User Guide
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is allowed to access resources located on the protected side of the network.
Port Mirroring
Network Engineers or Administrators use port mirroring to copy traffic from multiple ports to the mirroring
destination port for analyzing and debugging data or diagnosing errors on a network. It helps the
administrator keep a close eye on network performance and will alert him when problems occur.
(Mirroring traffic here is equivalent to copying traffic.) It can be used to mirror either inbound or outbound
traffic on single or multiple interfaces.
LACP
Within the IEEE specification the Link Aggregation Control Protocol (LACP) provides a method to control
the bundling of several physical ports together to form a single logical channel. In this way, link bandwidth
is increased, available redundancy is raised and transmission quality is also enhanced.
ACL
An ACL (Access Control List) contains entries that specify individual user or group rights to specific
system objects such as programs or processes. These entries are known as access control entries
(ACEs). Each accessible object contains an identifier to its ACL. The privileges or permissions determine
specific access rights. On some types of proprietary computer hardware (in particular routers and
switches), an Access Control List refers to rules that are applied to port numbers or IP Addresses that are
available on a host or other layer 3, each with a list of hosts and/or networks permitted to use the service.
Both individual servers as well as routers can have network ACLs. Access control lists can generally be
configured to control both inbound and outbound traffic, and in this context they are similar to firewalls.
DHCP
The Dynamic Host Configuration Protocol (DHCP) is a network protocol that is used to configure network
devices so that they can communicate on an IP network. A DHCP client uses the DHCP protocol to
acquire configuration information, such as an IP address, a default route and one or more DNS server
addresses from a DHCP server. The DHCP client then uses this information to configure its host. Once
the configuration process is complete, the host is able to communicate on the Internet. The DHCP server
maintains a database of available IP addresses and configuration information, ensuring each IP address
assigned is unique on the network. A valid IP address (lease time has not expired) will never be allocated
to a second client. The IP pool is maintained by the DHCP server itself instead of a network administrator.
ARP
Address Resolution Protocol (ARP) is a protocol used for resolution of network layer addresses into link
layer addresses, such as Ethernet addresses. In order to communicate with a neighboring host, the host
needs to first know its neighbor's IP address. It also needs to know its neighbor's MAC address by
sending a broadcast ARP message requesting an answer for the neighbor's IP address.
DoS
A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt
to make a machine or network resource unavailable to its intended users. Perpetrators of DoS attacks
typically target sites or services hosted on high-profile web servers such as banks, credit card payment
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