Error
Error Code:
1037
SAP S/4HANA Error 1037: Unknown Hostname Connection Issue
Description
This error indicates that SAP S/4HANA cannot resolve or find the specified hostname for a server or service it is trying to communicate with. It typically occurs when the system attempts to connect to an external resource (e.g., database, web service, or another system) and the target hostname is either incorrect, misspelled, or unresolvable by the network's DNS.
Error Message
ERR_COM_UNKNOWN_HOST
Known Causes
4 known causesIncorrect Hostname Configuration
The hostname entered in SAP S/4HANA configuration settings or a related application is misspelled, outdated, or refers to a non-existent host.
DNS Resolution Failure
The Domain Name System (DNS) server configured for the network is unable to translate the provided hostname into a valid IP address.
Network Connectivity Issues
Underlying network problems prevent SAP S/4HANA from reaching the DNS server or the target host itself.
Firewall or Proxy Blocking
A firewall, proxy server, or security group is blocking the outbound connection attempt to the specified hostname.
Solutions
3 solutions available1. Verify Hostname Resolution on Application Server easy
Ensures the SAP application server can correctly resolve the hostname of the target database server.
1
Log in to the SAP S/4HANA application server (the server where SAP instances are running) via SSH or RDP.
2
Open a terminal or command prompt.
3
Use the `ping` command to test connectivity and hostname resolution to the database server. Replace `your_db_hostname` with the actual hostname or IP address of your SAP HANA database server.
ping your_db_hostname4
If `ping` fails with 'unknown host' or similar, check the `/etc/hosts` file (Linux) or the `hosts` file (Windows) on the application server for an incorrect or missing entry for the database server.
cat /etc/hosts5
If the entry is incorrect or missing, add or correct the line in the `hosts` file to map the IP address to the hostname. For example: `192.168.1.100 your_db_hostname your_db_hostname.yourdomain.com`
sudo nano /etc/hosts6
After modifying the `hosts` file, try the `ping` command again.
ping your_db_hostname7
If `ping` is successful, restart the relevant SAP instance(s) on the application server to pick up the changes.
stopsap; startsap2. Validate Database Connection Parameters in SAP System Profile medium
Ensures the database connection details configured within the SAP S/4HANA system profile are accurate.
1
Log in to the SAP S/4HANA system using SAP GUI with administrative privileges.
2
Navigate to transaction code `RZ10` (Profile Maintenance).
3
Select the instance profile for the application server experiencing the error.
4
Choose 'Display' or 'Change' to view the profile parameters.
5
Locate parameters related to database connection, typically starting with `rdisp/db_connect` or similar. Key parameters to check include:
6
`dbms/type`: Should be set to `HDB` for SAP HANA.
7
`rdbms/max_con`: Maximum number of database connections.
8
`db_connect/max_con`: Maximum number of database connections.
9
`db_connect/0/db_host`: The hostname or IP address of the SAP HANA database server. This is the most critical parameter for the 'Unknown Hostname' error.
10
`db_connect/0/db_port`: The SQL port of the SAP HANA database (e.g., 39013 for instance 00).
11
Ensure that `db_connect/0/db_host` is correctly set to the resolvable hostname or IP address of your SAP HANA database. Verify there are no typos or incorrect characters.
12
If any changes are made, save the profile and activate it.
13
Restart the SAP application server instance(s) for the changes to take effect.
3. Check Network Connectivity and Firewall Rules medium
Verifies that network paths between the SAP application server and the database server are open and not blocked by firewalls.
1
Identify the IP addresses and the SQL port of your SAP HANA database server. The default SQL port for instance `XX` is typically `3XX13` (e.g., `39013` for instance `00`).
2
From the SAP S/4HANA application server, use `telnet` or `nc` (netcat) to test connectivity to the database server's SQL port. Replace `your_db_hostname` and `your_db_port` accordingly.
telnet your_db_hostname your_db_port3
If `telnet` hangs or reports a connection refused/timeout, it indicates a network or firewall issue.
4
Consult with your network administrators to ensure that firewall rules (on the application server, database server, and any intermediate network devices) allow TCP traffic on the SAP HANA SQL port from the application server's IP address to the database server's IP address.
5
If using DNS, also ensure that DNS resolution is functioning correctly across the network. You can use `nslookup` or `dig` from the application server to verify.
nslookup your_db_hostname6
Once network connectivity is confirmed and firewalls are adjusted, re-test the SAP connection.