SNMP Filter FAQs

This section answers some frequently asked questions by providing setup examples for SNMP filters. To use the information in the tables:

  1. Copy the information that you need from the table by: (a) selecting/highlighting the information, and (b) copying the information using Ctrl + C.

  2. Paste that information in the SNMP MIB object fields using Ctrl + V.

Examples

LLC filter (for Cisco IOS Release 12.0 T)

LLC filter (for Cisco IOS Release 12.1 T)

IP filter (for Cisco IOS Release 12.0 T)

IP filter (for Cisco IOS Release 12.1 T)

 

Logical Link Control Filter Examples

Basic logical link control (LLC) configuration is to accept only frames that carry IP or related protocols (example, ARP). All other LLC frames will be discarded on all interfaces.

To set up SNMP LLC filters, use the following procedures as examples.

Procedure

To create an LLC filter (for Cisco IOS Release 12.0 T), follow this procedure.

Field

Description

Usage Notes

Step 1

Set all traffic that does not meet at least one filter. Set the following MIB to the indicated value:

 

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterLLCDefault

1.3.6.1.3.83.1.6.1.0

Integer

1

Step 2

Set the following MIBs to the indicated values:

 

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterLLCStatus

1.3.6.1.3.83.1.6.2.1.2.1

Integer

4

docsDevFilterLLCProtocolType

1.3.6.1.3.83.1.6.2.1.4.1

Integer

2

docsDevFilterLLCProtocol

1.3.6.1.3.83.1.6.2.1.5.1

Integer

2048

docsDevFilterLLCIfIndex

1.3.6.1.3.83.1.6.2.1.3.1

Integer

0

docsDevFilterLLCStatus

1.3.6.1.3.83.1.6.2.1.2.2

Integer

4

docsDevFilterLLCProtocolType

1.3.6.1.3.83.1.6.2.1.4.2

Integer

2

docsDevFilterLLCProtocol

1.3.6.1.3.83.1.6.2.1.5.2

Integer

2054

docsDevFilterLLCIfIndex

1.3.6.1.3.83.1.6.2.1.3.2

Integer

0

 

 

 

To create an LLC filter (for Cisco IOS Release 12.1 T), follow this procedure.

Field

Description

Usage Notes

Step 1

Set all traffic that does not meet at least one filter. Set the following MIB to the indicated value:

 

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterLLCDefault

1.3.6.1.2.1.69.1.6.1.0

Integer

1

Step 2

Set the following MIBs to the indicated values:

 

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterLLCStatus

1.3.6.1.2.1.69.1.6.2.1.2.1

Integer

4

docsDevFilterLLCProtocolType

1.3.6.1.2.1.69.1.6.2.1.4.1

Integer

2

docsDevFilterLLCProtocol

1.3.6.1.2.1.69.1.6.2.1.5.1

Integer

2048

docsDevFilterLLCIfIndex

1.3.6.1.2.1.69.1.6.2.1.3.1

Integer

0

docsDevFilterLLCStatus

1.3.6.1.2.1.69.1.6.2.1.2.2

Integer

4

docsDevFilterLLCProtocolType

1.3.6.1.2.1.69.1.6.2.1.4.2

Integer

2

docsDevFilterLLCProtocol

1.3.6.1.2.1.69.1.6.2.1.5.2

Integer

2054

docsDevFilterLLCIfIndex

1.3.6.1.2.1.69.1.6.2.1.3.2

Integer

0

 

IP Filter Examples

This allows you to set up the default IP filter behavior. An example would be to block certain IP traffic and allow other IP traffic.

To set up SNMP IP filters, use the following procedures as examples.

Procedure

To create an IP filter (for Cisco IOS Release 12.0 T), follow this procedure.

Field

Description

Usage Notes

Step 1

Set the following MIB to the indicated value:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpDefault

1.3.6.1.3.83.1.6.3.0

Integer

2

Note: The default action is to accept all IP traffic.

Step 2

Set up filters 10 and 20 to discard UDP-based NetBIOS traffic. All UDP-based NetBIOS traffic (client or server) is discarded if the source or destination port is 137, 138, or 139. Set the following MIBs to the indicated values:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpStatus

1.3.6.1.3.83.1.6.4.1.2.10

Integer

4

docsDevFilterIpControl

1.3.6.1.3.83.1.6.4.1.3.10

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.3.83.1.6.4.1.4.10

Integer32

0

docsDevFilterIpDirection

1.3.6.1.3.83.1.6.4.1.5.10

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.3.83.1.6.4.1.6.10

Integer

2

docsDevFilterIpProtocol

1.3.6.1.3.83.1.6.4.1.11.10

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.3.83.1.6.4.1.12.10

Integer

137

docsDevFilterIpSourcePortHigh

1.3.6.1.3.83.1.6.4.1.13.10

Integer

139

docsDevFilterIpDestPortLow

1.3.6.1.3.83.1.6.4.1.14.10

Integer

0

 docsDevFilterIpDestPortHigh

1.3.6.1.3.83.1.6.4.1.15.10

Integer

65535

 

docsDevFilterIpStatus

1.3.6.1.3.83.1.6.4.1.2.20

Integer

4

docsDevFilterIpControl

1.3.6.1.3.83.1.6.4.1.3.20

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.3.83.1.6.4.1.4.20

Integer32

0

docsDevFilterIpDirection

1.3.6.1.3.83.1.6.4.1.5.20

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.3.83.1.6.4.1.6.20

Integer

2

docsDevFilterIpProtocol

1.3.6.1.3.83.1.6.4.1.11.20

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.3.83.1.6.4.1.12.20

Integer

0

docsDevFilterIpSourcePortHigh

1.3.6.1.3.83.1.6.4.1.13.20

Integer

65535

docsDevFilterIpDestPortLow

1.3.6.1.3.83.1.6.4.1.14.20

Integer

137

docsDevFilterIpDestPortHigh

1.3.6.1.3.83.1.6.4.1.15.20

Integer

139

Step 3

Set up filters 30 and 40 to discard TCP-based NetBIOS traffic. Set the following MIBs to the indicated values:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpStatus

1.3.6.1.3.83.1.6.4.1.2.30

Integer

4

docsDevFilterIpControl

1.3.6.1.3.83.1.6.4.1.3.30

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.3.83.1.6.4.1.4.30

Integer32

0

docsDevFilterIpDirection

1.3.6.1.3.83.1.6.4.1.5.30

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.3.83.1.6.4.1.6.30

Integer

2

docsDevFilterIpProtocol

1.3.6.1.3.83.1.6.4.1.11.30

Integer

6

docsDevFilterIpSourcePortLow

1.3.6.1.3.83.1.6.4.1.12.30

Integer

0

docsDevFilterIpSourcePortHigh

1.3.6.1.3.83.1.6.4.1.13.30

Integer

65535

docsDevFilterIpDestPortLow

1.3.6.1.3.83.1.6.4.1.14.30

Integer

137

docsDevFilterIpDestPortHigh

1.3.6.1.3.83.1.6.4.1.15.30

Integer

139

 

docsDevFilterIpStatus

1.3.6.1.3.83.1.6.4.1.2.40

Integer

4

docsDevFilterIpControl

1.3.6.1.3.83.1.6.4.1.3.40

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.3.83.1.6.4.1.4.40

Integer32

0

docsDevFilterIpDirection

1.3.6.1.3.83.1.6.4.1.5.40

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.3.83.1.6.4.1.6.40

Integer

2

docsDevFilterIpProtocol

1.3.6.1.3.83.1.6.4.1.11.40

Integer

6

docsDevFilterIpSourcePortLow

1.3.6.1.3.83.1.6.4.1.12.40

Integer

137

docsDevFilterIpSourcePortHigh

1.3.6.1.3.83.1.6.4.1.13.40

Integer

139

docsDevFilterIpDestPortLow

1.3.6.1.3.83.1.6.4.1.14.40

Integer

0

docsDevFilterIpDestPortHigh

1.3.6.1.3.83.1.6.4.1.15.40

Integer

65535

Step 4

Set up filters 50 and 60 to prevent the DHCP server operating in the home network from observing or injecting inappropriate DHCP traffic into the MSO network. All UDP-based NetBIOS traffic for a bootp client or server (port 67 or 68) is discarded. Set the following MIBs to the indicated values:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpStatus

1.3.6.1.3.83.1.6.4.1.2.50

Integer

4

docsDevFilterIpControl

1.3.6.1.3.83.1.6.4.1.3.50

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.3.83.1.6.4.1.4.50

Integer32

1

docsDevFilterIpDirection

1.3.6.1.3.83.1.6.4.1.5.50

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.3.83.1.6.4.1.6.50

Integer

2

docsDevFilterIpProtocol

1.3.6.1.3.83.1.6.4.1.11.50

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.3.83.1.6.4.1.12.50

Integer

68

docsDevFilterIpSourcePortHigh

1.3.6.1.3.83.1.6.4.1.13.50

Integer

68

docsDevFilterIpDestPortLow

1.3.6.1.3.83.1.6.4.1.14.50

Integer

67

docsDevFilterIpDestPortHigh

1.3.6.1.3.83.1.6.4.1.15.50

Integer

67

 

docsDevFilterIpStatus

1.3.6.1.3.83.1.6.4.1.2.60

Integer

4

docsDevFilterIpControl

1.3.6.1.3.83.1.6.4.1.3.60

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.3.83.1.6.4.1.4.60

Integer32

2

docsDevFilterIpDirection

1.3.6.1.3.83.1.6.4.1.5.60

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.3.83.1.6.4.1.6.60

Integer

2

docsDevFilterIpProtocol

1.3.6.1.3.83.1.6.4.1.11.60

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.3.83.1.6.4.1.12.60

Integer

67

docsDevFilterIpSourcePortHigh

1.3.6.1.3.83.1.6.4.1.13.60

Integer

67

docsDevFilterIpDestPortLow

1.3.6.1.3.83.1.6.4.1.14.60

Integer

68

docsDevFilterIpDestPortHigh

1.3.6.1.3.83.1.6.4.1.15.60

Integer

68

 

 

 

To create an IP filter (for Cisco IOS Release 12.1 T), follow this procedure.

Field

Description

Usage Notes

Step 1

Set the following MIB to the indicated value:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpDefault

1.3.6.1.2.1.69.1.6.3.0

Integer

2

Note: The default action is to accept all IP traffic.

Step 2

Set up filters 10 and 20 to discard UDP-based NetBIOS traffic. All UDP-based NetBIOS traffic (client or server) is discarded if the source or destination port is 137, 138, or 139. Set the following MIBs to the indicated values:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpStatus

1.3.6.1.2.1.69.1.6.4.1.2.10

Integer

4

docsDevFilterIpControl

1.3.6.1.2.1.69.1.6.4.1.3.10

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.2.1.69.1.6.4.1.4.10

Integer32

0

docsDevFilterIpDirection

1.3.6.1.2.1.69.1.6.4.1.5.10

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.2.1.69.1.6.4.1.6.10

Integer

2

docsDevFilterIpProtocol

1.3.6.1.2.1.69.1.6.4.1.11.10

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.2.1.69.1.6.4.1.12.10

Integer

137

docsDevFilterIpSourcePortHigh

1.3.6.1.2.1.69.1.6.4.1.13.10

Integer

139

docsDevFilterIpDestPortLow

1.3.6.1.2.1.69.1.6.4.1.14.10

Integer

0

 docsDevFilterIpDestPortHigh

1.3.6.1.2.1.69.1.6.4.1.15.10

Integer

65535

 

docsDevFilterIpStatus

1.3.6.1.2.1.69.1.6.4.1.2.20

Integer

4

docsDevFilterIpControl

1.3.6.1.2.1.69.1.6.4.1.3.20

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.2.1.69.1.6.4.1.4.20

Integer32

0

docsDevFilterIpDirection

1.3.6.1.2.1.69.1.6.4.1.5.20

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.2.1.69.1.6.4.1.6.20

Integer

2

docsDevFilterIpProtocol

1.3.6.1.2.1.69.1.6.4.1.11.20

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.2.1.69.1.6.4.1.12.20

Integer

0

docsDevFilterIpSourcePortHigh

1.3.6.1.2.1.69.1.6.4.1.13.20

Integer

65535

docsDevFilterIpDestPortLow

1.3.6.1.2.1.69.1.6.4.1.14.20

Integer

137

docsDevFilterIpDestPortHigh

1.3.6.1.2.1.69.1.6.4.1.15.20

Integer

139

Step 3

Set up filters 30 and 40 to discard TCP-based NetBIOS traffic. Set the following MIBs to the indicated values:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpStatus

1.3.6.1.2.1.69.1.6.4.1.2.30

Integer

4

docsDevFilterIpControl

1.3.6.1.2.1.69.1.6.4.1.3.30

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.2.1.69.1.6.4.1.4.30

Integer32

0

docsDevFilterIpDirection

1.3.6.1.2.1.69.1.6.4.1.5.30

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.2.1.69.1.6.4.1.6.30

Integer

2

docsDevFilterIpProtocol

1.3.6.1.2.1.69.1.6.4.1.11.30

Integer

6

docsDevFilterIpSourcePortLow

1.3.6.1.2.1.69.1.6.4.1.12.30

Integer

0

docsDevFilterIpSourcePortHigh

1.3.6.1.2.1.69.1.6.4.1.13.30

Integer

65535

docsDevFilterIpDestPortLow

1.3.6.1.2.1.69.1.6.4.1.14.30

Integer

137

docsDevFilterIpDestPortHigh

1.3.6.1.2.1.69.1.6.4.1.15.30

Integer

139

 

docsDevFilterIpStatus

1.3.6.1.2.1.69.1.6.4.1.2.40

Integer

4

docsDevFilterIpControl

1.3.6.1.2.1.69.1.6.4.1.3.40

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.2.1.69.1.6.4.1.4.40

Integer32

0

docsDevFilterIpDirection

1.3.6.1.2.1.69.1.6.4.1.5.40

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.2.1.69.1.6.4.1.6.40

Integer

2

docsDevFilterIpProtocol

1.3.6.1.2.1.69.1.6.4.1.11.40

Integer

6

docsDevFilterIpSourcePortLow

1.3.6.1.2.1.69.1.6.4.1.12.40

Integer

137

docsDevFilterIpSourcePortHigh

1.3.6.1.2.1.69.1.6.4.1.13.40

Integer

139

docsDevFilterIpDestPortLow

1.3.6.1.2.1.69.1.6.4.1.14.40

Integer

0

docsDevFilterIpDestPortHigh

1.3.6.1.2.1.69.1.6.4.1.15.40

Integer

65535

Step 4

Set up filters 50 and 60 to prevent the DHCP server operating in the home network from observing or injecting inappropriate DHCP traffic into the MSO network. All UDP-based NetBIOS traffic for a bootp client or server (port 67 or 68) is discarded. Set the following MIBs to the indicated values:

DOCSIS MIB Name

Object ID

Type

Value

docsDevFilterIpStatus

1.3.6.1.2.1.69.1.6.4.1.2.50

Integer

4

docsDevFilterIpControl

1.3.6.1.2.1.69.1.6.4.1.3.50

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.2.1.69.1.6.4.1.4.50

Integer32

1

docsDevFilterIpDirection

1.3.6.1.2.1.69.1.6.4.1.5.50

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.2.1.69.1.6.4.1.6.50

Integer

2

docsDevFilterIpProtocol

1.3.6.1.2.1.69.1.6.4.1.11.50

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.2.1.69.1.6.4.1.12.50

Integer

68

docsDevFilterIpSourcePortHigh

1.3.6.1.2.1.69.1.6.4.1.13.50

Integer

68

docsDevFilterIpDestPortLow

1.3.6.1.2.1.69.1.6.4.1.14.50

Integer

67

docsDevFilterIpDestPortHigh

1.3.6.1.2.1.69.1.6.4.1.15.50

Integer

67

 

docsDevFilterIpStatus

1.3.6.1.2.1.69.1.6.4.1.2.60

Integer

4

docsDevFilterIpControl

1.3.6.1.2.1.69.1.6.4.1.3.60

Integer

1

docsDevFilterIpIfIndex

1.3.6.1.2.1.69.1.6.4.1.4.60

Integer32

2

docsDevFilterIpDirection

1.3.6.1.2.1.69.1.6.4.1.5.60

Integer

3

docsDevFilterIpBroadcast

1.3.6.1.2.1.69.1.6.4.1.6.60

Integer

2

docsDevFilterIpProtocol

1.3.6.1.2.1.69.1.6.4.1.11.60

Integer

17

docsDevFilterIpSourcePortLow

1.3.6.1.2.1.69.1.6.4.1.12.60

Integer

67

docsDevFilterIpSourcePortHigh

1.3.6.1.2.1.69.1.6.4.1.13.60

Integer

67

docsDevFilterIpDestPortLow

1.3.6.1.2.1.69.1.6.4.1.14.60

Integer

68

docsDevFilterIpDestPortHigh

1.3.6.1.2.1.69.1.6.4.1.15.60

Integer

68

 

Related Topics

SNMP