Wifi - GE 845 Instruction Manual

CHAPTER 4: SETPOINTS

WiFi

NOTE:
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
WiFi refers to Wireless Local Area Networks (WLANs) that are based on the 802.11 set of
standards. WLANs are essentially providing Local Area Network (LAN) type of connectivity
but without the need of cables, which makes them more convenient for use in limited
spaces. WiFi works on top of the TCP/IP stack, the same as Ethernet. The signal strength
and its range is determined by the wireless device's antenna technology and standard, the
best being IEEE 802.11n.
WiFi defines two modes of operation, namely ad-hoc, used for small deployments, and
infrastructure mode, which supports more robust types of security and better capabilities
for centralized management. The infrastructure mode requires an access point (AP).
Devices operating in this mode pass all data through the AP.
The WiFi module integrated on the 8-Series products conforms to IEEE 802.11b/g/n
standards. The 8-Series devices operate in infrastructure mode. Security is optional, but
enabled by default and it is advisable that it is left on, as wireless traffic is very susceptible
to cyber-attacks.
The security technology used is WPA2 (Wireless Protected Access version 2), based on the
IEEE 802.11i standard for data encryption. WPA2 is a second version of WPA technology,
designed to solve known security limitations found in one of the encryption algorithms
used by WPA, namely TKIP (Temporal Key Integrity Protocol). WPA2 uses CCMP (Counter
Mode with Cipher Block Chaining Message Authentication Code Protocol), which provides
an enhanced data cryptographic encapsulation mechanism based on AES (Advanced
Encryption Standard). CCMP makes WPA2 much stronger and secure than its
predecessors, WPA and WEP.
Several forms of WPA2 security keys exist. The 8-Series supports WPA2 PSK (Pre-Shared
Key), which utilizes 64 hexadecimal digits. The key may actually be entered as a string of
64 hexadecimal digits or as a passphrase of 8 to 32 printable ASCII characters. For user
convenience, the settings accept the key in the form of a passphrase. Internally the ASCII
passphrase is used for deriving a 256-bit key.
WiFi Settings
The following are the WiFi network settings for the 8-Series product. Only an Administrator
has the rights to change them.
Path:
Setpoints > Device > Communications > WiFi
WiFi Enable
This setting switches WiFi functionality on/off. By default WiFi is enabled in the basic
offering, but it is disabled in software options that offer CyberSentry.
WiFi IP Address / Subnet Mask
The default IP address is 192.168.0.x, where x is calculated as:
X = (modulo 242 of the last 3 digits of the serial number) + 12
Example: A unit has a serial number of MJ3A16000405, the default IP address would be
192.168.0.175 (where 405 mod 242 = 163 + 12 = 175).
This is to ensure uniqueness of the default IP address for all 8 Series devices present on one
wireless network and it creates a usable address space from 192.168.0.12 to 192.168.0.253
for 8 Series devices.
From the remaining range of unicast addresses 192.168.0.1 to 192.168.0.253, at least two
are going to be used for the AP and a laptop installed with the EnerVista software, which
will be used to configure the 8 Series devices. The AP should be configured with the
address 192.168.0.1 and mask 255.255.255.0 and have DHCP enabled with a DHCP range
from 192.168.0.2 to 192.168.0.253. This allows laptops, iPads and any other devices to
connect to the local network without the need to statically configure their own IP address
and mask.
WiFi GWY IP Address
The setting specifies the address of the access point AP which the 8 Series device uses for
communicating over WiFi.
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