It is normal for the attack detection SNMP alert to not contain source IP information when the SNMP alert is sent. The MIB for attack detection does not contain the source IP information. It is possible to view the attack detection source IP information on the ProxySG. The URL for attack detection blocked clients is:
https://<IP.address.of.ProxySG>:8082/ADP/blocked-clients
The URL for attack detection client statistics is:
https://<IP.address.of.ProxySG>:8082/ADP/clients