snmpbulkget ?

[czezz]

Hello,
I need an advice about that short SNMP "tcpdump" that I attach below.
That dump presents series of SNMPBULKGET queries.

However what I can see is: 2 SNMP BULK GET and rest seems to be a standard SNMP GET.
Can anyone verify this for me, please ?

---BEGIN---
# tcpdump -i eth0 dst host 192.168.10.146
10:33:06.028987 IP monitor01.a254.mgmt.net.59292 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(28) system.sysName.0
10:33:06.031908 IP monitor01.a254.mgmt.net.56225 > node-0.freestation.net.snmp: C=s1gcUst0 GetBulk(29) N=0 M=20 interfaces.ifTable.ifEntry.ifDescr
10:33:06.036959 IP monitor01.a254.mgmt.net.56225 > node-0.freestation.net.snmp: C=s1gcUst0 GetBulk(30) N=0 M=20 interfaces.ifTable.ifEntry.ifDescr.4
10:33:06.042092 IP monitor01.a254.mgmt.net.51576 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.6.1
10:33:06.044737 IP monitor01.a254.mgmt.net.35801 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.10.1
10:33:06.047311 IP monitor01.a254.mgmt.net.47288 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(30) interfaces.ifTable.ifEntry.ifInErrors.1
10:33:06.049885 IP monitor01.a254.mgmt.net.35038 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(30) interfaces.ifTable.ifEntry.ifOutErrors.1
10:33:06.052422 IP monitor01.a254.mgmt.net.53358 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.7.1
10:33:06.055020 IP monitor01.a254.mgmt.net.51026 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.11.1
10:33:06.057600 IP monitor01.a254.mgmt.net.53960 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.8.1
10:33:06.060127 IP monitor01.a254.mgmt.net.41782 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.12.1
10:33:06.062724 IP monitor01.a254.mgmt.net.43091 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.9.1
10:33:06.065330 IP monitor01.a254.mgmt.net.39926 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.13.1
10:33:06.067881 IP monitor01.a254.mgmt.net.47567 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.6.2
10:33:06.070495 IP monitor01.a254.mgmt.net.48867 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.10.2
10:33:06.073115 IP monitor01.a254.mgmt.net.44131 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(30) interfaces.ifTable.ifEntry.ifInErrors.2
10:33:06.076617 IP monitor01.a254.mgmt.net.55235 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(30) interfaces.ifTable.ifEntry.ifOutErrors.2
10:33:06.079176 IP monitor01.a254.mgmt.net.59712 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.7.2
10:33:06.081785 IP monitor01.a254.mgmt.net.41576 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.11.2
10:33:06.084368 IP monitor01.a254.mgmt.net.38409 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.8.2
10:33:06.086982 IP monitor01.a254.mgmt.net.35333 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.12.2
10:33:06.089782 IP monitor01.a254.mgmt.net.43765 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.9.2
10:33:06.092333 IP monitor01.a254.mgmt.net.40070 > node-0.freestation.net.snmp: C=s1gcUst0 GetRequest(31) 31.1.1.1.13.2
---END---

Best Regards,
czezz

[Joel Hansell]

Hi czezz,

I can see what you see ... tcpdump is claiming to receive 2 GetBulk
requests, and a whole bunch of GetRequests.
I'm not sure what kind of answer you expect ... Is this not the output
you expected from tcpdump? In that case, perhaps you could describe in
more detail what was happening, and why you should not see this
particular output?

BR,
Joel Hansell

On Wed, May 23, 2012 at 4:13 PM, czezz <***@o2.pl> wrote:
> Hello,
> I need an advice about that short SNMP "tcpdump" that I attach below.
> That dump presents series of SNMPBULKGET queries.
>
> However what I can see is: 2 SNMP BULK GET and rest seems to be a standard SNMP GET.
> Can anyone verify this for me, please ?
>
> ---BEGIN---
> # tcpdump -i eth0 dst host 192.168.10.146
> 10:33:06.028987 IP monitor01.a254.mgmt.net.59292 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(28)  system.sysName.0
> 10:33:06.031908 IP monitor01.a254.mgmt.net.56225 > node-0.freestation.net.snmp:  C=s1gcUst0 GetBulk(29)  N=0 M=20 interfaces.ifTable.ifEntry.ifDescr
> 10:33:06.036959 IP monitor01.a254.mgmt.net.56225 > node-0.freestation.net.snmp:  C=s1gcUst0 GetBulk(30)  N=0 M=20 interfaces.ifTable.ifEntry.ifDescr.4
> 10:33:06.042092 IP monitor01.a254.mgmt.net.51576 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.6.1
> 10:33:06.044737 IP monitor01.a254.mgmt.net.35801 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.10.1
> 10:33:06.047311 IP monitor01.a254.mgmt.net.47288 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifInErrors.1
> 10:33:06.049885 IP monitor01.a254.mgmt.net.35038 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifOutErrors.1
> 10:33:06.052422 IP monitor01.a254.mgmt.net.53358 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.7.1
> 10:33:06.055020 IP monitor01.a254.mgmt.net.51026 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.11.1
> 10:33:06.057600 IP monitor01.a254.mgmt.net.53960 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.8.1
> 10:33:06.060127 IP monitor01.a254.mgmt.net.41782 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.12.1
> 10:33:06.062724 IP monitor01.a254.mgmt.net.43091 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.9.1
> 10:33:06.065330 IP monitor01.a254.mgmt.net.39926 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.13.1
> 10:33:06.067881 IP monitor01.a254.mgmt.net.47567 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.6.2
> 10:33:06.070495 IP monitor01.a254.mgmt.net.48867 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.10.2
> 10:33:06.073115 IP monitor01.a254.mgmt.net.44131 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifInErrors.2
> 10:33:06.076617 IP monitor01.a254.mgmt.net.55235 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifOutErrors.2
> 10:33:06.079176 IP monitor01.a254.mgmt.net.59712 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.7.2
> 10:33:06.081785 IP monitor01.a254.mgmt.net.41576 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.11.2
> 10:33:06.084368 IP monitor01.a254.mgmt.net.38409 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.8.2
> 10:33:06.086982 IP monitor01.a254.mgmt.net.35333 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.12.2
> 10:33:06.089782 IP monitor01.a254.mgmt.net.43765 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.9.2
> 10:33:06.092333 IP monitor01.a254.mgmt.net.40070 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.13.2
> ---END---
>
> Best Regards,
> czezz
>
> ------------------------------------------------------------------------------
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> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
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>

[czezz]

Hi Joel,
thanks for your reply.
The output I have presented previously was done by PHP script and now it makes more and more senese for me.

One more thing I would like to understand about SNMP BULK.
I was told that BULK makes less network traffic. And yes - I can see that when I execute snmpbulkWALK.
However what is the point of using snmpBULKGET instead of regular snmpGET ?
It seems to make exactly this same volume of traffic.
Here is a simple example just for one query:

snmpbulkget:
15:57:26.543961 IP monitor01.a254.mgmt.net.41561 > node-0.freestation.net.snmp: C=public GetBulk(30) N=0 M=10 interfaces.ifTable.ifEntry.ifAdminStatus.1
^C
1 packets captured
1 packets received by filter
0 packets dropped by kernel

snmpget:
15:57:14.983627 IP monitor01.a254.mgmt.net.54509 > node-0.freestation.net.snmp: C=public GetRequest(30) interfaces.ifTable.ifEntry.ifAdminStatus.1
^C
1 packets captured
1 packets received by filter
0 packets dropped by kernel

Means: volume of 100 snmpget queries is equal 100 of snmpbulkget queries. Is that correct ?

Thanks,
czezz


Dnia 23 maja 2012 17:18 Joel Hansell <***@gmail.com> napisał(a):

> Hi czezz,
>
> I can see what you see ... tcpdump is claiming to receive 2 GetBulk
> requests, and a whole bunch of GetRequests.
> I'm not sure what kind of answer you expect ... Is this not the output
> you expected from tcpdump? In that case, perhaps you could describe in
> more detail what was happening, and why you should not see this
> particular output?
>
> BR,
> Joel Hansell
>
> On Wed, May 23, 2012 at 4:13 PM, czezz <***@o2.pl> wrote:
> > Hello,
> > I need an advice about that short SNMP "tcpdump" that I attach below.
> > That dump presents series of SNMPBULKGET queries.
> >
> > However what I can see is: 2 SNMP BULK GET and rest seems to be a standard SNMP GET.
> > Can anyone verify this for me, please ?
> >
> > ---BEGIN---
> > # tcpdump -i eth0 dst host 192.168.10.146
> > 10:33:06.028987 IP monitor01.a254.mgmt.net.59292 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(28)  system.sysName.0
> > 10:33:06.031908 IP monitor01.a254.mgmt.net.56225 > node-0.freestation.net.snmp:  C=s1gcUst0 GetBulk(29)  N=0 M=20 interfaces.ifTable.ifEntry.ifDescr
> > 10:33:06.036959 IP monitor01.a254.mgmt.net.56225 > node-0.freestation.net.snmp:  C=s1gcUst0 GetBulk(30)  N=0 M=20 interfaces.ifTable.ifEntry.ifDescr.4
> > 10:33:06.042092 IP monitor01.a254.mgmt.net.51576 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.6.1
> > 10:33:06.044737 IP monitor01.a254.mgmt.net.35801 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.10.1
> > 10:33:06.047311 IP monitor01.a254.mgmt.net.47288 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifInErrors.1
> > 10:33:06.049885 IP monitor01.a254.mgmt.net.35038 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifOutErrors.1
> > 10:33:06.052422 IP monitor01.a254.mgmt.net.53358 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.7.1
> > 10:33:06.055020 IP monitor01.a254.mgmt.net.51026 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.11.1
> > 10:33:06.057600 IP monitor01.a254.mgmt.net.53960 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.8.1
> > 10:33:06.060127 IP monitor01.a254.mgmt.net.41782 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.12.1
> > 10:33:06.062724 IP monitor01.a254.mgmt.net.43091 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.9.1
> > 10:33:06.065330 IP monitor01.a254.mgmt.net.39926 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.13.1
> > 10:33:06.067881 IP monitor01.a254.mgmt.net.47567 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.6.2
> > 10:33:06.070495 IP monitor01.a254.mgmt.net.48867 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.10.2
> > 10:33:06.073115 IP monitor01.a254.mgmt.net.44131 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifInErrors.2
> > 10:33:06.076617 IP monitor01.a254.mgmt.net.55235 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(30)  interfaces.ifTable.ifEntry.ifOutErrors.2
> > 10:33:06.079176 IP monitor01.a254.mgmt.net.59712 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.7.2
> > 10:33:06.081785 IP monitor01.a254.mgmt.net.41576 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.11.2
> > 10:33:06.084368 IP monitor01.a254.mgmt.net.38409 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.8.2
> > 10:33:06.086982 IP monitor01.a254.mgmt.net.35333 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.12.2
> > 10:33:06.089782 IP monitor01.a254.mgmt.net.43765 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.9.2
> > 10:33:06.092333 IP monitor01.a254.mgmt.net.40070 > node-0.freestation.net.snmp:  C=s1gcUst0 GetRequest(31)  31.1.1.1.13.2
> > ---END---
> >
> > Best Regards,
> > czezz
> >
> > ------------------------------------------------------------------------------
> > Live Security Virtual Conference
> > Exclusive live event will cover all the ways today's security and
> > threat landscape has changed and how IT managers can respond. Discussions
> > will include endpoint security, mobile security and the latest in malware
> > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> > _______________________________________________
> > Net-snmp-users mailing list
> > Net-snmp-***@lists.sourceforge.net
> > Please see the following page to unsubscribe or change other options:
> > https://lists.sourceforge.net/lists/listinfo/net-snmp-users
> >
>

[Dave Shield]

On 23 May 2012 17:18, czezz <***@o2.pl> wrote:
> However what is the point of using snmpBULKGET instead of regular snmpGET ?

If you are requesting a single value, then there is no benefit.
The advantage of GetBulk (compared to simple GetNext) comes when you
are retrieving a sequence of values - for example, when walking a table.


Try comparing

snmpbulkget .... ifAdminStatus
vs
snmpwalk .... ifAdminStatus

If there are eight or nine rows in the table, then "snmpbulkget" will issue
a single GetBulk request, and receive a single response containing
all the relevant values.
In contrast, "snmpwalk" would need to send nine or ten GetNext
requests (with the same number of Response packets) to retrieve
the same information.

Dave

[czezz]

Hello Dave,
I am going to use SNMPBULKGET only.
So, just to have a good understanding - in this case I will get no benefits comparing to regular SNMPGET, is this correct ?

With SNMPGET or SNMPBULKGET I request for specific OID and in my understanding I will always get singe value (eg. ifAdminStatus.1).
I wont use SNMPWALK and SNMPGULKWALK.

Thanks,
czezz


Dnia 23 maja 2012 20:56 Dave Shield <***@liverpool.ac.uk> napisał(a):

> On 23 May 2012 17:18, czezz <***@o2.pl> wrote:
> > However what is the point of using snmpBULKGET instead of regular snmpGET ?
>
> If you are requesting a single value, then there is no benefit.
> The advantage of GetBulk (compared to simple GetNext) comes when you
> are retrieving a sequence of values - for example, when walking a table.
>
>
> Try comparing
>
> snmpbulkget .... ifAdminStatus
> vs
> snmpwalk .... ifAdminStatus
>
> If there are eight or nine rows in the table, then "snmpbulkget" will issue
> a single GetBulk request, and receive a single response containing
> all the relevant values.
> In contrast, "snmpwalk" would need to send nine or ten GetNext
> requests (with the same number of Response packets) to retrieve
> the same information.
>
> Dave
>

[Dave Shield]

On 24 May 2012 08:20, czezz <***@o2.pl> wrote:
> I am going to use SNMPBULKGET only.
> So, just to have a good understanding - in this case I will get no benefits
> comparing to regular SNMPGET, is this correct ?

It doesn't really make sense to compare Get vs GetBulk.
They are doing two different tasks.
The more sensible comparison is between GetNext and GetBulk.


> With SNMPGET or SNMPBULKGET I request for specific OID
> and in my understanding I will always get singe value (eg. ifAdminStatus.1).

Not quite.

With the SNMP Get request, you ask for a list of (one or more) OIDs,
and receive the corresponding values - the same number as requested OIDs
(and for those precise OIDs). If you ask for one OID, you'll get one answer.
(And if you ask for the wrong OID, you won't get anything.)

With the SNMP GetNext request, you ask for a list of (one or more) OIDs,
and receive a list of the "next" OID/value pairs. Again, the same number
of values as originally requested OIDs. If you ask for one OID, you'll
still get one answer.
(But you should always get something back, even if you ask for the "wrong" OID).

GetBulk is primarily a supercharged GetNext - you ask for a list of (one or
more) OIDs, and receive a longer list of the N "next" OID/value pairs.
Typically, if you ask for one OID, you might receive ten answers.
(The precise number depends on how you specified the original query)

If you only want a single answer back, then don't use GetBulk.
It doesn't gain you anything, and just puts extra processing load
on the receiving agent.


> I wont use SNMPWALK and SNMPGULKWALK.

Remember there is no such thing as a "Walk" (or "BulkWalk") request
within the SNMP protocol. These are simply client commands that send
a sequence of GetNext (or GetBulk) requests, to retrieve a larger block
of information.

Dave

[czezz]

So, assuming:
- to get single value, the most beneficial is reguler SNMPGET (the lowest data traffic and the lowest proccessing load on agent). Is that right ?

SNMPGET = Get request
SNMPWALK = GetNext
SNMPBULKGET && SANPBULKWALK = GetBulk

Thanks,
czezz


Dnia 24 maja 2012 10:43 Dave Shield <***@liverpool.ac.uk> napisał(a):

> On 24 May 2012 08:20, czezz <***@o2.pl> wrote:
> > I am going to use SNMPBULKGET only.
> > So, just to have a good understanding - in this case I will get no benefits
> > comparing to regular SNMPGET, is this correct ?
>
> It doesn't really make sense to compare Get vs GetBulk.
> They are doing two different tasks.
> The more sensible comparison is between GetNext and GetBulk.
>
>
> > With SNMPGET or SNMPBULKGET I request for specific OID
> > and in my understanding I will always get singe value (eg. ifAdminStatus.1).
>
> Not quite.
>
> With the SNMP Get request, you ask for a list of (one or more) OIDs,
> and receive the corresponding values - the same number as requested OIDs
> (and for those precise OIDs). If you ask for one OID, you'll get one answer.
> (And if you ask for the wrong OID, you won't get anything.)
>
> With the SNMP GetNext request, you ask for a list of (one or more) OIDs,
> and receive a list of the "next" OID/value pairs. Again, the same number
> of values as originally requested OIDs. If you ask for one OID, you'll
> still get one answer.
> (But you should always get something back, even if you ask for the "wrong" OID).
>
> GetBulk is primarily a supercharged GetNext - you ask for a list of (one or
> more) OIDs, and receive a longer list of the N "next" OID/value pairs.
> Typically, if you ask for one OID, you might receive ten answers.
> (The precise number depends on how you specified the original query)
>
> If you only want a single answer back, then don't use GetBulk.
> It doesn't gain you anything, and just puts extra processing load
> on the receiving agent.
>
>
> > I wont use SNMPWALK and SNMPGULKWALK.
>
> Remember there is no such thing as a "Walk" (or "BulkWalk") request
> within the SNMP protocol. These are simply client commands that send
> a sequence of GetNext (or GetBulk) requests, to retrieve a larger block
> of information.
>
> Dave
>

[Dave Shield]

On 24 May 2012 10:20, czezz <***@o2.pl> wrote:
> So, assuming:
> - to get single value, the most beneficial is reguler SNMPGET

Assuming you know the index value of the object you require - yes.
(If not, then use GetNext)


> SNMPGET = Get request
> SNMPGETNEXT & SNMPWALK = GetNext
> SNMPBULKGET & SNMPBULKWALK = GetBulk

Correct.

(Also bear in mind that GetBulk is only available with SNMP v2c & v3.
It can't be used with SNMPv1)

Dave

[Suresh kumar]

[Dave Shield]

On 24 May 2012 18:27, Suresh kumar <***@hotmail.com> wrote:
> what is diffrent between snmpbulkget nad snmpbulkwalk ?.

snmpbulkget sends a single GetBulk request, and repoerts the
results (regardless of what they happen to be). It's a simple
command wrapper round the basic SNMP protocol request.

snmpbulkwalk sends a sequence of GetBulk requests,
designed to display all the information underneath the specified
starting point. If this requires two, three or more GetBulk requests
to retrieve this information, then that's what it will use. Conversely,
if it receives varbinds that fall outside the area of interest, it will
discard them (in contrast to snmpbulkget, which will display
all the varbinds it receives).


Try running

snmpbulkget .... sysUpTime
vs
snmpbulkwalk .... sysUpTime

or
snmpbulkget .... hrSWRunName
vs
snmpbulkwalk .... hrSWRunName

to see the difference.

Dave