| Title: | DECnet/OSI for OpenVMS |
| Moderator: | TUXEDO::FONSECA |
| Created: | Thu Feb 21 1991 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 3990 |
| Total number of notes: | 19027 |
VMS/VAX V6.2
DECnet/OSI V6.3-ECO6
DECnis V4.0
FDDI
+-----+--------------------------------+---------------------+
| |
| NR-Ethernet |
| +------------+-------------+ |
| | | | |
+-----+--+---+ +----+-----+ +--+--+-----+ +-----------+
| DECnis | | VAX1 | | VAX2 | | VAX3 |
+-----+------+ +----+-----+ +-----+-----+ +-----+-----+
| | | |
+-----+---------------+----------------+---------------+-----+
R-Ethernet
I am working a customer time critical network problem.
The above diagram shows a simplified network configuration.
Traffic from VAX1 to VAX3 always goes via the R-Ethernet (Realtime) segment,
even though an indirect path exists via the NR-Ethernet (Non-Realtime) segment.
Traffic from VAX2 to VAX3 either goes via the FDDI/R-Ethernet or direct via
the R-Ethernet segment. Traffic from VAX2 to VAX3 may go via the R-Ethernet
for say 10 minutes and then switch to the FDDI, then sometime later switch
back to the R-Ethernet direct path. When using the FDDI path "NET$SDA show
routing cache" shows the reachability as indirect.
Where multiple Ethernet paths exist DECnet always uses the direct path.
However when an FDDI path exists DECnet will often use the indirect path via
the FDDI.
Why would DECnet use the Indirect Path via the DECnis router rather than using
the direct path?
Thanks,
Geoff..
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 3870.1 | BULEAN::LEE | Fri Feb 14 1997 11:22 | 6 | ||
When the FDDI large packet feature is turned on, an indirect FDDI
path is favored over a direct Ethernet path. To avoid this,
you need to turn off the FDDI large packet support, ie. set
the FDDI circuit type to the default CSMA-CD type.
If you still have problem, please log an IPMT case.
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