Interface up down notification

Remember the status identifiers are for if nodes/interfaces are responding or not, or if they are having issues responding..  A "Warning" or "Unknown" status isn't for anything else other than the polling status of an node/interface.  They don't report the health or hardware error status of a node/interface other than showing Up (they respond) or  Down (no response after x amount of time).  They are simply an indication of the Up/Down Status or an in between status due to Packet Loss, or inability to poll. 

From what I was reading it seems you are or were thinking the Warning and Unknown statuses are reporting something to you other than the availability of the Node or Interface and its ability to respond to a ICMP or SNMP packet.

When a node/interface is responding and up you can get some error and buffer dropping statistics from SNMP and they can show an issue on the Node/Interface or something coming from the Line connected to the node/interface causing an issue, but this will not take a node/interface out of Up (green) status while reporting these errors unless the node/interface it self stops responding to these request for information. 

Remember the status identifiers are for if nodes/interfaces are responding or not, or if they are having issues responding..  A "Warning" or "Unknown" status isn't for anything else other than the polling status of an node/interface.  They don't report the health or hardware error status of a node/interface other than showing Up (they respond) or  Down (no response after x amount of time).  They are simply an indication of the Up/Down Status or an in between status due to Packet Loss, or inability to poll. 

From what I was reading it seems you are or were thinking the Warning and Unknown statuses are reporting something to you other than the availability of the Node or Interface and its ability to respond to a ICMP or SNMP packet.

When a node/interface is responding and up you can get some error and buffer dropping statistics from SNMP and they can show an issue on the Node/Interface or something coming from the Line connected to the node/interface causing an issue, but this will not take a node/interface out of Up (green) status while reporting these errors unless the node/interface it self stops responding to these request for information.