Note: At least one DNS server must be configured
For FQDN resolution to function, at least one DNS server must be configured in
NetDefendOS. Configuring DNS servers is described in Section 3.10, “DNS”.
DNS servers might return either an IPv4 address or an IPv6 address or both. These three
possibilities are treated as follows:
• If only an IPv4 address is returned then that will be used by the ping command for the ICMP
message.
• If only an IPv6 address is returned then that will be used by the ping command for the ICMP
message.
• If both an IPv4 and an IPv6 address is available, NetDefendOS will use the IPv4 address by
default. However, NetDefendOS can be forced to use the IPv6 address with the -6 command
option. For example:
gw-world:/> ping www.example.com -6
2.6.3. The stats Command
If a serious NetDefendOS problem is suspected then the first step should be to use the CLI
command:
gw-world:/> stats
The stats command will provide a snapshot of the system and indicate the date and time of the
last system shutdown and can also indicate if there has been a serious error in NetDefendOS
operation. It should be remembered however that the buffer which stats uses is cleared by
certain operations such a reconfigure and the output will not therefore show what occurred prior
to buffer clearance.
Below is a typical example of output from the command:
gw-world:/> stats
Uptime : 7 days, 02:12:38
Last shutdown : 2014-06-17 16:05:00: Activating configuration changes
CPU Load : 4%
Connections : 23 out of 512000
Fragments : 0 out of 16384 (0 lingering)
Buffers allocated : 43280
Buffers memory : 43280 x 2636 = 111412 KB
Fragbufs allocated : 32
Fragbufs memory : 32 x 10040 = 313 KB
Out-of-buffers : 0
At the end of the Last shutdown line is the reason for the shutdown.
stats Command Output with Poll Offloading
When NetDefendOS runs on certain hardware platforms, it can make use of a technique known
as poll offloading to increase performance. With poll offloading, there are two CPU cores that are
active. One CPU core is running most of NetDefendOS's functions and the second is running the
part of NetDefendOS that handles Ethernet interface polling.
When the stats command is used with poll offloading active, the CPU Load line in the command
Chapter 2: Management and Maintenance
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