purpose of MIB files in SNMP management stations

Discussion:

(too old to reply)

Martin T

2015-07-08 11:02:31 UTC

Hi,

it is obvious that MIB's are important for network management stations
as otherwise SNMP queries based on object names would not work. For
example:

$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
sysUpTimeInstance 2>/dev/null
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35
$

Another purpose of MIB's I can see is that they help to make sense of
returned values. For example here I don't have Cisco MIBs installed
and it is difficult to understand what "33939721.372808280" or
"68690115.642234535" means:

$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.33939721.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.724494656
= Counter32: 0
$

On the other hand, here I have required MIB databases installed and I
can easily see that those entries represent interface names:

$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 | head -3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$

Is there any additional purpose of MIB files in SNMP management stations?

thanks,
Martin

Stuart Kendrick

2015-07-08 11:54:00 UTC

Permalink

Speaking from an operational perspective, I myself would add to your list 'documentation' -- i.e., when I want to better understand what a variable and its values mean, I read the relevant section in the MIB files.

If they serve any other purpose, I would like to hear about it.

As an aside regarding terminology, I try to use the following lingo:

- Management Information Base (MIB): the collection of variables which the SNMP agent supports, typically chunked into discrete MIBs (e.g. IF-MIB, CISCO-STACK-MIB, LLDP-MIB ...)
[The fact that the "sum of all the MIBs" supported by an agent comprise its "MIB" bothers me ... not my idea of clear terminology.]

- MIB Files: the text files stored on the network management station which permit the station's SNMP libraries to perform the two functions you describe below. From an operational perspective, useful only to humans, for providing translation services between numbers and more-human-comprehensible-strings.

hth,

--sk

-----Original Message-----
From: Martin T [mailto:***@gmail.com]
Sent: Wednesday, July 08, 2015 4:03 AM
To: net-snmp-***@lists.sourceforge.net
Subject: purpose of MIB files in SNMP management stations

Hi,

it is obvious that MIB's are important for network management stations as otherwise SNMP queries based on object names would not work. For
example:

$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1 sysUpTimeInstance 2>/dev/null $ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $

Another purpose of MIB's I can see is that they help to make sense of returned values. For example here I don't have Cisco MIBs installed and it is difficult to understand what "33939721.372808280" or "68690115.642234535" means:

$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.33939721.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.724494656
= Counter32: 0
$

On the other hand, here I have required MIB databases installed and I can easily see that those entries represent interface names:

$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 | head -3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$

Is there any additional purpose of MIB files in SNMP management stations?

thanks,
Martin

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Martin T

2015-07-08 13:46:53 UTC

Permalink

Stuart,

yes, MIB files are a great way to look up for additional information
about a SNMP object. For example:

$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/*
ifName OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.

$

Is there any other purpose of MIB files in SNMP management stations?

regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to your list
'documentation' -- i.e., when I want to better understand what a variable
and its values mean, I read the relevant section in the MIB files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables which the
SNMP agent supports, typically chunked into discrete MIBs (e.g. IF-MIB,
CISCO-STACK-MIB, LLDP-MIB ...)
[The fact that the "sum of all the MIBs" supported by an agent comprise its
"MIB" bothers me ... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management station which
permit the station's SNMP libraries to perform the two functions you
describe below. From an operational perspective, useful only to humans, for
providing translation services between numbers and
more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management stations as
otherwise SNMP queries based on object names would not work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
sysUpTimeInstance 2>/dev/null $ snmpget -M /dir/that/does/not/exist -On -v
2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense of
returned values. For example here I don't have Cisco MIBs installed and it
is difficult to understand what "33939721.372808280" or "68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.33939721.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and I can
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 | head -3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management stations?
thanks,
Martin
------------------------------------------------------------------------------
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GigeNET's Cloud Solutions provide you with the tools and support that you
need to offload your IT needs and focus on growing your business.
Configured For All Businesses. Start Your Cloud Today.
https://www.gigenetcloud.com/
_______________________________________________
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Martin T

2015-07-08 13:53:03 UTC

Permalink

One additional purpose, which falls more or less under documentation,
is that MIB files give a fairly good overview what exactly a SNMP
agent on a device supports. On the other hand, this could be observed
with snmpwalking the device?

regards,
Martin

Post by Martin T
Stuart,
yes, MIB files are a great way to look up for additional information
$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/*
ifName OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
$
Is there any other purpose of MIB files in SNMP management stations?
regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to your list
'documentation' -- i.e., when I want to better understand what a variable
and its values mean, I read the relevant section in the MIB files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables which
the
SNMP agent supports, typically chunked into discrete MIBs (e.g. IF-MIB,
CISCO-STACK-MIB, LLDP-MIB ...)
[The fact that the "sum of all the MIBs" supported by an agent comprise
its
"MIB" bothers me ... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management station
which
permit the station's SNMP libraries to perform the two functions you
describe below. From an operational perspective, useful only to humans,
for
providing translation services between numbers and
more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management stations as
otherwise SNMP queries based on object names would not work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
sysUpTimeInstance 2>/dev/null $ snmpget -M /dir/that/does/not/exist -On
-v
2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense of
returned values. For example here I don't have Cisco MIBs installed and
it
is difficult to understand what "33939721.372808280" or
"68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.33939721.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and I can
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 | head
-3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management stations?
thanks,
Martin
------------------------------------------------------------------------------
Don't Limit Your Business. Reach for the Cloud.
GigeNET's Cloud Solutions provide you with the tools and support that you
need to offload your IT needs and focus on growing your business.
Configured For All Businesses. Start Your Cloud Today.
https://www.gigenetcloud.com/
_______________________________________________
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Robson, Alan

2015-07-08 15:26:01 UTC

Permalink

They can help associate notifications that indicate alarm conditions with notifications that indicate that the same alarm has cleared.

In the normal run of events, the MIB text file is the only way one would learn what notifications are supported without reading the source code since walking the agent won't reveal them.

Alan

-----Original Message-----
From: Martin T [mailto:***@gmail.com]
Sent: Wednesday, July 08, 2015 6:53 AM
To: ***@alleninstitute.org
Cc: net-snmp-***@lists.sourceforge.net
Subject: Re: purpose of MIB files in SNMP management stations

One additional purpose, which falls more or less under documentation, is that MIB files give a fairly good overview what exactly a SNMP agent on a device supports. On the other hand, this could be observed with snmpwalking the device?

regards,
Martin

Post by Martin T
Stuart,
yes, MIB files are a great way to look up for additional information
$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/* ifName
OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
$
Is there any other purpose of MIB files in SNMP management stations?
regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to your
list 'documentation' -- i.e., when I want to better understand what a
variable and its values mean, I read the relevant section in the MIB files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables
which the SNMP agent supports, typically chunked into discrete MIBs
(e.g. IF-MIB, CISCO-STACK-MIB, LLDP-MIB ...) [The fact that the "sum
of all the MIBs" supported by an agent comprise its "MIB" bothers me
... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management station
which permit the station's SNMP libraries to perform the two
functions you describe below. From an operational perspective,
useful only to humans, for providing translation services between
numbers and more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management
stations as otherwise SNMP queries based on object names would not
work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
sysUpTimeInstance 2>/dev/null $ snmpget -M /dir/that/does/not/exist
-On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense of
returned values. For example here I don't have Cisco MIBs installed
and it is difficult to understand what "33939721.372808280" or
"68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.33939721
.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115
.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115
.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and I
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 |
head
-3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry
.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry
.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry
.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management stations?
thanks,
Martin
---------------------------------------------------------------------
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Martin T

2015-07-08 15:43:02 UTC

Permalink

Alan,

thanks for reply! Do you mean a situation where under normal
conditions(i.e. there is no alarm) the SNMP object is not present, but
it will appear once the alarm is active and disappears once the alarm
disappears?

Martin

Post by Robson, Alan
They can help associate notifications that indicate alarm conditions with
notifications that indicate that the same alarm has cleared.
In the normal run of events, the MIB text file is the only way one would
learn what notifications are supported without reading the source code since
walking the agent won't reveal them.
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 6:53 AM
Subject: Re: purpose of MIB files in SNMP management stations
One additional purpose, which falls more or less under documentation, is
that MIB files give a fairly good overview what exactly a SNMP agent on a
device supports. On the other hand, this could be observed with snmpwalking
the device?
regards,
Martin

Post by Martin T
Stuart,
yes, MIB files are a great way to look up for additional information
$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/* ifName
OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
$
Is there any other purpose of MIB files in SNMP management stations?
regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to your
list 'documentation' -- i.e., when I want to better understand what a
variable and its values mean, I read the relevant section in the MIB
files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables
which the SNMP agent supports, typically chunked into discrete MIBs
(e.g. IF-MIB, CISCO-STACK-MIB, LLDP-MIB ...) [The fact that the "sum
of all the MIBs" supported by an agent comprise its "MIB" bothers me
... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management station
which permit the station's SNMP libraries to perform the two
functions you describe below. From an operational perspective,
useful only to humans, for providing translation services between
numbers and more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management
stations as otherwise SNMP queries based on object names would not
work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
sysUpTimeInstance 2>/dev/null $ snmpget -M /dir/that/does/not/exist
-On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense of
returned values. For example here I don't have Cisco MIBs installed
and it is difficult to understand what "33939721.372808280" or
"68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.33939721
.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115
.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.68690115
.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and I
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 |
head
-3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry
.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry
.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry
.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management
stations?
thanks,
Martin
---------------------------------------------------------------------
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Robson, Alan

2015-07-08 16:04:10 UTC

Permalink

Consider this part of the IF-MIB...

linkDown NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkDown trap signifies that the SNMP entity, acting in
an agent role, has detected that the ifOperStatus object for
one of its communication links is about to enter the down
state from some other state (but not from the notPresent
state). This other state is indicated by the included value
of ifOperStatus."
::= { snmpTraps 3 }

linkUp NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkUp trap signifies that the SNMP entity, acting in an
agent role, has detected that the ifOperStatus object for
one of its communication links left the down state and
transitioned into some other state (but not into the
notPresent state). This other state is indicated by the
included value of ifOperStatus."
::= { snmpTraps 4 }

These are messages that may be sent by the device when an interface goes down or come up. They occur spontaneously in reaction to network events they are not something that can be collected from the SNMP agent using SNMPGET or SNMPWALK etc. Using some imagination, the linkup should be considered to be a resolution to a linkDown event though that is not clearly expressed in the text above and is certainly nowhere to be found in the SNMP packet if you were to capture it and pull it apart with wireshark or tcpdump.

Cheers

Alan

-----Original Message-----
From: Martin T [mailto:***@gmail.com]
Sent: Wednesday, July 08, 2015 8:43 AM
To: Robson, Alan
Cc: ***@alleninstitute.org; net-snmp-***@lists.sourceforge.net
Subject: Re: purpose of MIB files in SNMP management stations

Alan,

thanks for reply! Do you mean a situation where under normal conditions(i.e. there is no alarm) the SNMP object is not present, but it will appear once the alarm is active and disappears once the alarm disappears?

Martin

Post by Robson, Alan
They can help associate notifications that indicate alarm conditions
with notifications that indicate that the same alarm has cleared.
In the normal run of events, the MIB text file is the only way one
would learn what notifications are supported without reading the
source code since walking the agent won't reveal them.
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 6:53 AM
Subject: Re: purpose of MIB files in SNMP management stations
One additional purpose, which falls more or less under documentation,
is that MIB files give a fairly good overview what exactly a SNMP
agent on a device supports. On the other hand, this could be observed
with snmpwalking the device?
regards,
Martin

Post by Martin T
Stuart,
yes, MIB files are a great way to look up for additional information
$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/* ifName
OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
$
Is there any other purpose of MIB files in SNMP management stations?
regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to your
list 'documentation' -- i.e., when I want to better understand what
a variable and its values mean, I read the relevant section in the
MIB files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables
which the SNMP agent supports, typically chunked into discrete MIBs
(e.g. IF-MIB, CISCO-STACK-MIB, LLDP-MIB ...) [The fact that the "sum
of all the MIBs" supported by an agent comprise its "MIB" bothers me
... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management
station which permit the station's SNMP libraries to perform the two
functions you describe below. From an operational perspective,
useful only to humans, for providing translation services between
numbers and more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management
stations as otherwise SNMP queries based on object names would not
work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
sysUpTimeInstance 2>/dev/null $ snmpget -M /dir/that/does/not/exist
-On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense
of returned values. For example here I don't have Cisco MIBs
installed and it is difficult to understand what
"33939721.372808280" or "68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.3393972
1
.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.6869011
5
.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.6869011
5
.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 |
head
-3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntr
y
.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntr
y
.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntr
y
.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management
stations?
thanks,
Martin
--------------------------------------------------------------------
-
--------- Don't Limit Your Business. Reach for the Cloud.
GigeNET's Cloud Solutions provide you with the tools and support
that you need to offload your IT needs and focus on growing your business.
Configured For All Businesses. Start Your Cloud Today.
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.gigenetclou
d
.com_&d=AwICAg&c=jcv3orpCsv7C4ly8-ubDob57ycZ4jvhoYZNDBA06fPk&r=xN9An
M
DZvO_QvUZQZcoply6WFqSJuNcpv-dDu2fA4Ac&m=qkZkC5naV7pjeqaVw1JU0UToEFi8
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bDob57ycZ4jvhoYZNDBA06fPk&r=xN9AnMDZvO_QvUZQZcoply6WFqSJuNcpv-dDu2fA
4
Ac&m=qkZkC5naV7pjeqaVw1JU0UToEFi82ekN7AB-CL_aaVM&s=id8ClahC5rXRyjwj_
t
mqFEmHr5FFmNXoBMHE-wlFDSs&e=

----------------------------------------------------------------------
-------- Don't Limit Your Business. Reach for the Cloud.
GigeNET's Cloud Solutions provide you with the tools and support that
you need to offload your IT needs and focus on growing your business.
Configured For All Businesses. Start Your Cloud Today.
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.gigenetcloud.
com_&d=AwICAg&c=jcv3orpCsv7C4ly8-ubDob57ycZ4jvhoYZNDBA06fPk&r=xN9AnMDZ
vO_QvUZQZcoply6WFqSJuNcpv-dDu2fA4Ac&m=qkZkC5naV7pjeqaVw1JU0UToEFi82ekN
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ob57ycZ4jvhoYZNDBA06fPk&r=xN9AnMDZvO_QvUZQZcoply6WFqSJuNcpv-dDu2fA4Ac&
m=qkZkC5naV7pjeqaVw1JU0UToEFi82ekN7AB-CL_aaVM&s=id8ClahC5rXRyjwj_tmqFE
mHr5FFmNXoBMHE-wlFDSs&e=

Martin T

2015-07-09 08:59:33 UTC

Permalink

Alan,

so in a nutshell, MIB files are the only place to search for SNMP
traps supported by SNMP agent?

thanks,
Martin

Post by Robson, Alan
Consider this part of the IF-MIB...
linkDown NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkDown trap signifies that the SNMP entity, acting in
an agent role, has detected that the ifOperStatus object for
one of its communication links is about to enter the down
state from some other state (but not from the notPresent
state). This other state is indicated by the included value
of ifOperStatus."
::= { snmpTraps 3 }
linkUp NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkUp trap signifies that the SNMP entity, acting in an
agent role, has detected that the ifOperStatus object for
one of its communication links left the down state and
transitioned into some other state (but not into the
notPresent state). This other state is indicated by the
included value of ifOperStatus."
::= { snmpTraps 4 }
These are messages that may be sent by the device when an interface goes
down or come up. They occur spontaneously in reaction to network events they
are not something that can be collected from the SNMP agent using SNMPGET or
SNMPWALK etc. Using some imagination, the linkup should be considered to be
a resolution to a linkDown event though that is not clearly expressed in the
text above and is certainly nowhere to be found in the SNMP packet if you
were to capture it and pull it apart with wireshark or tcpdump.
Cheers
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 8:43 AM
To: Robson, Alan
Subject: Re: purpose of MIB files in SNMP management stations
Alan,
thanks for reply! Do you mean a situation where under normal conditions(i.e.
there is no alarm) the SNMP object is not present, but it will appear once
the alarm is active and disappears once the alarm disappears?
Martin

Post by Robson, Alan
They can help associate notifications that indicate alarm conditions
with notifications that indicate that the same alarm has cleared.
In the normal run of events, the MIB text file is the only way one
would learn what notifications are supported without reading the
source code since walking the agent won't reveal them.
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 6:53 AM
Subject: Re: purpose of MIB files in SNMP management stations
One additional purpose, which falls more or less under documentation,
is that MIB files give a fairly good overview what exactly a SNMP
agent on a device supports. On the other hand, this could be observed
with snmpwalking the device?
regards,
Martin

Post by Martin T
Stuart,
yes, MIB files are a great way to look up for additional information
$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/* ifName
OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
$
Is there any other purpose of MIB files in SNMP management stations?
regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to your
list 'documentation' -- i.e., when I want to better understand what
a variable and its values mean, I read the relevant section in the
MIB files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables
which the SNMP agent supports, typically chunked into discrete MIBs
(e.g. IF-MIB, CISCO-STACK-MIB, LLDP-MIB ...) [The fact that the "sum
of all the MIBs" supported by an agent comprise its "MIB" bothers me
... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management
station which permit the station's SNMP libraries to perform the two
functions you describe below. From an operational perspective,
useful only to humans, for providing translation services between
numbers and more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management
stations as otherwise SNMP queries based on object names would not
work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
sysUpTimeInstance 2>/dev/null $ snmpget -M /dir/that/does/not/exist
-On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense
of returned values. For example here I don't have Cisco MIBs
installed and it is difficult to understand what
"33939721.372808280" or "68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.3393972
1
.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.6869011
5
.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.6869011
5
.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 |
head
-3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntr
y
.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntr
y
.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntr
y
.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management
stations?
thanks,
Martin
--------------------------------------------------------------------
-
--------- Don't Limit Your Business. Reach for the Cloud.
GigeNET's Cloud Solutions provide you with the tools and support
that you need to offload your IT needs and focus on growing your
business.
Configured For All Businesses. Start Your Cloud Today.
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.gigenetclou
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.com_&d=AwICAg&c=jcv3orpCsv7C4ly8-ubDob57ycZ4jvhoYZNDBA06fPk&r=xN9An
M
DZvO_QvUZQZcoply6WFqSJuNcpv-dDu2fA4Ac&m=qkZkC5naV7pjeqaVw1JU0UToEFi8
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t
mqFEmHr5FFmNXoBMHE-wlFDSs&e=

----------------------------------------------------------------------
-------- Don't Limit Your Business. Reach for the Cloud.
GigeNET's Cloud Solutions provide you with the tools and support that
you need to offload your IT needs and focus on growing your business.
Configured For All Businesses. Start Your Cloud Today.
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.gigenetcloud.
com_&d=AwICAg&c=jcv3orpCsv7C4ly8-ubDob57ycZ4jvhoYZNDBA06fPk&r=xN9AnMDZ
vO_QvUZQZcoply6WFqSJuNcpv-dDu2fA4Ac&m=qkZkC5naV7pjeqaVw1JU0UToEFi82ekN
7AB-CL_aaVM&s=eM5wtQ2xc9HKxHsZOkGNzbMlSqkuk454q2bh36t1usg&e=
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ob57ycZ4jvhoYZNDBA06fPk&r=xN9AnMDZvO_QvUZQZcoply6WFqSJuNcpv-dDu2fA4Ac&
m=qkZkC5naV7pjeqaVw1JU0UToEFi82ekN7AB-CL_aaVM&s=id8ClahC5rXRyjwj_tmqFE
mHr5FFmNXoBMHE-wlFDSs&e=

Robson, Alan

2015-07-09 15:47:51 UTC

Permalink

The vendor sometimes provides information too, aside from the MIB files.

Also, I have to say that the device does not need to be listening for requests on port UDP:161 (the traditional role of an agent) in order to send traps. That is, it can send traps without having an SNMP agent running in the traditional sense. For example, you can send a trap from the commandline of a machine that is not running snmpd.

Alan

-----Original Message-----
From: Martin T [mailto:***@gmail.com]
Sent: Thursday, July 09, 2015 2:00 AM
To: Robson, Alan
Cc: ***@alleninstitute.org; net-snmp-***@lists.sourceforge.net
Subject: Re: purpose of MIB files in SNMP management stations

Alan,

so in a nutshell, MIB files are the only place to search for SNMP traps supported by SNMP agent?

thanks,
Martin

Post by Robson, Alan
Consider this part of the IF-MIB...
linkDown NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkDown trap signifies that the SNMP entity, acting in
an agent role, has detected that the ifOperStatus object for
one of its communication links is about to enter the down
state from some other state (but not from the notPresent
state). This other state is indicated by the included value
of ifOperStatus."
::= { snmpTraps 3 }
linkUp NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkUp trap signifies that the SNMP entity, acting in an
agent role, has detected that the ifOperStatus object for
one of its communication links left the down state and
transitioned into some other state (but not into the
notPresent state). This other state is indicated by the
included value of ifOperStatus."
::= { snmpTraps 4 }
These are messages that may be sent by the device when an interface
goes down or come up. They occur spontaneously in reaction to network
events they are not something that can be collected from the SNMP
agent using SNMPGET or SNMPWALK etc. Using some imagination, the
linkup should be considered to be a resolution to a linkDown event
though that is not clearly expressed in the text above and is
certainly nowhere to be found in the SNMP packet if you were to capture it and pull it apart with wireshark or tcpdump.
Cheers
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 8:43 AM
To: Robson, Alan
Subject: Re: purpose of MIB files in SNMP management stations
Alan,
thanks for reply! Do you mean a situation where under normal conditions(i.e.
there is no alarm) the SNMP object is not present, but it will appear
once the alarm is active and disappears once the alarm disappears?
Martin

Post by Robson, Alan
They can help associate notifications that indicate alarm conditions
with notifications that indicate that the same alarm has cleared.
In the normal run of events, the MIB text file is the only way one
would learn what notifications are supported without reading the
source code since walking the agent won't reveal them.
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 6:53 AM
Subject: Re: purpose of MIB files in SNMP management stations
One additional purpose, which falls more or less under documentation,
is that MIB files give a fairly good overview what exactly a SNMP
agent on a device supports. On the other hand, this could be observed
with snmpwalking the device?
regards,
Martin

Post by Martin T
Stuart,
yes, MIB files are a great way to look up for additional information
$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/* ifName
OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
$
Is there any other purpose of MIB files in SNMP management stations?
regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to
your list 'documentation' -- i.e., when I want to better understand
what a variable and its values mean, I read the relevant section in
the MIB files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables
which the SNMP agent supports, typically chunked into discrete MIBs
(e.g. IF-MIB, CISCO-STACK-MIB, LLDP-MIB ...) [The fact that the
"sum of all the MIBs" supported by an agent comprise its "MIB"
bothers me ... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management
station which permit the station's SNMP libraries to perform the
two functions you describe below. From an operational perspective,
useful only to humans, for providing translation services between
numbers and more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management
stations as otherwise SNMP queries based on object names would not
work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public
10.10.10.1 sysUpTimeInstance 2>/dev/null $ snmpget -M
/dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense
of returned values. For example here I don't have Cisco MIBs
installed and it is difficult to understand what
"33939721.372808280" or "68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.339397
2
1
.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.686901
1
5
.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.686901
1
5
.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 |
head
-3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEnt
r
y
.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEnt
r
y
.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEnt
r
y
.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management
stations?
thanks,
Martin
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ob57ycZ4jvhoYZNDBA06fPk&r=xN9AnMDZvO_QvUZQZcoply6WFqSJuNcpv-dDu2fA4Ac
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Martin T

2015-07-10 08:57:17 UTC

Permalink

Alan,

thanks!

Martin

Post by Robson, Alan
The vendor sometimes provides information too, aside from the MIB files.
Also, I have to say that the device does not need to be listening for
requests on port UDP:161 (the traditional role of an agent) in order to send
traps. That is, it can send traps without having an SNMP agent running in
the traditional sense. For example, you can send a trap from the commandline
of a machine that is not running snmpd.
Alan
-----Original Message-----
Sent: Thursday, July 09, 2015 2:00 AM
To: Robson, Alan
Subject: Re: purpose of MIB files in SNMP management stations
Alan,
so in a nutshell, MIB files are the only place to search for SNMP traps
supported by SNMP agent?
thanks,
Martin

Post by Robson, Alan
Consider this part of the IF-MIB...
linkDown NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkDown trap signifies that the SNMP entity, acting in
an agent role, has detected that the ifOperStatus object for
one of its communication links is about to enter the down
state from some other state (but not from the notPresent
state). This other state is indicated by the included value
of ifOperStatus."
::= { snmpTraps 3 }
linkUp NOTIFICATION-TYPE
OBJECTS { ifIndex, ifAdminStatus, ifOperStatus }
STATUS current
DESCRIPTION
"A linkUp trap signifies that the SNMP entity, acting in an
agent role, has detected that the ifOperStatus object for
one of its communication links left the down state and
transitioned into some other state (but not into the
notPresent state). This other state is indicated by the
included value of ifOperStatus."
::= { snmpTraps 4 }
These are messages that may be sent by the device when an interface
goes down or come up. They occur spontaneously in reaction to network
events they are not something that can be collected from the SNMP
agent using SNMPGET or SNMPWALK etc. Using some imagination, the
linkup should be considered to be a resolution to a linkDown event
though that is not clearly expressed in the text above and is
certainly nowhere to be found in the SNMP packet if you were to capture it
and pull it apart with wireshark or tcpdump.
Cheers
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 8:43 AM
To: Robson, Alan
Subject: Re: purpose of MIB files in SNMP management stations
Alan,
thanks for reply! Do you mean a situation where under normal
conditions(i.e.
there is no alarm) the SNMP object is not present, but it will appear
once the alarm is active and disappears once the alarm disappears?
Martin

Post by Robson, Alan
They can help associate notifications that indicate alarm conditions
with notifications that indicate that the same alarm has cleared.
In the normal run of events, the MIB text file is the only way one
would learn what notifications are supported without reading the
source code since walking the agent won't reveal them.
Alan
-----Original Message-----
Sent: Wednesday, July 08, 2015 6:53 AM
Subject: Re: purpose of MIB files in SNMP management stations
One additional purpose, which falls more or less under documentation,
is that MIB files give a fairly good overview what exactly a SNMP
agent on a device supports. On the other hand, this could be observed
with snmpwalking the device?
regards,
Martin

Post by Martin T
Stuart,
yes, MIB files are a great way to look up for additional information
$ gsed -n '/^ifName/,/^$/p' /usr/local/share/snmp/mibs/* ifName
OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The textual name of the interface. The value of this
object should be the name of the interface as assigned by
the local device and should be suitable for use in commands
entered at the device's `console'. This might be a text
name, such as `le0' or a simple port number, such as `1',
depending on the interface naming syntax of the device. If
several entries in the ifTable together represent a single
interface as named by the device, then each will have the
same value of ifName. Note that for an agent which
responds
to SNMP queries concerning an interface on some other
(proxied) device, then the value of ifName for such an
interface is the proxied device's local name for it.
$
Is there any other purpose of MIB files in SNMP management stations?
regards,
Martin

Post by Stuart Kendrick
Speaking from an operational perspective, I myself would add to
your list 'documentation' -- i.e., when I want to better understand
what a variable and its values mean, I read the relevant section in
the MIB files.
If they serve any other purpose, I would like to hear about it.
- Management Information Base (MIB): the collection of variables
which the SNMP agent supports, typically chunked into discrete MIBs
(e.g. IF-MIB, CISCO-STACK-MIB, LLDP-MIB ...) [The fact that the
"sum of all the MIBs" supported by an agent comprise its "MIB"
bothers me ... not my idea of clear terminology.]
- MIB Files: the text files stored on the network management
station which permit the station's SNMP libraries to perform the
two functions you describe below. From an operational perspective,
useful only to humans, for providing translation services between
numbers and more-human-comprehensible-strings.
hth,
--sk
-----Original Message-----
Sent: Wednesday, July 08, 2015 4:03 AM
Subject: purpose of MIB files in SNMP management stations
Hi,
it is obvious that MIB's are important for network management
stations as otherwise SNMP queries based on object names would not
work. For
$ snmpget -M /dir/that/does/not/exist -On -v 2c -c public
10.10.10.1 sysUpTimeInstance 2>/dev/null $ snmpget -M
/dir/that/does/not/exist -On -v 2c -c public 10.10.10.1
.1.3.6.1.2.1.1.3.0 2>/dev/null
.1.3.6.1.2.1.1.3.0 = Timeticks: (69843635) 8 days, 2:00:36.35 $
Another purpose of MIB's I can see is that they help to make sense
of returned values. For example here I don't have Cisco MIBs
installed and it is difficult to understand what
"33939721.372808280" or "68690115.642234535"
$ snmpwalk -Of -v 2c -c public 10.10.10.1
.1.3.6.1.4.1.9.9.166.1.17.1.1.9 | head -3
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.339397
2
1
.372808280
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.686901
1
5
.642234535
= Counter32: 0
.iso.org.dod.internet.private.enterprises.9.9.166.1.17.1.1.9.686901
1
5
.724494656
= Counter32: 0
$
On the other hand, here I have required MIB databases installed and
$ snmpwalk -Of -v 2c -c public 10.10.10.1 .1.3.6.1.2.1.31.1.1.1.1 |
head
-3
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEnt
r
y
.ifName.2
= STRING: Null0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEnt
r
y
.ifName.3
= STRING: MgmtEth0/RSP0/CPU0/0
.iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEnt
r
y
.ifName.4
= STRING: MgmtEth0/RSP0/CPU0/1
$
Is there any additional purpose of MIB files in SNMP management
stations?
thanks,
Martin
-------------------------------------------------------------------
-
-
--------- Don't Limit Your Business. Reach for the Cloud.
GigeNET's Cloud Solutions provide you with the tools and support
that you need to offload your IT needs and focus on growing your
business.
Configured For All Businesses. Start Your Cloud Today.
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.gigenetclo
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you need to offload your IT needs and focus on growing your business.
Configured For All Businesses. Start Your Cloud Today.
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