Having a problem and need asssistance. I have a 5505 that I have two systems attempting to communicate with each other via one VLAN interface on the ASA. The systems can ping each other but when they attempt to do TCP connections between them (Ex. RDP) it fails. In the log, it shows this:
%ASA-6-106015: Deny TCP (no connection) from 172.26.0.23/3389 to 192.168.1.2/1141 flags RST ACK on interface inside
Packet tracer works fine everytime.
Sanatized config attached
Seeing you configuration,I could see these settings.
1. inside (vlan1): 172.26.0.0/24
2. dmz(vlan3): 192.168.1.64/26
3. asa-inside ip: 172.26.0.1
3. router-ip: 172.26.0.11
4. network behind router: 192.168.1.0/28
Now, Let me explain what is happening:
1. U initiate RDP from host 1.2 to host 0.23
2. router sends the traffic to host 0.23 via interface 0.11
3. host 0.23 sends reply via its default gateway 0.1
4. ASA checks the TCP header and have ACK flag set.
5. ASA tries to find an connection slot, for established connection
6. No established connection is found and ASA can not create new conn slot, coz it is ACK packet not SYN, so drops the packet.
Resolution to problem:
Try setting your default gateway on host 0.23 to 0.11, that might work. If it didn't, set your host computers in separate zone either connected to ASA or Router.