dual NICs
From: "Jeff Hill" <[email protected]>
To: "'Andrew Johnson'" <[email protected]>, "'Kate Feng'" <[email protected]>
Cc: <[email protected]>
Date: Wed, 20 Apr 2005 10:32:11 -0600
> If both interfaces have addresses in the same IP 
> subnet, no server application can control which
> interface will get used for the TCP socket connection.  
> This is a limitation of the TCP/IP networking kernel, 
> not of the EPICS CA server software, so don't wait for 
> Jeff to try and fix it because I don't believe he can.

Strictly speaking, with the portable CA server library we have
the EPICS_CAS_INTF_ADDR_LIST configuration parameter. If Kate
were to set this parameter to the IP address of a network
interface then this server would receive TCP and UDP messages
only from the specified interface. I have not tested this in a
situation where the two network interfaces were on the same IP
subnet, but I believe that it would work. Of course, that
configuration option is currently not supported by the original
CA server still in use in the R3.13 and R3.14 IOC.

Jeff


> -----Original Message-----
> From: Andrew Johnson [mailto:[email protected]]
> Sent: Tuesday, April 19, 2005 2:27 PM
> To: Kate Feng
> Cc: Jeff Hill; [email protected]
> Subject: Re: CA for IOCs w/ dual NICs
> 
> Kate Feng wrote:
> >
> > What I wish for CA server is that NIC2 does not "receive UDP
> search
> > messages and or connect TCP circuits destined for  NIC1 of
> the IOC and
> > other interfaces".   This  seems to match with the
> capabilities you
> > described.
> 
> You can arrange that with the existing software as long as you
> put NIC2
> on a different subnet than NIC1.  If both interfaces have
> addresses in
> the same IP subnet, no server application can control which
> interface
> will get used for the TCP socket connection.  This is a
> limitation of
> the TCP/IP networking kernel, not of the EPICS CA server
> software, so
> don't wait for Jeff to try and fix it because I don't believe
> he can.
> 
> - Andrew
> --
> Podiabombastic: The tendency to shoot oneself in the foot.


References:
Re: CA for IOCs w/ dual NICs Andrew Johnson

Navigate by Date:
Prev: Re: CA for IOCs w/ dual NICs Andrew Johnson
Next: Job Openings for Magdalena Ridge Observatory (MRO) Interferometer - Program Director and Program Manager Chethan Parameswariah
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  <20052006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
Navigate by Thread:
Prev: Re: CA for IOCs w/ dual NICs Andrew Johnson
Next: RE: CA for IOCs w/ dual NICs Liyu, Andrei
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  <20052006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
ANJ, 02 Sep 2010 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·