What Is SNMP walking

Hello , I am New To Networking Field ALthough I have heard about SNMP walking.But Dont Know Eaxtly what Is it Can you explain me what is SNMP walking? And Other Relevent Details Related To it Thanks in Advance

The SNMP application snmpwalk retrieves SNMP GETNEXT requests to query a network entity for a tree of information. The command syntax for SNMP is as follows:

snmpwalk [APPLICATION OPTIONS] [COMMON OPTIONS] [OID]

The OID may be given on the command line, which specifies which portion of the object identifier space is to be searched using GETNEXT requests. If the OID is not specified, snmpwalk searches the entire root.

snmpwalk -- Fetch all the SNMP objects from an agent

Description
array snmpwalk ( string hostname, string community, string object_id [, int timeout [, int retries]])

Returns an array of SNMP object values starting from the object_id as root and FALSE on error.

snmpwalk() function is used to read all the values from an SNMP agent specified by the hostname. Community specifies the read community for that agent. A NULL object_id is taken as the root of the SNMP objects tree and all objects under that tree are returned as an array. If object_id is specified, all the SNMP objects below that object_id are returned.

Code:

---

<?php
$a = snmpwalk("127.0.0.1", "public", "");
?>

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Above function call would return all the SNMP objects from the SNMP agent running on localhost. One can step through the values with a loop

Code:

---

<?php
for ($i=0; $i < count($a); $i++) {
    echo $a[$i];
}
?>

---

The snmpwalk utility is an SNMP application that uses SNMP GETNEXT requests to query a network entity for a tree of information.

You can specify an object identifier (OID) on the command line. This OID specifies which portion of the object identifier space will be searched using GETNEXT requests. All variables in the subtree below the specified OID are queried and their values returned. Each variable name must be entered in the format specified in snmp_variables(4).

If no OID argument is present, snmpwalk searches MIB-2. If the network entity has an error processing the request packet, an error packet is returned and a message displayed, indicating t the way in which the request was malformed.

If the tree search causes attempts to search beyond the end of the MIB, the message “End of MIB” is displayed.