Using The Set Subnet Mask Option - Cabletron Systems IRM-2/LM User Manual

USING THE SETUP OPTION
5.1.4

Using the Set SubNet Mask Option

Note: Consult your Network Administrator prior to setting the SubNet
Mask.
The SubNet Mask defines how your IRM2 treats SNMP trap IP
destination addresses in its Community Names table. Use the Set SubNet
Mask option in conjunction with the Set Default Gateway option.
Set the SubNet Mask when:
• workstations in the Community Names table reside on a different
subnet (i.e., across a gateway or router), and you want these
workstations to receive SNMP traps.
Use the SubNet Mask factory default setting of 0.0.0.0 when:
• all trap designated workstations are on the IRM2 subnet.
Using the SubNet Mask, the IRM2 logically determines one of two
possible locations, wither on or not on its own subnet, for each trap IP
destination address in its Community Names table. If the address is on its
own subnet, the IRM2 transmits directly to the workstation with that
address. If the address is not on its subnet, the IRM2 transmits to the
workstation with that address combined with the router IP address in its
default gateway.
To set the SubNet Mask:
1. Use the arrow keys to highlight the Set SubNet Mask field.
2. Enter the mask into the field using dotted decimal notation. The format
for this entry is XXX.XXX.XXX.XXX, with value of XXX ranging
from 0-255.
3. Press Return. If you enter an illegal mask in step 2, the error message
"Illegal Information Entered" appears on the screen.
4. Use the arrow keys to highlight the SAVE SETUP option at the
bottom of the Setup screen.
5. Press Return. The message "Modified Screen Information Has Been
Saved!" appears on the screen.
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