Installation guide

1-10 B
LACK
D
IAMOND
H
ARDWARE
I
NSTALLATION
G
UIDE
B
LACK
D
IAMOND
O
VERVIEW
MSM B
EHAVIOR
The BlackDiamond 6800 can run with a single MSM installed. When a second MSM is
used, one of the MSMs is selected to be the master MSM, and the other becomes the
slave MSM.
The master MSM is responsible for upper-layer protocol processing and system-
management functions. For example, OSPF computation and SNMP functions are
performed by the master MSM. Packet handling is distributed among the four CPUs on
both MSMs.
Selection of the master MSM occurs automatically. The following scenarios describe the
selection process:
• When the BlackDiamond 6800 boots with both MSMs already installed, the MSM in
Slot A becomes the master.
• When the BlackDiamond 6800 boots with a single MSM (regardless of the slot), it is
selected as the master. If another MSM is added to the system while powered on, the
added MSM becomes the slave. The slave MSM can be inserted and de-inserted in
the chassis without disruption of network services.
If you de-insert the master MSM while the BlackDiamond 6800 is running, the slave
MSM does a soft reset and becomes the master MSM.
When you save the software configuration, it is saved to both MSMs. If you download a
new image, the image is downloaded to both MSMs.
MSM M
EMORY
The MSM has two 168-pin DIMM sockets, and ships with one 64MB SDRAM module
installed, as shown in Figure 1-4. In the future, the memory capacity with be increased
by either replacing the 6 MB DIMM with a new one, or by adding a second DIMM to
the empty socket.