What network troubleshooting steps should I take when encountering SAP GUI 750 logon balancing error 88?

First, ping the message server hostname/IP address to confirm basic network connectivity. Then, use `tracert` (or `traceroute` on non-Windows systems) to identify any network hops where the connection might be failing. Check for firewall rules blocking traffic on the SAP gateway port (typically 3300-3399). Also, verify DNS resolution is working correctly for the message server hostname.