SNMP support for PFC, ECN, and CoS ingress packet drop accounting

SNMP support that helps to account for the packets that are dropped because of ingress port congestion. We can view and export the error counters data for explicit congestion notification (ECN), ingress drops, and priority-based flow control (PFC) using the following commands: 

• show snmp mib walk ifJnxTable 
• show snmp mib walk jnxCosPfcPriorityTable