Peter, can you please reply with your configuration (with any sensitive information removed), as well as the config you're attempting to add that causes the issue? Thanks
They're using SolarWinds to poll the Adtran every 30 seconds due to fax issues happening around 45 seconds. As soon as they enable the polling on the SolarWinds it crashes the VLAN.
They didn't install any of the modules on the Adtran, perhaps that's where the problem is? All they did was set up the community string on the Adtran and start polling (it does connect).
30 seconds is a bit aggressive. A few things to check:
Make sure that the Solarwinds application isn't doing a full walk every 30 seconds. It should only poll the parameters of interest and maybe do a full walk daily in off-hours to pick up any new/changed OIDs.
Configure SNMP as a read-only string with an access-list only allowing your monitoring server(s) access, not the Internet at large.
ip access-list standard snmp-access
permit host 192.168.10.10
permit host 192.168.10.20
snmp-server community itsasecret RO snmp-access