"Brett" == Brett Bump <bbump at rsts.org> writes:
Brett> Marc you might also double check your cabling (in fact even
Brett> change them). As I recall, DECnet (like IPX) is not an error
Brett> correcting protocol. I've worked on networks where TCP will
Brett> error correct for poor cabling while the Novell connections
Brett> fell flat on their faces. This could explain why your IP
Brett> connection seems to work fine, but you have no DECnet
Brett> connectivity.
That seems strange.
DECnet (NSP) is just like TCP in that it handles lost packets. Bad
cables will produce lost packets but they will not produce corrupted
packets. Corrupted packets are caused by defective switches or
routers. Bad cables only cause CRC errors. (Well, except for the
EXTREMELY low probability of a random error getting past the Ethernet
CRC.)
You're right that TCP detects corrupted packets (some of them, anyway
-- TCP checksum is pretty weak) while NSP does not. But if you see
TCP checksum errors, the way to fix them is not to change the cabling,
but the defective switches/routers.
paul
On Mon, 6 Apr 2009, Marc Chametzky wrote:
I think I'm going to set up MultiNet on the Alpha and try using a TCP
circuit between LULU and DUSTY. This will tell me whether it's a DECnet
routing issue or an Ethernet packet one.
Well, with a DECnet-over-IP circuit instead, it's working just fine with
both nodes seeing each other's adjacency, and from LULU I can connect to
LEGATO.
So, some sort of Personal Alpha networking glitch. That's surprising
since I do have the two nodes clustered, so that's working. I wonder
what's not working right with DECnet routing multicasts.
Well, this may be suboptimal, but it works well enough and that's all
that matters.
--Marc
Marc you might also double check your cabling (in fact even change them).
As I recall, DECnet (like IPX) is not an error correcting protocol. I've
worked on networks where TCP will error correct for poor cabling while the
Novell connections fell flat on their faces. This could explain why your
IP connection seems to work fine, but you have no DECnet connectivity.
Brett
Hi All,
Virgin have been mucking me about a bit. I will be upgraded to a new
cable modem next week which will mean I'll get a new IP address for ZAPHOD.
However, in the mean time they've mistakenly disconnected me and
reconnected me to a different IP!
Zaphod's current IP address is 82.8.17.191, but that WILL change next
Wednesday afternoon (GMT) so it's up to you if you change the multinet
connection in the meantime ... I won't be offended if I'm off HECnet for
a week, I'm far too busy doing other things anyway :S
I'll post the new IP address next week,
Sorry for the outage ... but it's not my fault :-(
Chrissie
I think I'm going to set up MultiNet on the Alpha and try using a TCP circuit between LULU and DUSTY. This will tell me whether it's a DECnet routing issue or an Ethernet packet one.
Well, with a DECnet-over-IP circuit instead, it's working just fine with both nodes seeing each other's adjacency, and from LULU I can connect to LEGATO.
So, some sort of Personal Alpha networking glitch. That's surprising since I do have the two nodes clustered, so that's working. I wonder what's not working right with DECnet routing multicasts.
Well, this may be suboptimal, but it works well enough and that's all that matters.
--Marc
Are your nodes on?
As of right now, DUSTY's the only one that is.
CALHAN is down pending me figuring a new host for it since it didn't work right on Ubuntu JeOS (some VMware networking issue). LULU is disconnected while I install MultiNet and get a TCP circuit up between it and DUSTY for testing.
--Marc
You can do "NCP SET KNOWN LOGGING ALL" and the "REPLY /ENABLE" to see all
the DECnet events. That may give you a clue (or maybe not :-)
I apparently have that turned on already. Nope, not enough of a clue.
I think I'm going to set up MultiNet on the Alpha and try using a TCP circuit between LULU and DUSTY. This will tell me whether it's a DECnet routing issue or an Ethernet packet one.
--Marc
I wonder whether it's not getting some of the multicasts.
You can do "NCP SET KNOWN LOGGING ALL" and the "REPLY /ENABLE" to see all
the DECnet events. That may give you a clue (or maybe not :-)
Bob
