diff --git a/src/sw_sup/networking.md b/src/sw_sup/networking.md
index e2e8d41..746081f 100644
--- a/src/sw_sup/networking.md
+++ b/src/sw_sup/networking.md
@@ -18,6 +18,7 @@ a-la `I can't connect, please help`.
 8. Running configured for external reference Kasli without external reference clock signal
 9. Using legacy firmware with newer hardware. ARTIQ-6 doesn't support Kasli v2.0.2 (at least without the patch mentioned in the [legacy](artiq_legacy.md) article)
 10. Some other device in your network already reserved the configured IP address.
+11. For Kasli only: the SFP adapter is inserted into the slot other than SFP0 (only upper left is supported).
 
 ## Ways to diagnose