Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 895

Fetch Dynamic MAC Entries using SNMP Dell Networking supports the RFC 1493 dot1d table for the default VLAN and the dot1q table for all other VLANs. NOTE: The 802.1q Q-BRIDGE MIB defines VLANs regarding 802.1d, as 802.1d itself does not define them. As a switchport must belong a VLAN (the default VLAN or a configured VLAN), all MAC address learned on a switchport are associated with a VLAN. For this reason, the Q-Bridge MIB is used for MAC address query. Moreover, specific to MAC address query, the MAC address indexes dot1dTpFdbTable only for a single forwarding database, while dot1qTpFdbTable has two indices - VLAN ID and MAC address - to allow for multiple forwarding databases and considering that the same MAC address is learned on multiple VLANs. The VLAN ID is added as the first index so that MAC addresses are read by the VLAN, sorted lexicographically. The MAC address is part of the OID instance, so in this case, lexicographic order is according to the most significant octet. Table 86. MIB Objects for Fetching Dynamic MAC Entries in the Forwarding Database MIB Object OID MIB dot1dTpFdbTable .1.3.6.1.2.1.17.4.3 Q-BRIDGE MIB dot1qTpFdbTable .1.3.6.1.2.1.17.7.1.2. 2 Q-BRIDGE MIB dot3aCurAggFdb Table .1.3.6.1.4.1.6027.3.2. 1.1.5 F10-LINK-AGGREGATION MIB Description List the learned unicast MAC addresses on the default VLAN. List the learned unicast MAC addresses on non-default VLANs. List the learned MAC addresses of aggregated links (LAG). In the following example, R1 has one dynamic MAC address, learned off of port TenGigabitEthernet 1/21, which a member of the default VLAN, VLAN 1. The SNMP walk returns the values for dot1dTpFdbAddress, dot1dTpFdbPort, and dot1dTpFdbStatus. Each object is comprised of an OID concatenated with an instance number. In the case of these objects, the instance number is the decimal equivalent of the MAC address; derive the instance number by converting each hex pair to its decimal equivalent. For example, the decimal equivalent of E8 is 232, and so the instance number for MAC address 00:01:e8:06:95:ac is. 0.1.232.6.149.172. The value of dot1dTpFdbPort is the port number of the port off which the system learns the MAC address. In this case, of TenGigabitEthernet 1/21, the manager returns the integer 118. Example of Fetching MAC Addresses Learned on the Default VLAN Using SNMP MAC Addresses on Force10 System R1_E600#show mac-address-table VlanId Mac Address Type Interface State 1 00:01:e8:06:95:ac Dynamic Te 1/21 Active Query from Management Station >snmpwalk -v 2c -c techpubs 10.11.131.162 .1.3.6.1.2.1.17.4.3.1 SNMPv2-SMI::mib-2.17.4.3.1.1.0.1.232.6.149.172 = Hex-STRING: 00 01 E8 06 95 AC Example of Fetching MAC Addresses Learned on a Non-default VLAN Using SNMP In the following example, TenGigabitEthernet 1/21 is moved to VLAN 1000, a non-default VLAN. To fetch the MAC addresses learned on non-default VLANs, use the object dot1qTpFdbTable. The instance number is the VLAN number concatenated with the decimal conversion of the MAC address. MAC Addresses on Force10 System------------ R1_E600#show mac-address-table VlanId Mac Address Type Interface State 1000 00:01:e8:06:95:ac Dynamic Te 1/21 Active Query from Management Station >snmpwalk -v 2c -c techpubs 10.11.131.162 .1.3.6.1.2.1.17.7.1.2.2.1 Simple Network Management Protocol (SNMP) 895