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NAME

snmpwalk - communicates with a network entity using SNMP GET Next Requests.

SYNOPSIS

snmpwalk [-p <port>][-T <timeout>][-R <retries>] host community [variable-name]

DESCRIPTION

Snmpwalk is an SNMP application that uses GET NEXT Requests to query for a tree of information about a network entity.

The host specification may be either a host name or an internet address specified in "dot notation"

The community specifies the community name for the transaction with the remote system.

A variable may also be given on the command line. This variable specifies which portion of the object identifier space will be searched using GET NEXT Requests. All variables in the subtree below the given variable are queried and their values presented to the user. Each variable name is given in the format specified in variables(5) .

If the "variable-name" argument is not present, snmpwalk will search the whole Internet MIB.

For example

snmpwalk netdev-kbox.cc.cmu.edu public system

will retrieve the variables sysDescr.0 and sysObjectID.0 and sysUpTime.0:

Name: system.sysDescr.0
OCTET STRING- (ascii):    Kinetics FastPath2

Name: system.sysObjectID.0
OBJECT IDENTIFIER: .iso.org.dod.internet.private.enterprises.CMU.sysID.CMU-KIP

Name: system.sysUpTime.0
Timeticks: (2291082) 6:21:50

If the network entity has an error processing the request packet, an error packet will be returned and a message will be shown, helping to pinpoint why the request was malformed.

If the tree search causes attempts to search beyond the end of the MIB, a message will be displayed:

End of MIB.

Adding a "-d" to the argument list will cause the application to dump input and output packets.

OPTIONS

-p <port>
The port at the destination host to be connected. The default port is 161.
-T <timeout>
The initial timeout. Note: the timeout is increased after every try. The default value is 300 ms.
-R <retries>
The number of retries. The default value is 6 tries.

COMMUNITY ARGUMENT

The agent and applications are all SNMPv1/SNMPv2c/SNMPv2u compatible. The version is that the application will use is selected by inspecting the first character of the community string provided to the application, as follows:
o
if the first character of the community string is a "+" then the SNMPv2c (community-based SNMPv2 as specified in RFC 1901) is used (the remainder of the community string is used as the actual community string);
o
if the first character of the community string is a "/" then the SNMPv2u (User-based security model) is used (see the note below for more details);
o
all other community strings select SNMPv1.

A community string that begins with a slash selects the SNMPv2u protocol. The "community" string is parsed to build the parameters for the communication. The format of the string is:    /userName/[authKey]/[privKey]/[contextSelector]
Trailing slashes may be omitted. Both authKey and privKey may be specified as hex or as a human readable password. To specify a hex key, the key must begin with "0x" and be followed by exactly 32 hex digits (to form a 16 octet key). If a human readable password is entered, the password is passed through the "password to key algorithm" to generate the 16 octet key. The password to key algorithm is specified in the "User-Based Security Model for SNMPv2" RFC.

A "+" or "/" character may not start a SNMPv1 community string and may not be contained within any SNMPv2 parameters (this is an *implementation* restriction).

Some "community" string examples: /joe            -- qos=noAuth/noPriv, context="", userName="joe"

/boneless/chicken/ranch -- qos=auth/priv, context="", userName="boneless"
            authKey=pw2key("chicken"), privKey=pw2key("ranch")
            *note* privacy not supported, trying this will generate
            a UnsupportedQoS report.

/maplesyrup/sugarbush//other
           -- qos=auth/noPriv, context="other", userName="maplesyrup"
            authKey=pw2key("sugarbush",agentID)

/glenn/0x4ca25023b00a6689ef21cb1b6fa9cb0e
           -- qos=auth/noPriv, context="", userName="glenn"
            authKey=4ca25023b00a6689ef21cb1b6fa9cb0e
            (the authKey is keyed using an agentID)

+public            -- SNMPv2c using public as the community string

public            -- SNMPv1 using public as the community string

SEE ALSO

variables(5) , RFC 1065, RFC 1066, RFC 1067

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