@reboot /usr/sbin/ethtool -K eth0 tx off > /dev/null @reboot /usr/sbin/ethtool -K eth0 gso off > /dev/null @reboot /usr/sbin/ethtool -K eth0 rxvlan off > /dev/null @reboot /usr/sbin/ethtool -K eth0 gro off > /dev/null @reboot /usr/z1090/bin/safenet_daemons_restart reboot > /dev/null */11 * * * * /usr/z1090/bin/safenet_daemons_restart > /dev/null 

The last two lines are created during zPDT installation. The iptables  and ethtool  commands have been described earlier. The “eth0” operand in many of the lines is the name of our ethernet port; the name might be different on your system. The “3270” operand is the port number for aws3274 that is specified in our devmap; you might use a different port. Our example was used with openSUSE; you might need adjustments for other Linux distributions. 

The effect of this table is that, after booting Linux (with the firewall enabled), starting zPDT, and IPLing z/OS, we can connect z/OS to external internet sites (due to the nat  operation) and experience very reasonable ethernet transfer rates. (We have noticed that the gro function is sometimes turned back on automatically; we do not know why this happens.) 

If you are not familiar with crontab customization, please do a little research before attempting changes to it. The crontab lines for the safenet daemons must not be altered. 

## firewall-cmd use 

The firewall-cmd options entered dynamically can be made permanent with the following command: 

# firewall-cmd --runtime-to-permanent 

or the --permanent option  can be added when the firewall-cmd commands are entered. 

Important:  Do not blindly copy our examples. You must understand your networking environment and your networking goals and adjust our examples accordingly. The iptables and firewall-cmd commands and nat functions discussed here might not be appropriate for your environment. 

## 7.10 Useful z/OS networking commands 

The following commands might be useful when working with LAN devices: 

GLYPH<SM590000> z/OS operator commands: 

D U,,,dddd,nn dddd = address, nn = number to display D M=DEV(dddd) provides path status D M=CHP display all CHPIDs defined to z/OS D IOS,MIH display current MIH values S ETIOS MIH,DEV=E201,TIME=00:30 example of setting MIH 

GLYPH<SM590000> TSO commands: 

NETSTAT DEV display all devices and links NETSTAT HOME display home address NETSTAT GATE display gateway addresses NETSTAT CONN display connection status TRACERTE ipaddress PING ipaddress (Issue ALLOC DD(SYSTCPT) DA(*)  before TRACERTE or PING for more data.) 

GLYPH<SM590000> VTAM commands: 

