Administrator Guide

Figure 137. Interface Index Number Assigned to FortyGigE 0/4 Port
In this example, if you start from the least significant bit on the right:
• The first 14 bits (00001000000010) identify a line card.
• The next 4 bits (1001) identify a 40-Gigabit Ethernet interface.
• The next 12 bits (000011000100) identify slot 0 and port 4.
• The next bit (0) identifies a physical interface.
• The last bit is always 0, which means that it is unused.
NOTE: The interface index does not change if the interface reloads or fails over.
If you know the interface index, use the following commands to find the interface number.
DellEMC ~ $ snmpwalk -v 2c -c public 10.16.206.127 .1.3.6.1.2.1.2.2.1.2 | grep 2097156
IF-MIB::ifDescr.2097156 = STRING: TenGigabitEthernet 1/1
DellEMC ~ $ snmpwalk -v 2c -c public 10.16.206.127 .1.3.6.1.2.1.31.1.1.1.1 | grep 2097156
IF-MIB::ifName.2097156 = STRING: TenGigabitEthernet 1/1
You can use the show interfaces command to view the interface index.
Dell#show interface fortyGigE 0/4
fortyGigE 0/4 is down, line protocol is down
Description: if_0/4 | if_forty
Hardware is DellForce10Eth, address is 74:86:7a:ff:6f:08
Current address is 74:86:7a:ff:6f:08
Pluggable media not present
Interface index is 2097156
[output omitted]
Monitoring BGP sessions via SNMP
This section covers the monitoring of BGP sessions using SNMP.
BGP SNMP support for non-default VRF uses a SNMP context to distinguish multiple BGP VRF instances within a single BGP process.
SNMP context is a repository of management information that can be accessed through the SNMP agent. SNMP supports multiple
contexts in a device. SNMPv3 has a context name field in its PDU, which automatically allows the context name field to be mapped to a
particular VRF instance without having to be mapped to a community map. SNMPv2c context has to be mapped to a community map. A
new CLI command, snmp context, under BGP context, has been introduced to perform this function.
To map the context to a VRF instance for SNMPv2c, follow these steps:
1. Create a community and map a VRF to it. Create a context and map the context and community, to a community map.
• sho run snmp
• snmp-server community public ro
• snmp-server community public ro
• snmp-server community vrf1 ro
• snmp-server community vrf2 ro
• snmp-server context context1
• snmp-server context context2
• snmp mib community-map vrf1 context context1
• snmp mib community-map vrf1 context context2
2. Configure snmp context under the VRF instances.
892
Simple Network Management Protocol (SNMP)