SNMP Community String Indexing

Transcription

1 SNMP Community String Indexing Document ID: Contents Introduction Prerequisites Requirements Components Used Conventions Community String Indexing The BRIDGE MIB Procedure Related Information Introduction This document describes how to use Simple Network Management Protocol (SNMP) community string indexing on Catalyst switches. Prerequisites Requirements There are no specific requirements for this document. Components Used This document applies to all Catalyst switches that run regular Catalyst OS or Catalyst IOS which support the BRIDGE MIB. The example in this document usas a Catalyst 5500 that runs 5.5(4) code. The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command. Conventions Refer to Cisco Technical Tips Conventions for more information on document conventions. Community String Indexing Some standard MIBs assume that a particular SNMP entity contains only one instance of the MIB. Thus, the standard MIB does not have any index that allows you to directly access an instance of the MIB. In these cases, a community string indexing is provided to access each instance of the standard MIB. The syntax is [community string]@[instance number]. For example, the Catalyst switch includes one instance of the standard BRIDGE MIB for each VLAN in the switch. If the read only community string is public and the read write community string is private, you can use public@25 to read the BRIDGE MIB for VLAN 25 and use private@33 to read and write the BRIDGE MIB for VLAN 33. If just public or private is used, the BRIDGE MIB for VLAN 1 is accessed.

2 Traps sent from a MIB that is indexed by community string also indicate which instance of the MIB it corresponds to by using community string indexing. For example, a newroot trap from the BRIDGE MIB for VLAN 25 would have a community string of public@25 (assuming the read only community string is public). Note: Community string indexing does not affect access to MIBs that have only one instance. Thus, public@25 can be used to access RFC1213 MIB at the same time the BRIDGE MIB for VLAN 25 is accessed. Another example for the Catalyst switches is the SNMP REPEATER MIB. Use [community string]@[module number/port number] to access this MIB for a particular repeater in the Catalyst switch. For example, if the read only community string is public, you could use public@3/1 to read the SNMP REPEATER MIB for the repeater attached to port 1 on module 3. The BRIDGE MIB One MIB that uses community string indexing is the BRIDGE MIB. Procedure Complete these steps in order to get dynamic CAM entries. This example uses the Catalyst For comparison, gather the output from the show cam dynamic command. The Catalyst code that runs in this example is release 5.5(4): CAT5500 (enable) show cam dynamic * = Static Entry. + = Permanent Entry. # = System Entry. R = Router Entry. X = Port Security Entry VLAN Dest MAC/Route Des [CoS] Destination Ports or VCs / [Protocol Type] 1 00 e0 b /23 24 [ALL] c 01 a4 3e 11/23 24 [ALL] c /2 [ALL] ca 15 9d 08 7/2 [ALL] e /2 [ALL] c 7/5 [ALL] c 31 d0 a5 11/5 [ALL] c f0 1b 7a 7/11 [ALL] c 01 b8 aa 11/23 24 [ALL] f6 5f /1 [ALL] c /2 [ALL] c 7/6 [ALL] 1 00 d /2 [ALL] b4 fe 81 11/7 [ALL] e4 af 00 11/23 24 [ALL] c f4 eb 7a 7/2 [ALL] d1 9f 6c 00 11/23 24 [ALL] c 34 a1 0b 11/23 24 [ALL] 1 00 d0 02 0c 17 ff 7/2 [ALL] f /7 [ALL] f 78 bb fd 11/23 24 [ALL] f 78 bb ff 11/23 24 [ALL] f 78 bb fe 11/23 24 [ALL] c 2c 83 cd 7/2 [ALL] b4 fe 81 11/7 [ALL] c /23 24 [ALL] c 01 1c 5a 11/23 24 [ALL] f2 fc 38 c0 11/23 24 [ALL] b4 fe 81 11/7 [ALL]

3 /8 [ALL] Total Matching CAM Entries Displayed = 30 Get the MAC address table dot1dtpfdbaddress ( ). snmpwalk public iso = Hex C 34 A1 0B.iso = Hex C iso = Hex C iso = Hex C F0 1B 7A.iso = Hex C F4 EB 7A.iso = Hex B4 FE 81.iso = Hex E4 AF 00.iso = Hex iso = Hex E iso = Hex B F6 5A 44.iso = Hex C 2C 83 CD.iso = Hex F6 5F iso = Hex C.iso = Hex C.iso = Hex F2 FC 38 C0.iso = Hex CA 15 9D 08.iso = Hex F 78 BB FD.iso = Hex F 78 BB FE.iso = Hex F 78 BB FF.iso = Hex D1 9F 6C 00.iso = Hex C 01 1C 5A.iso = Hex C iso = Hex C 01 A4 3E.iso = Hex C 01 B8 AA.iso = Hex F iso = Hex 00 D0 02 0C 17 FF.iso = Hex 00 D iso = Hex 00 E0 B Get the bridge port number, dot1dtpfdbport ( ). snmpwalk public iso = 844.iso = 386.iso = 386.iso = 395.iso = 386.iso = 647.iso = 844.iso = 392.iso = 386.iso = 844.iso = 386.iso = 385.iso = 390.iso = 389.iso = 844.iso = 386.iso = 844.iso = 844.iso = 844.iso = 844.iso = 844.iso = 844.iso = 844.iso = 844.iso = 391.iso = 386.iso = 386.iso = 844

4 Get the bridge port to ifindex mapping, dot1dbaseportifindex ( ). snmpwalk public iso = 288.iso = 289.iso = 291.iso = 292.iso = 294.iso = 295.iso = 296.iso = 9.iso = 11.iso = 12.iso = 13.iso = 14.iso = 15.iso = 16.iso = 17.iso = 18.iso = 19.iso = 20.iso = 21.iso = 22.iso = 23.iso = 24.iso = 25.iso = 26.iso = 27.iso = 28.iso = 29.iso = 30.iso = 31.iso = 297.iso = 298.iso = 299.iso = 300.iso = 301.iso = 302.iso = 303.iso = 304.iso = 305.iso = 307.iso = 308.iso = 34.iso = 459.iso = 460.iso = 461.iso = 462.iso = 463.iso = 464.iso = 465.iso = 466.iso = 467.iso = 468.iso = 469.iso = 470.iso = 375.iso = 376.iso = 377.iso = 378.iso = 380.iso = 381.iso = 382.iso = 383.iso = 384

5 4..iso = 385.iso = 386.iso = 387.iso = 388.iso = 389.iso = 390.iso = 391.iso = 392.iso = 393.iso = 394.iso = 395.iso = Walk the ifname ( ). snmpwalk public iso = "sc0" Hex iso = "sl0" Hex 73 6C 30.iso = "VLAN 1".iso = "VLAN 1002".iso = "VLAN 1004".iso = "VLAN 1005".iso = "VLAN 1003".iso = "4/1" Hex 34 2F 31.iso = "4/2" Hex 34 2F 32.iso = "4/3" Hex 34 2F 33.iso = "4/4" Hex 34 2F 34.iso = "4/5" Hex 34 2F 35.iso = "4/6" Hex 34 2F 36.iso = "4/7" Hex 34 2F 37.iso = "4/8" Hex 34 2F 38.iso = "4/9" Hex 34 2F 39.iso = "4/10" Hex 34 2F iso = "4/11" Hex 34 2F iso = "4/12" Hex 34 2F iso = "4/13" Hex 34 2F iso = "4/14" Hex 34 2F iso = "4/15" Hex 34 2F iso = "4/16" Hex 34 2F iso = "4/17" Hex 34 2F iso = "4/18" Hex 34 2F iso = "4/19" Hex 34 2F iso = "4/20" Hex 34 2F iso = "4/21" Hex 34 2F iso = "4/22" Hex 34 2F iso = "4/23" Hex 34 2F iso = "4/24" Hex 34 2F iso = "3/1" Hex 33 2F 31.iso = "3/2" Hex 33 2F 32.iso = "3/3" Hex 33 2F 33.iso = "3/4" Hex 33 2F 34.iso = "3/5" Hex 33 2F 35.iso = "3/6" Hex 33 2F 36.iso = "3/7" Hex 33 2F 37.iso = "3/8" Hex 33 2F 38.iso = "3/9" Hex 33 2F 39.iso = "7/1" Hex 37 2F 31.iso = "7/2" Hex 37 2F 32.iso = "7/3" Hex 37 2F 33.iso = "7/4" Hex 37 2F 34.iso = "7/5" Hex 37 2F 35.iso = "7/6" Hex 37 2F 36.iso = "7/7" Hex 37 2F 37.iso = "7/8" Hex 37 2F 38.iso = "7/9" Hex 37 2F 39.iso = "7/10" Hex 37 2F iso = "7/11" Hex 37 2F 31 31

6 .iso = "7/12" Hex 37 2F iso = "11/1" Hex F 31.iso = "11/2" Hex F 32.iso = "11/3" Hex F 33.iso = "11/4" Hex F 34.iso = "11/5" Hex F 35.iso = "11/6" Hex F 36.iso = "11/7" Hex F 37.iso = "11/8" Hex F 38.iso = "11/9" Hex F 39.iso = "11/10".iso = "11/11".iso = "11/12".iso = "11/13".iso = "11/14".iso = "11/15".iso = "11/16".iso = "11/17".iso = "11/18".iso = "11/19".iso = "11/20".iso = "11/21".iso = "11/22".iso = "11/23".iso = "11/24".iso = "VLAN 100".iso = "VLAN 2".iso = "VLAN 32".iso = "VLAN 200".iso = "VLAN 3".iso = "VLAN 284".iso = "VLAN 66".iso = "VLAN 22".iso = "VLAN 4".iso = "VLAN 5".iso = "VLAN 300".iso = "VLAN 400".iso = "VLAN 88".iso = "VLAN 89".iso = "VLAN 99".iso = "VLAN 30".iso = "VLAN 999".iso = "VLAN 20".iso = "VLAN 40".iso = "9/1" Hex 39 2F 31.iso = "9/2" Hex 39 2F 32.iso = "9/3" Hex 39 2F 33.iso = "9/4" Hex 39 2F 34.iso = "9/5" Hex 39 2F 35.iso = "9/6" Hex 39 2F 36.iso = "9/7" Hex 39 2F 37.iso = "9/8" Hex 39 2F 38.iso = "9/9" Hex 39 2F 39.iso = "9/10" Hex 39 2F iso = "9/11" Hex 39 2F iso = "9/12" Hex 39 2F iso = "9/13" Hex 39 2F iso = "9/14" Hex 39 2F iso = "9/15" Hex 39 2F iso = "9/16" Hex 39 2F iso = "VLAN 21".iso = "VLAN 6".iso = "VLAN 7".iso = "10/1" Hex F 31.iso = "10/2" Hex F 32.iso = "10/3" Hex F 33

7 .iso = "10/4" Hex F 34.iso = "10/5" Hex F 35.iso = "10/6" Hex F 36.iso = "10/7" Hex F 37.iso = "10/8" Hex F 38.iso = "10/9" Hex F 39.iso = "10/10".iso = "10/11".iso = "10/12".iso = "VLAN 101".iso = "FEC 11/23 24".iso = "6/1" Hex 36 2F 31.iso = "NetFlow Interface" Now you can get the port information, for example: From Step 2:.iso = Hex C From Step 3:.iso = 386 This tells you that this MAC address ( C ) is from bridge port number 386. From Step 4: bridge port number 386 has an ifindex number 298.iso = 298 From Step 5: ifindex 298 corresponds to port 7/2.iso = "7/2" Hex 37 2F 32 Compare that with the output from the show cam dynamic command output in Step 1. You see a match for c /2 [ALL]. There are four VLANs in this example. The show cam dynamic output shows all the addresses, but snmpwalk only shows the ones in VLAN 1. You need to use community string indexing in order to get the entries for each of the VLANs. The syntax to use is: snmpwalk read_community@vlan_number VLAN 1 snmpwalk public@ = Hex B4 FE = Hex E4 AF = Hex = Hex F6 5F = Hex C = Hex C = Hex F2 FC 38 C = Hex F 78 BB FD = Hex F 78 BB FE = Hex F 78 BB FF = Hex D1 9F 4C = Hex E B = Hex C 01 1C 5A = Hex C 01 A4 3E = Hex 00 B C = Hex 00 E0 B VLAN 20: snmpwalk public@

8 = Hex C 31 D0 A = Hex B4 FE 81 VLAN 30: snmpwalk public@ = Hex B4 FE 81 VLAN 50: snmpwalk public@ = Hex B4 FE 81 Related Information SNMP Tech Notes Technical Support & Documentation Cisco Systems Contacts & Feedback Help Site Map Cisco Systems, Inc. All rights reserved. Terms & Conditions Privacy Statement Cookie Policy Trademarks of Cisco Systems, Inc. Updated: Oct 26, 2005 Document ID: 40367