We have found a very small number of routers will send a blank SNMP reply if more that a certain number of SNMP OIDs are requested simultaneously.
You can adjust the number of OIDs that PeakHour will send in a single request using the following steps:
In Terminal, enter the following command:
Paddle (direct) version
defaults write com.digitician.PeakHour4 SnmpMaxOidsPerQuery 1
Mac AppStore version
defaults write ~Library/Containers/com.digitician.peakhour4/Data/Library/Preferences/com.digitician.peakhour4.plist SnmpMaxOidsPerQuery 1
If you're unsure which version of PeakHour you have, see here: How do I tell which distribution of PeakHour I have?
If this worked, your router should respond to PeakHour normally.
Reducing the number of simultaneous OIDs sent increases the amount of work both PeakHour and your router have to do. For optimal performance, you may want to increase the number to find the 'breaking point' for your router and keep the value to just under that.