The stats screen is reporting the DX connections to the target server. As the DX could have up to to 20 active client requests at a time, the DX could open up more than 20 connections to the target server if previously opened connections were not fully closed. Note also that by default the DX maintains 6 standing connections to the server, so you should always see a minimum of 6 target server connections. Basically, as the DX is proxying the client requests there is not a direct correlation between the amount of client connections and the target server connections, especially if multiplexing of the client requests is occurring (enabled by default by 'set cluster <name> connbind enabled')
SNMP will give more detailed statistics on client-side connections. The MIB is available via the WebUI at the bottom of the page of Admin ->SNMP where the 'Download MIBs' dropdown menu is. The DX-STATS-MIB has per cluster statistics:
I loaded this MIB in a MIBbrowser and found the OID for these variables starts with 126.96.36.199.4.1.6188.8.131.52.1, so I copied the DX MIBs to the default MIB directory on a FreeBSD box (/usr/local/share/snmp/mibs) and then do the following snmpwalk:
$ snmpwalk -v2c -m +DX-STATS-MIB -c public 172.26.31.206 184.108.40.206.4.1.6220.127.116.11.1
We have 2 DX 3280s and I'm unable to get stats off of them. When I snmpwalk the clusterStats OID it shows me only the names of my clusters and if they're Up. I don't get any statistics that the MIB shows me I should (and what you see in your example below). Is there some additional DX magic that has to happen in order for the statistics to appear in SNMP?
I think the problem is that you are using SNMPv1 for the snmpwalk rather than SNMPv2c. v1 can only read 32 bit counters while v2c supports 32 and 64 bit counters. With snmpwalk you use the -v switch to set which version to use, so for SNMPv1 I see: