Endian banner

The Status Menu

  • System status - services, resources, uptime, kernel
  • Network status - configuration of network interfaces, routing table, ARP cache
  • System graphs - graphs of resource usage
  • Traffic Graphs - graphs of bandwidth usage
  • Connections - list of all open TCP/IP connections
  • OpenVPN connections - list of all OpenVPN connections

System status

The default page that opens when clicking on Menubar ‣ Status is the System status page, which gives a quick overview of the running services, memory, disk usage, uptime and users, loaded modules, and the kernel version, each in its own box. At the top of the page, there are hyperlinks to each box. In more details, these are the information presented in each box, which are usually the output of some Linux command.

Services

The status -marked as either Stopped or Running by a red or green square- of each service installed on the Endian 4i Edge Appliance is shown here. A service might appear as stopped because the corresponding daemon or script is not enabled.

New in version 3.0.5-2015-July: The wireless status is now shown among the services.

Memory

The output of the Linux free command supplies the data shown here. All data are represented with the real amount in kilobytes, and with a bar to ease the visualisation of the memory used. The first line shows the total used RAM memory, for which is normal to be close to 100% for a long time running system, since the Linux kernel uses all available RAM as disk cache to speed up I/O operations. The second line shows the memory actually used by processes: Ideally this value should be below 80% to keep some memory available for disk caching. If this value approaches 100%, the system will slow down because active processes are swapped to disk. If the memory usage remains for long periods of time over 80%, RAM should be added to improve performances. The third bar indicates the swap usage. For a long running system it is normal to see moderate swap usage (the value should be below 20%), especially if not all the services are used all the time.

Disk usage

The output of the Linux df command shows the disk devices -phisycal disks and partitions, their mount point and the space of each disk partition. Depending on the type of the Endian 4i Edge Appliance, the data displayed in this box differ. Usually, they are:

  • The main disk /dev/hda1.
  • The data disk /dev/mapper/local-var.
  • The configuration disk, where all the Endian 4i Edge Appliance settings are stored /dev/mapper/local-config.
  • The log disk /dev/mapper/local-log.
  • The shared memory, /dev/shm/.

Note

The data disk and the log disk may grow over time, so there should be reserved enough space for them - especially the log disk. Remember also that disks shall never be full above the 95%, since this may hinder the correct working of the system.

Uptime and users

This box shows the output of the Linux w command, which reports the current time, information about how long the system has been running since last reboot, the number of console users that are currently logged into the system (though normally there should be none) and the system load average for the past 1, 5, and 15 minutes. Additionally, if any console user is logged into the system, some information about the user is displayed (like the remote host from which she is logged in or what is she doing). More details can be found on the w(1) manual page.

Loaded modules

The output of the Linux lsmod command. It shows the kernel modules currently loaded into memory. This information should be useful to advanced users only.

Kernel version

The output of the Linux uname -r command, which shows the current kernel version.

Network status

This page contains several information about the running state of the network interfaces. Four boxes are present on the page, and, like for the System status, hyperlinks are provided at the top of the page for a quicker access. The boxes contain the following information, representing the output of different shell commands.

Interfaces

The first box reports the output of the ip addr show command which provides for each network interface the associated MAC address, IP address, and additional communication parameters. The active interfaces are highlighted with the colour of the zone they are serving. The interface can be an ethernet interfaces, a bridge, or a virtual device.

NIC status

The running configuration and capabilities of each of the NIC are shown here. Each interface is highlighted with the colour of the zone it is serving and is labelled as [Link OK] to indicate that it is working. Interfaces that are not used are labelled with ‘[NO Link]’. The command providing the output is ip link show.

Routing table entries

The kernel routing table, as provided by the route -n command. Typically, there should be one line per active interface, which correctly routes the traffic within the zones served by the Endian 4i Edge Appliance, plus a default route (recognisable by the 0.0.0.0 Destination field) that allow the traffic to reach the Internet.

ARP table entries

The last box shows the output of the arp -n command and shows the ARP table, i.e., a table containing the MAC address associated to each known IP address in the local network.

System graphs

Changed in version 2.5: Disk graphs.

The graphs displayed in this page present the usage of resources during the last 24 hours: CPU, memory, swap, and disk usage, each accompanied with a legend of the data included in the graph, their associated colour, and a summary of the maximum, average, and current percentage of use. Moreover, a message informs of the time and date of the last update to the graphs, which matches the last access to the page.

When clicking on one of the graphs, a new page will open, with summaries of the usage graphs for the last day, week, month, and year. In these pages, a click on the BACK button allows to return to the previous page.

Note

The nan (short for “Not A Number”) string that may appear in the summaries designate that there are not enough data to calculate the usage of the selected resource. It can appear for example in the “per year usage” when the Endian 4i Edge Appliance is used for only a few weeks.

CPU graph

In this box is shown the CPU usage per day of the Endian 4i Edge Appliance, measured in percentage of the CPU time used by the various processes. The output is provided by the top command. Different colors are used to denote the type of running processes:

  • White - idle, i.e., time the CPU is not used by any process.
  • Green - nice processes, i.e., user processes which have changed their default priority.
  • Blue - user processes with default priority.
  • Orange - time spent by the CPU waiting for I/O tasks to complete.
  • Red - system (kernel) processes
  • Pink - softirq, i.e., the time spent for software interrupts
  • Brown - interrupt, i.e., is the time spent for hardware interrupts
  • Black - steal meaningful only if running as a virtual machine, is the time used by the hypervisor to run the VM.

Memory graph

This graph shows the memory usage during the last 24 hours. The following colours are used to denote the types of memory:

  • Green - unallocated memory, that can be allocated to new processes.
  • Blue - cache memory, copy of recent data used by processes.
  • Orange - buffer memory, a temporary portion of memory that stores data to be sent to -or received from- external devices.
  • Red - used memory.

Swap graph

The usage of the swap area, located on the hard disk, is displayed in this box.

  • Green - unallocated swap.

  • Blue - cached swap.

  • Red - swap space used.

    See also

    A good page that clearly describes the linux memory management is here (also available in Italian).

Disk usage graph

Graphs showing the usage of the disk are split into four boxes, each showing the usage of a partition. In each of them, the green colour shows the free space, while the red colour shows the disk space used.

Changed in version 2.5: Disk graphs has been split into four Disk usage graph boxes.

The four boxes show the free and allocated space in the four hard disk’s partitions: Main disk, configuration disk, log disk, and data disk. For each of them, those colours are used.

  • Green - space available.
  • Red - space used.

In older 2.5 Endian 4i Edge Appliance, the disk graph was slightly different, since the data shown was not the disk usage, but the hard disk accesses, denoted by two colours:

  • Blue is used to show sectors read per second on the hard disk.
  • Green is used to show the sectors written per second on disk.

Traffic graphs

This page contains the traffic graphs for the last 24 hours, divided by zone. Hence, depending on the zones enabled and configured, this page will contain 2, 3, or 4 boxes, each with one graphs. Like for the System graphs, the graphs are accompanied with a legend of the data displayed:

  • Green - the outgoing traffic.
  • Blue - the incoming traffic

Below the graphs, also the summary of the average, maximum, and current amount of data transmitted and received is displayed and updated in real time.

When clicking on one of the graphs, a new page will open, with summaries of the data flown through the Endian 4i Edge Appliance for the last day, week, month, and year. The data shown are the same in all the graphs: Incoming and outgoing traffic in blue and green respectively. In

Hint

To go back to the page with all the zone’s graphs, click on the BACK hyperlink on the bottom of the page.

Connections

This page shows a table containing the list of current connections from, to, or going through the Endian 4i Edge Appliance. The data shown here are devised by the kernel conntrack table. The following colours are employed in the table and used as the background of the cells in the table to denote the source and destination of the connection.

  • Green, red, orange, and blue are the zones governed by the Endian 4i Edge Appliance.
  • Black is used for connections involving the firewall, including daemons and services, like e.g., SSH or web accesses).
  • Purple shows connections using VPN or IPsec.

The data displayed in the table are the following.

Source IP
The IP from which the connection has originated.
Source port
The port from which the connection has originated.
Destination IP
The IP to which the connection is directed.
Destination port
The port to which the connection is directed.
Protocol
The protocol used in the connection, which is typically tcp or udp.
Status
The current status of the connection, meaningful only for TCP connections. They are defined in RFC 793, significant states are ESTABLISHED (connection is active) and CLOSE (no connection).
Expires
How long will the connection remain in that particular status.

Hint

The page refreshes automatically every 5 seconds.

Each IP address and each IP port in the table can be clicked to obtain useful information. Clicking on the IP address will launch a whois query that will display who the owner of the IP address is and where it is located. Clicking on the port number will open the Internet Storm Center web page, with information about the port (i.e., the purpose for which it is used) and about which services or malware (e.g., Trojans, viruses) may exploit that port and the number of attacks received on those ports by various servers worldwide.

VPN connections

Changed in version 3.0: The box displays not only OpenVPN users, but also those connected using IPsec.

When yon the Endian 4i Edge Appliance there are OpenVPN or IPsec servers running, this page shows the connected users, along with the service they rely on for the connection (OpenVPN, L2TP, IPsec Xauth), the time stamp since they are connected, and the possible actions that can be carried out. Currently, only to disconnect the user.