SNMP "bad community name" errors after upgrade

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Hello,

I upgraded a Summit X460-48p from version 15.1.4.3 to 16.1.3.6.

After the upgrade, our monitoring servers (cacti, zabbix) are not able to get SNMP information from the switch anymore (SNMP v2c, readonly community).

In the switch logs, i see a lot of error messages "<Warn:SNMP.Master.AuthFail> snmpMaster: Login failed through SNMPv1/v2c - bad community name (x.x.x.x)" with the IP address of the monitoring servers.

Except the upgrade, nothing has changed in the configuration of the switch and the monitoring servers.

I have compared the configuration of the upgraded switch with another switch (not upgraded yet), i see some minor differences, but nothing obvious that could explain the SNMP failures.

I also checked this post (https://community.extremenetworks.com/extreme/topics/snmp-read-problems-bad-community-name-since-xos...) but it seems i don't have the same problem, as my configuration still has the "configure snmpv3 add user" commands

Maybe someone in the community has already experienced this issue.

Thanks for your help.
Best regards
Gabriel
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Gabriel

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Posted 1 year ago

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OscarK, ESE

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If you recreate the snmp user, does it work ? 
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Taykin Izzet , Employee

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Gabriel, the message reports a bad v1/v2 community. The following commands will help determine which community's are being used:

show snmpv3 community
show conf "snmp" detail | inc community
show management

As mentioned, try to delete and recreate the communities. the following articles will help:

https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-remove-default-SNMP-credentials-in-...
https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-configure-the-SNMP-community-names 

Also, review the show management outputs counters for Authentication Errors, and or, Errors. It may also be worth trying to remove the device from the NMS/MiB Browser and re-adding it there too.
(Edited)
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Bernhard Gruenwald

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Hello,

I had a similar Problem after upgrade from 16.x to 22.1. The snmpv3 users have the Row Status "NotInService" (show snmpv3 user). Also I can not create new snmpv3 users.

This wrote GTAC:

This is a known issue and is documented in xos0066086 "User-defined SNMPv3 users do not work after upgrading to ExtremeXOS 22.1 if the SNMPv3 default-users were disabled using the command disable snmpv3 default-user in ExtremeXOS 21.1 or earlier." This happens when the default SNMPv3 user and group are disabled in 21.x or earlier, an upgrade performed to 22.x and the switch is rebooted in 22.x. This happens because these groups and user have been removed in 22.x along with the associated variables. The work around is to reboot back in 21.x, enable the default-user and default-group, run a fresh upgrade to 22.x, reboot into 22.x and disable them from there. The second workaround is to unconfigure the switch and reconfigure it while in 22.x. A fix will be available in 22.2.1

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Gabriel

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Hi,

Thanks for answering fast.

I tried to delete and recreate the communities but it doesn't seem to work.

I also tried to create an simple communitity for testing. I did it both on a version 15.1.4.3 switch and a version 16.1.3.6 switch :

#configure snmp add community readonly test
#enable snmp community test

then from my monitoring server i try : "snmpwalk -v 2c -c test X.X.X.X 1.3.6.1.2.1.2.2.1.8"
The v15 switch answers, but not the v16 switch
On the version 16 switch i still have the messages "bad community name"

Best regards,
Gabriel
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Taykin Izzet , Employee

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Could you check the users and mib-views? They may need to re-added/enabled per this article:

https://gtacknowledge.extremenetworks.com/articles/Solution/SNMP-communication-lost-after-EXOS-upgra...

configure snmpv3 add mib-view "defaultUserView" subtree 1.0/00 type included
configure snmpv3 add mib-view "defaultAdminView" subtree 1.0/00 type included
configure snmpv3 add mib-view "defaultNotifyView" subtree 1.0/00 type included
enable snmpv3 default-group
enable snmpv3 default-user
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Gabriel

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Hello,

It works !
Thanks a lot for the help

Best regards,
Gabriel