Redirections issues TSE - Cisco SMB SA 520

Question

Hello,
I'm having troubles on a SA 520 router in Load Balancing mode (WAN1 with ADSL router, WAN2 with Wimax modem).
It seems like Load Balancing working pretty well but some terminal server connections are having stability issues. These sessions are 4 with 4 customs ports forwarding to 4 different computers.
One of them works well, others not and one doesn't work at all. 4 firewall's rules (8 in fact, 1 for each WAN) are made in the same way...
For the test connection (the one which worked well), I had to disable some "Attacks" features to improve its stability (like TCP Flood protection).
What would you advice to fix these problems and make TSE connections work well ? I forgot to mention that they work well with the ADSL router only with simply firewall rules.
Thanks in advance for you further help !

Answer 1

Hello,
We've made many many tests to better understand the problem. Firmware is now the last recent version : 1.1.21
Each test is realised with following settings :
- 4 remote access connections on a single WAN configuration
- protocol bindings for each
- dedicated WAN = wimax
- optional WAN = adsl behing adsl router
First test (single WAN)
With WAN1 or WAN2 working alone, with protocol bindings and redirections well set, everything's ok. Remote connections are always working greatly and don't suffer of disconnections.
Second test (double WAN)
With both WAN activated, the situation isn't the same. I've tried to test both redirections on WAN1 or WAN2 (with protocol bindings). Remote connections work randomly, a connection can work and disconnects a few minutes later without possibility of reconnection.
An interesting thing to know is that HTTP/HTTPS and some other services defined in the same way (with protocol bindings) work very well. It seems that the problem only affects inbounds connections and custom services (on custom ports to connect on local computers).
Third test (double WAN + capture packets)
Attached files are the result of capture. Redirections + protocol bindings of remote connections are set on WAN1. WAN2 capture shouldn't contain any traffic on ports used by redirections (2222/4444/4747/5679). Something may going wrong with that, as if the router redirect inbound connection on the local computer throught WAN1 and use WAN2 to get out.
I hope you'll understand the problem, sorry for my bad english. I'm avalaible to answer questions to give more details.
Thank in advance for further help.