Communication between the cluster appliances is called Heartbeat. Through heartbeat, cluster appliances constantly communicating HA status information to make sure that the cluster is operating properly. Heartbeat is exchanged every 2 seconds.
High Availability (HA)
High Availability feature provides hardware failure protection to the two identical Cyberoam Appliances against power supply, hard disk, or processor to maximize network uptime and ensure uninterrupted access. In the event of the failure of the Primary Cyberoam Appliance, the Secondary Cyberoam Appliance takes over to process the network traffic.
Hyper Text Transfer Protocol (HTTP)
HTTP is a standard transmission protocol used to transmit hypertext files across the Internet. Web servers and browsers communicate with each other HTTP.
Hyper Text Transfer Protocol Secure (HTTPS)
A TCP/IP protocol that is used by World Wide Web servers and Web browsers to transfer and display hypermedia documents securely across the Internet i.e. a secure version of HTTP which encrypts data. In other words, it is HTTP exchanged over an SSL encrypted session.
IMAP (Internet Message Access Protocol) is an Internet standard for the reading and manipulation of e-mail messages stored on a server. Messages are stored on a remote server. An IMAP e-mail client running on a local computer then contacts the server and uses IMAP to allow the user to see and manipulate their e-mail messages and mailboxes. IMAP differs from the common Post Office Protocol (POP) in that it allows the user to store messages on the server and manipulate them from their e-mail client, rather than having to download the messages and manipulate them on their local computer.
The numerical address of a computer or a web page. Internet protocols recognize a specific machine by this address and use DNS to translate from the IP address to the domain name.
LAN (Local Area Network) is a group of computers connected by a network, such as that in a single office, building or company.
An email client is a computer program that is used to read and send e-mail. Protocols supported by email clients include POP3 and IMAP. IMAP is optimized for storage of e-mail on the server, while the POP3 protocol generally assumes that the e-mail is downloaded to the client. The SMTP protocol is used by most email clients to send e-mail.
A mail server also called a mail transfer agent or MTA is a computer devoted to sending, receiving and storing mail. The mail client (the program you use to get your e-mail) connects to the mail server and retrieves any messages that are waiting for you.
Perfect Forward Secrecy (PFS)
It becomes difficult for a network intruder to get the big picture if keys are changing and they have to keep cracking keys for every negotiation. This is achieved by implementing PFS. By selecting PFS, new key will be generated for every negotiation and a new DH key exchange is included. So every time intruder will have to break yet another key even though he already knows the key. This enhances security.
Pharming involves Trojans & worms that attack the Internet browser address bar. When users type in a valid URL they are redirected to the criminals' websites instead of the valid website.
Phishing refers to the stealing of personal identifiers such as Pin numbers, Credit card numbers, and passwords via a spoof web site or email. It is baiting the end users by playing on their fear and greed.
An authentication mechanism whereby the key is used in encryption is exchanged before hand/prior to negotiation with another system.
Preshared key authentication is the process by which two systems prove their identity to each other where each system encrypts some unpredictable, arbitrary data with a key that has been exchanged beforehand. If they can successfully decrypt the message, it is assumed that the sender is valid.
A single shared key is used for encryption and decryption. The data is encrypted by a key and send to the recipient over the Internet. At the receiving end, the data is decrypted with the exact same key that was used for encryption.
POP (Post Office Protocol 3) is a communication protocol used by email client programs for receiving e-mail from a Mail Server. Your e-mail is stored on a server until you check your mail and download messages on your computer.
POP3 is a commonly implemented method of delivering email from the mail server to the client machine. Other methods include IMAP and Microsoft Exchange.
In other words, POP is an protocol for incoming mails.
Cyberoam appliance configured in the HA cluster to process network traffic. Under normal operating conditions, it operates in an ACTIVE mode.
Public key authentication uses two keys – public key available to anyone and a private key held by only one individual. The sender encrypts the data with the recipient’s public key. Only the recipient can decrypt the data, being the only one who possesses the corresponding private key.
RADIUS stands for Remote Authentication Dial In User Service and is a protocol for allowing network devices to authenticate users against a central database.
Cyberoam appliance which does not process the network traffic but is configured in the HA cluster. Under normal operating conditions, it operates in ACTIVE-STANDBY mode.
Serpent is a 128-bit block cipher i.e. data is encrypted and decrypted in 128-bit chunks variable key length to be either 128, 192, or 256 bits. The Serpent algorithm uses 32 rounds, or iterations of the main algorithm.
Serpent is faster than DES and more secure than Triple DES.
Simple Network Management Protocol (SNMP)
Simple Network Management Protocol is used as the transport protocol for network management. Network management consists of network management station/manager communicating with network elements such as hosts, routers, servers, or printers.
SMTP (Simple Mail Transfer Protocol) is a protocol for sending e-mail messages between servers. Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP.
The SMTP protocol can only be used to send emails, not to receive them. In other words, SMTP is a protocol for outgoing mails.
SMTP is generally used to send messages from a mail client to a mail server; this is why you need to specify both the POP or IMAP server and the SMTP server when you configure your e-mail application.
Spam is any unwanted email communications that you receive. It is usually in the form of advertising material that is sent to a large number of people at one time.
The process of sharing the cluster configuration, routing table and individual cluster appliance status between Cluster appliances (HA peers).
Twofish is a symmetric key block cipher with a block size of 128 bits and key sizes up to 256 bits.
User Datagram Protocol
UDP is the Layer 4 (Transport Layer) protocol that is used primarily for broadcasting messages and other small amounts of data throughout the network. Unlike TCP, UDP is a low-overhead i.e. does not use much bandwidth or CPU, unreliable, connectionless protocol that runs on IP networks. Unreliable means that no checking is performed to ensure packets reach their destination.
Virus is a self-replicating, malicious code that attaches itself to an application program or other executable system component and leaves no obvious signs of its presence and usually capable of causing great harm to files or other programs on the same computer.