From: SMTP%"dhayes@hoasys.isd1.tafensw.edu.au" 28-OCT-1994 09:37:28.33 To: EVERHART CC: Subj: Re: LAT Problem X-Newsgroups: comp.os.vms,comp.sys.dec Subject: Re: LAT Problem Message-Id: <1994Oct28.110518.5853@hoasys> From: dhayes@hoasys.isd1.tafensw.edu.au Date: 28 Oct 94 11:05:18 +1000 Organization: TAFE NSW Network Lines: 98 To: Info-VAX@Mvb.Saic.Com X-Gateway-Source-Info: USENET In article , prep@yarrow.wt.uwa.edu.au (Paul Repacholi) writes... >> $ MCR LATCP CREATE LINK FDDI$LINK /DEVICE=FXA0 >> $ MCR LATCP SET NODE /STATE=ON >> > >Would it not be much better to run LAT on the ethernet, and decnet >on the FDDI? Can't imagine LAT getting into the 100Mb/s data >rate... WRONG!!!!!!!!!!!!!!!!!!!!! I am not just talking from the documentation, but 18 months of experience with FDDI and dual LAN controllers. I documented this in a post back on 20-Oct-1994. For those who only manage to keep 7 days of postings, I have attached an extract of that posting below. David ------------------------------------------------------------------------------ Extract from my previous posting on 20-Oct-1994... [snip] We installed FDDI on our cluster over 18 months ago and had numerous problems. It was not pleasant being on the bleading edge of technology, particularly since the only nodes we had on FDDI was our VAX 9000 production cluster! My memory is a bit fague but I will try my best... We received numerous patches of FYDRIVER, LAT & LAST to attempt to rectify our problems, some of these fixes were incorporated into VMS V5.5-2, and some were not. 1. When LAT is started on an ethernet controller under VMS V5.5 which does not have decnet running on it, it will continue to use the hardware address (08-00...). Under VMS V5.5-2, they changes LAT so that it will use the DECnet address (AA-00...), even if DECnet is not started. Therefore if you try to run DECnet over FDDI and LAT over ethernet your bridges/routers start to get very confused because they see the same ethernet address on two different LAN segments. *** While this feature was not documented in the VMS V5.5-2 release notes, *** it IS documented in the VMS V6.0 Release NOtes section 2.4.11.3 which *** states catagorically that "YOU MUST RUN LAT & DECNET OVER THE SAME *** CONTROLLER OF SCSSYSTEMID IS NOT 0" if the Ethernet and FDDI sections *** are bridged. 2. To force LAT to work over FDDI and ignore ethernet simply define LAT$DEVICE to be FXA in SYLOGICALS. We also define LAST$DEVICE the same way. $ DEFINE/SYS/EXEC LAT$DEVICE FXA $ DEFINE/SYS/EXEC LAST$DEVICE FXA (Note that we had problems with LAST (I think) if you defined it to point to FXA0) 3. We received numerous patches for FXDRIVER. The version we are running today is: X-24. This was a special copy of the image as it wasn't part of any CSCPAT kit when we got it. It probably is by now but I don't know the kit number. 4. We also have CSCPAT_0296015 installed with multiple LAST fixes. Although this kit says it applies to V5.5-1, it needed to be re-applied to V5.5-2. Again, there is probably a more recent kit. (LAST had nasty habits of crashing the machine without this patch!) 5. I assume you already have CSCPAT_0511 V3.4 or later as this has PAGES of LAT fixes, and MUST be re-applied after you upgraded to V5.5-2. 6. We also upgraded the DEMFA FIRMWARE from V1.3 to V1.4, but since yours is most likely a recent purchase you probably already have V1.4 or even V2.0. 7. I notice in you notes above that you have both MFA-0 and BNA-0 circuits enabled. As mentioned in point 1 above, having 2 ethernet adapters both using the same decnet ethernet address can cause problems. Even though it may appear to be working, close examination may find that some packets are being forwarded to your ethernet segment and some to the FDDI segment as the bridge/router switches its forwarding depending upon which segment it last received a packet from that address. Only run decnet over a single device. NCP> CLEAR/PURGE CIRCUIT BNA-0 ALL NCP> CLEAR PURGE LINE BNA-0 ALL I hope this helps. Regards, (and Good Luck!) David Hayes ----------------------------------------------------------------------------- David Hayes david.hayes@tafensw.edu.au TAFE-NSW Wrk: +61 2 950 1679 Australia Opinions expressed are my own, and not those of my employer.