Applies to SUSE Linux Enterprise Server for SAP Applications 15 SP4

10 Firewalling #

This chapter presents information about restricting access to the system using firewalling and encryption and gives information about connecting to the system remotely.

10.1 Configuring `firewalld` #

By default, the installation workflow of SUSE Linux Enterprise Server for SAP Applications enables firewalld.

Note: `firewalld` replaces SuSEfirewall2

SUSE Linux Enterprise Server for SAP Applications 15 introduces firewalld as the new default software firewall, replacing SuSEfirewall2. SuSEfirewall2 has not been removed from SUSE Linux Enterprise Server for SAP Applications 15 and is still part of the main repository, though not installed by default. If you are upgrading from a release older than SUSE Linux Enterprise Server for SAP Applications 15, SuSEfirewall2 will be unchanged and you must manually upgrade to firewalld (see Security and Hardening Guide).

The firewall needs to be manually configured to allow network access for the following:

SAP application
Database (see the documentation of your database vendor; for SAP HANA, see Section 10.2, “Configuring HANA-Firewall”)

Additionally, open the ports 1128 (TCP) and 1129 (UDP).

SAP applications require many open ports and port ranges in the firewall. The exact numbers depend on the selected instance. For more information, see the documentation provided to you by SAP.

10.2 Configuring HANA-Firewall #

To simplify setting up a firewall for SAP HANA, install the package HANA-Firewall. HANA-Firewall adds rule sets to your existing SuSEfirewall2 configuration.

HANA-Firewall consists of the following parts:

YaST module SAP HANA firewall. Allows configuring, applying, and reverting firewall rules for SAP HANA from a graphical user interface.
Command-line utility hana-firewall. Creates XML files containing firewall rules for SAP HANA.
If you prefer, you can configure the rule sets using the configuration file at /etc/sysconfig/hana-firewall instead of using YaST.

Important: SAP HANA MDC databases

For multi-tenant SAP HANA (MDC) databases, determining the port numbers that need to be opened is not yet possible automatically. If you are working with a multi-tenant SAP HANA database system, before you use YaST, run a script on the command line to create a new service definition:

# cd /etc/hana-firewall.d
# hana-firewall define-new-hana-service

You need to switch to the directory /etc/hana-firewall.d, otherwise the rule file for the new service will be created in a place where it cannot be used.

The script will ask several questions: Importantly, it will ask for TCP and UDP port ranges that need to be opened.

Note: Install HANA-Firewall packages

Before continuing, make sure that the packages HANA-Firewall and yast2-hana-firewall are installed.

Procedure 10.1: Using HANA-Firewall #

Make sure the SAP HANA databases for which you want to configure the firewall are correctly installed.
To open the appropriate YaST module, select Applications / YaST, Security and Users / SAP HANA Firewall.
Under Global Options, activate Enable Firewall. Additionally, decide whether to Allow Remote Shell Access (SSH).
Choose a network interface under Allowed Services on Network Interface.
Allow network services by selecting them in the list box on the left and clicking →. Remove services by selecting them in the list box on the right and clicking ←.
To add services other than the preconfigured ones, use the following notation:
```
SERVICE_NAME:CIDR_NOTATION
```
For more information about the CIDR notation, see https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing. To find out which services are available on your system, use getent services.
Repeat from Step 4 for all network interfaces.
When you are done, click OK.
The firewall rules from HANA-Firewall will now be compiled and applied. Then, the service hana-firewall will be restarted.

Finally, check whether HANA-Firewall was enabled correctly:

# hana-firewall status
HANA firewall is active. Everything is OK.

For more information, see the man page of hana-firewall.

10.3 SAProuter integration #

The SAProuter software from SAP allows proxying network traffic between different SAP systems or between an SAP system and outside networks. SUSE Linux Enterprise Server for SAP Applications now provides integration for SAProuter into systemd. This means that SAProuter will be started and stopped properly with the operating system and can be controlled using systemctl.

Before you can use this functionality, make sure the following has been installed, in this order:

An SAP application that includes SAProuter
The SAProuter systemd integration, packaged as saprouter-systemd

If you got the order of applications to install wrong initially, reinstall saprouter-systemd.

To control SAProuter with systemctl, use:

Enabling the SAProuter service: systemctl enable saprouter
Starting the SAProuter service: systemctl start saprouter
Showing the Status of SAProuter service: systemctl status saprouter
Stopping the SAProuter service: systemctl stop saprouter
Disabling the SAProuter service: systemctl disable saprouter