SNMPv3: SNMP queries are possible although no view has been configured.

[Johannes_Grimm]

Hello everyone,

when I configure my snmp-server group I need to add a write view to give an external appliance the ability to make write changes via snmp on the switch. This functions also if I have not configured a view. 

For example:

snmp-server group TEST v3 priv write ViewDoesNotExist

Which view will be used if the configured view is not availiable? Is there a default view? 

Many thanks for your help.

Best regards,

Johannes

[Mark Malone]

Hi
Yes a default view v1default

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/configuration/xe-3se/3850/snmp-xe-3se-3850-book/nm-snmp-snmpv3.html

Example:

Device# show snmp group

groupname: V1 security model:v1
readview : v1default writeview: <no writeview specified>
notifyview: <no notifyview specified>
row status: active
groupname: ILMI security model:v1
readview : *ilmi writeview: *ilmi
notifyview: <no notifyview specified>
row status: active
groupname: ILMI security model:v2c
readview : *ilmi writeview: *ilmi
notifyview: <no notifyview specified>
row status: active
groupname: group1 security model:v1
readview : v1default writeview: <no writeview specified>
notifyview: <no notifyview specified>
row status: active

[Johannes_Grimm]

Hi Mark,

thank you for the fast answer

On my equipment (in this case a C3650  with 16.6.5) the view v1default is only configured as read view.

groupname: TEST security model:v3 priv
contextname: <no context specified> storage-type: nonvolatile
readview : v1default writeview: ViewDoesNotExist
notifyview: *tv.FFFFFFFF.FFFFFFFF.FFFFFFFF.F
row status: active

But when I issue the command "show snmp view" the view ViewDoesNotExist is not listed.

So I'm still a bit confused.

Best regards,

Johannes

[Mark Malone]

You could have a software issue there in software if your able to write to a read only view under fault settings , im on denali on 16.3.7 on 36s , so i cant replicate it to test unfortunately