BRIDGE-MIB on Cisco Router

Answered Question
Oct 15th, 2008

Hi everyone,

I have question about BRIDGE-MIB on Cisco Router.

I tested this on both

Cisco 3825 12.4(18) with 16 Port 10BaseT/100BaseTX EtherSwitch (NM-16ESW)

Catalyst 4948 12.2(20)EWA4

I configured access ports for vlan 1, vlan 20 and SVI ports for vlan 1 and 20 as interface vlan on Cisco 3825 and Catalyst 4948. The result of my investigation are as follows:

==========

Test 1:

community string configured on Cisco 3825 is "public"

community string configured on Catalyst 4948 is "public"

MIB browsing (same as snmpwalk) for ".1.3.6.1.2.1.17" (dot1dBridge) for vlan 1 with "public" as community because this SNMP polling against to vlan 1.

Result:

Cisco 3825 supports only "1.3.6.1.2.1.17.1" (dot1dBridge.dot1dBase), not support full BRIDGE-MIB in other words Cisco 3825 does not support all MIB objects under .1.3.6.1.2.1.17 (dot1dBridge), such as "1.3.6.1.2.1.17.4" and so on. And returned values from Cisco 3825 for "1.3.6.1.2.1.17.1" (dot1dBridge.dot1dBase) seem like incorrect.

Catalyst 4948 supports full BRIDGE-MIB in other words all MIB objects under .1.3.6.1.2.1.17 (dot1dBridge), and all returned values from Catalyst 4948 seem like correct.

==========

Test 2:

community string configured on Cisco 3825 is "public"

community string configured on Catalyst 4948 is "public"

MIB browsing (same as snmpwalk) for "1.3.6.1.2.1.17.1" (dot1dBridge.dot1dBase) for vlan 20 with "[email protected]" as community because this SNMP polling against to vlan 20.

Result:

Cisco 3825 did not respond this SNMP polling and generated AuthenticationFailure TRAP.

Catalyst 4948 responded this SNMP polling and of course did not generate AuthenticationFailure TRAP.

==========

Test 3:

community string "[email protected]" added into Cisco 3825.

MIB browsing (same as snmpwalk) for "1.3.6.1.2.1.17.1" (dot1dBridge.dot1dBase) for vlan 20 with "[email protected]" as community because this SNMP polling against to vlan 20.

Result:

C3825 responded this SNMP polling without generating AuthenticationFailure TRAP. However as same as the result of Test 1, returned values from Cisco 3825 for "1.3.6.1.2.1.17.1 (dot1dBridge.dot1dBase) for seem like incorrect.

==========

Based on the result of investigation, I guess this symptom caused by either

Router IOS defect

or

Router restriction, for example, Router does not support BRIDGE-MIB object even if "show snmp mib" displayed dot1dxxxxxx mib objects as same as output on Catalyst 4948.

I searched Bug Navigator, but I could not find any related DDTS.

I understand I should open SR to TAC for further investigation, however if you have any idea or experience, I would like to know about it.

Your information would be appreciated.

Best regards,

Shinichi

I have this problem too.
0 votes
Correct Answer by Joe Clarke about 8 years 1 month ago

The bug has not been fixed, and there is no ETA on when (or if) it will be fixed. It affects all versions of 12.4 and 12.4T. The details are as follows:

Symptom:

A 2600/3600 with NM-16ESW acts as a switch. CiscoWorks UserTracking will poll all switches to find all end-hosts connected to the network.

Since this device does not support the BRIDGE-MIB, User Tracking cannot find the end-hosts.

Conditions:

2600/3600 with NM-16ESW module.

Workaround:

No workaround is available.

Further Problem Description:

Once the BRIDGE-MIB is populated for this module, Campus Manager needs to be changed to treath this device/module as a switch. The DE-team already confirmed they will do this as soon as this feature is implemented in IOS itself.

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Joe Clarke Wed, 10/15/2008 - 08:30

You are correct that the routers do not support the community string indexing for the BRIDGE-MIB. The bug is CSCsb46470.

snakayama Wed, 10/15/2008 - 17:36

Hi,

Thank you very much for your reply.

I searched CSCsb46470 on Bug Toolkit, but I can not see the detail of CSCsb46470 due to this is only available to Cisco employees.

"Information contained within bug ID CSCsb46470 is only available to Cisco employees". is displayed.

So could you please let me know the detail of CSCsb46470 ? If so. I would like to know such as,

Symptoms

Conditions

Workaround

1st Found-In and Known Affected Versions

Fixed-In

Best regards,

Correct Answer
Joe Clarke Wed, 10/15/2008 - 20:15

The bug has not been fixed, and there is no ETA on when (or if) it will be fixed. It affects all versions of 12.4 and 12.4T. The details are as follows:

Symptom:

A 2600/3600 with NM-16ESW acts as a switch. CiscoWorks UserTracking will poll all switches to find all end-hosts connected to the network.

Since this device does not support the BRIDGE-MIB, User Tracking cannot find the end-hosts.

Conditions:

2600/3600 with NM-16ESW module.

Workaround:

No workaround is available.

Further Problem Description:

Once the BRIDGE-MIB is populated for this module, Campus Manager needs to be changed to treath this device/module as a switch. The DE-team already confirmed they will do this as soon as this feature is implemented in IOS itself.

snakayama Wed, 10/15/2008 - 20:45

Hi,

Thank you very much for your reply and useful information !

I understand it.

Best regards,

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