How the Balance 2500 connected to the Cisco ASA firewall ? Direct connect 2 or more cables from the Balance 2500 LAN interfaces to the CISCO ASA WAN interfaces ? Do you have the physical diagram for the setup ?
What do you mean “many problems and the link aggregation not going well between the devices” ? Do you have the actual symptoms for the issue ?
Beside that, when configuring the LACP setup, do you static down the settings below for both end devices (B2500, ASA)
- Port Speeds
- Duplex mode
I would recommend to put in a switch between Balance 2500 & CISCO ASA firewall to further investigate the issue.