NEXPEED NBG440 User’s Manual
NexComm Systems, Inc. 77 PAGE
[<expressions>]
src <address> - Specify a source IP address (Possible to omit)
dst <address> - Specify a destination IP address (Possible to omit)
<address> = A.B.C.D/M[:<lport>[-<hport>]]
A.B.C.D : IP address
M : Subnet mask value (the number of ‘1’ bits)
<lport>[-<hport>] : low num – [high num]
- Port number (TCP) or ID number (ICMP)
Attention:
If the block filter is chosen to setup, all other packets that have no relation with the
block filter will pass through. If the pass filter is setup, however, all other packets that have no
relation with the pass filter will be blocked. Therefore, the pass filter requires an additional filter
that can take care of those packets that are not under the control of the pass filter.
Viewing the filters
To display the filters, type the following command:
COMMAND
(conf)# show filter
Enabling IP filtering
You can enable IP filtering at layer 2 or layer 3. If you configure the NBG440 as a
bridge, enable at layer 2. If you configure the NBG440 as a router, enable at layer 3. As
soon as enable filtering, the defined filter takes effect immediately.
To enable filtering, type the following command:
COMMAND
(conf)# filter enable layer 2
(conf)# filter enable layer 3
To stop filtering, type the following command:
COMMAND
(conf)# filter disable layer 2
(conf)# filter disable layer 3
