Thank you for the response Harald. I do not have everything set up to locally recreate the build. I used apt to update but the change is not getting pulled in yet.
However, I get what you are saying about the ports, and I had intentionally set '--server-port 9999' to overcome a different problem but I just managed to move it around. Therefore based on your comments I went back to the defaults. Here I will exactly explain the setup and IP addresses and then show you the output I get when using default values. Ubuntu 20.04 VM running remsim-server, remsim-bankd. Single cardreader mounted. VM IP address = 192.168.70.241 RPi w/ Rasbian lite image. ST2 board attached and cardem FW loaded. RPi IP address = 192.168.70.218 On the VM I manually start the server and bankd in terminals to monitor stderr slotmapping command for reference @ubuntu:~$ python3 remsim-apitool.py -m 1 0 1 0 @ubuntu:~$ sudo osmo-remsim-server 40918 DLINP NOTICE input/ipa.c:283 0.0.0.0:9998 accept()ed new link from 127.0.0.1:41729 40918 DLINP NOTICE input/ipa.c:283 0.0.0.0:9998 accept()ed new link from 192.168.70.218:41267 40926 DSLOTMAP INFO ../slotmap.c:135 Slot Map B(1:0) <-> C(1:0) added 40926 DMAIN INFO rest_api.c:333 Slot Map B(1:0) <-> C(1:0) state change: NEW -> NEW 40926 DMAIN INFO rest_api.c:339 Slot Map B(1:0) <-> C(1:0) state change: NEW -> NEW 40918 DMAIN INFO rspro_server.c:716 Event FD arrived, checking for any pending work 40918 DMAIN INFO rspro_server.c:391 Slot Map B(1:0) <-> C(1:0) state change: NEW -> UNACKNOWLEDGED 40918 DMAIN INFO rspro_server.c:363 Slot Map B(1:0) <-> C(1:0) state change: UNACKNOWLEDGED -> ACTIVE @ubuntu:~$ sudo osmo-remsim-bankd -b 1 -n 1 40921 DMAIN INFO bankd_pcsc.c:105 PC/SC slot name: 1/0 -> regex 'OMNIKEY AG CardMan 3121 \(OKCM0012007091219038212815383974\) 00 00' 40921 DRSPRO INFO ../rspro_client_fsm.c:307 RSPRO_CLIENT(server){REESTABLISH}: Creating TCP connection to server at localhost:9998 40921 DLINP NOTICE input/ipa.c:128 localhost:9998 connection done 40921 DRSPRO NOTICE ../rspro_client_fsm.c:127 RSPRO_CLIENT(server){REESTABLISH}: RSPRO link to localhost:9998 UP 40922 DBANKDW INFO bankd_main.c:442 [000 INIT] Changing state to INIT 40922 DBANKDW INFO bankd_main.c:442 [000 INIT] Changing state to ACCEPTING 40921 DSLOTMAP INFO ../slotmap.c:135 Slot Map B(1:0) <-> C(1:0) added The command on the RPi (no manual server port included this time) pi@raspberrypi:~ $ sudo osmo-remsim-client-st2 --usb-vendor 1d50 --usb-product 60e3 --usb-path 1-1.3 --usb-interface 0 --usb-config 1 --usb-altsetting 0 --client-id 1 --client-slot 0 --server-ip 192.168.70.241 DRSPRO INFO ../rspro_client_fsm.c:307 RSPRO_CLIENT(server){REESTABLISH}: Creating TCP connection to server at 192.168.70.241:9998 DLINP NOTICE simtrace2_api.c:271 [0] <= osmo_st2_cardem_request_config(features=00000001) DLINP NOTICE input/ipa.c:128 192.168.70.241:9998 connection done DRSPRO NOTICE ../rspro_client_fsm.c:127 RSPRO_CLIENT(server){REESTABLISH}: RSPRO link to 192.168.70.241:9998 UP DRSPRO INFO ../rspro_client_fsm.c:307 RSPRO_CLIENT(bankd){REESTABLISH}: Creating TCP connection to server at 127.0.0.1:9999 DRSPRO NOTICE ../rspro_client_fsm.c:127 RSPRO_CLIENT(bankd){REESTABLISH}: RSPRO link to 127.0.0.1:9999 DOWN DRSPRO ERROR ../rspro_client_fsm.c:297 RSPRO_CLIENT(bankd){REESTABLISH}: Event SRVC_E_KA_TERMINATED not permitted DRSPRO INFO ../rspro_client_fsm.c:302 RSPRO_CLIENT(bankd){REESTABLISH}: Destroying existing connection to server DRSPRO INFO ../rspro_client_fsm.c:307 RSPRO_CLIENT(bankd){REESTABLISH}: Creating TCP connection to server at 127.0.0.1:9999 DRSPRO NOTICE ../rspro_client_fsm.c:127 RSPRO_CLIENT(bankd){REESTABLISH}: RSPRO link to 127.0.0.1:9999 DOWN ^C pi@raspberrypi:~ $ When I saw the port 9999 in there and I kept getting this error, I tried to switch the client to manually use :9999. It seemed to get closer to working because bankd reported it was opening the card reader. You comments prove that was not the usage I needed. Thank you for feedback, I know I must be close. Best, Paul