I would check to see if agents are present on the agent machines by checking
dsmver --> make sure all the same version
is cam installed ? run camstat to verify and if so can you camping the Scalability server by IP address, hostname and FQDN ?
Can the Scalability server camping the agent ?
on the agent machine if installed run these commands and see if that helps populate the host object into the DSM Explorer
caf setserveraddress <Scalability server hostname>
caf register all
caf start amagent -args /rescan_inventory /rescan_software /collect <if you are using asset agents>
Then check on the agent side for the DSM\logs\TRC_CF_REGISTER_0.log and make sure you see a good registration take place.
Please also make sure you are not seeing reverse proxy messages in the Domain Managers and Scalability servers cam log located in the %CAI_MSQ%\logs
if you see many reverse proxy messages and you don't have a cam.cfg file present then follow technical document # TEC539203 .
NOTE: dont add disable_porxies=yes if you have entries in the #ROUTING section as that setting will be ignored.
Hope this is helpful and let us know what happens so we can assist you further.