We have configured Site to Site VPN tunnel between Cisco PIX 506E to Cisco ASA 5510. We can see the Phase 1 and Phase 2 tunnel status as UP when issuing the commands show crypto isakmp sa and show crypto ipsec sa on both the firewall. In PIX firewall end for Phase 2 tunnel, packets are not getting decrypted (Value 0) and packets are getting encrypted. In the ASA firewall end, encryption and decryption of packets are happening.
Please let us know what will be the cause for the issue.
ASA firewall version - 8.0 (3)
PIX firewall - 6.3 (5)