Archive for 'CCNA Notes' Category
Fast Ethernet
Instead of requiring campuses to invest in a completely new technology to gain increased bandwidth, the networking industry developed a higher-speed Ethernet based on existing Ethernet
standards. Fast Ethernet operates at 100 Mbps and is defined...
Ethernet (10 Mbps)
Ethernet is a LAN technology based on the Institute of Electrical and Electronics Engineers (IEEE) 802.3 standard. Ethernet (in contrast to Fast Ethernet and later versions) offers a bandwidth of 10 Mbps between end users. In its most basic form, Ethe...
Layer 3.Layer 4 .Multilayer Switching
Layer 3 Switching Devices involved in Layer 3 switching perform the following functions: ■ Packets are forwarded at Layer 3, just as a router would do. ■ Packets are switched using specialized hardware, ASIC, for high speed and low latency.
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Layer 3 Routing
Devices involved in Layer 3 routing perform the following functions: ■ Packets are forwarded between networks based on Layer 3 addresses. ■ An optimal path is determined for a packet to take through a network to the next router. ■ Packet forward...
Layer 2 Switching
Devices that forward frames at Layer 2 involve the following functions: ■ MAC addresses are learned from the incoming frames’ source addresses. ■ A table of MAC addresses and their associated bridge and switch ports is built and maintained. ...
MTU and Fragmentation
TCP/IP defines a maximum length for an IP packet. The term used to describe that
maximum length is maximum transmission unit (MTU). The MTU varies based on
configuration and the interface’s characteristics. By default, a computer cal...
FTP and TFTP
File Transfer Protocol (FTP) and Trivial File Transfer Protocol (TFTP) are two
popular file transfer protocols used in TCP/IP networks. Most end users use FTP, but
Cisco router and switch administrators often use TFTP. FTP is a TCP-based
Internet Control Message Protocol (ICMP)
ICMP is a TCP/IP protocol designed to help manage and control the operation of a
TCP/IP network. The ICMP protocol provides a wide variety of information about a
network’s status and is considered part of TCP/IP’s network layer...
Configuring NAT Overload and PAT
The ip nat inside source overload command is used to configure NAT overload. The
overload parameter is required to enable overload. Without this parameter, the
router does not perform overload, but dynamic NAT. You can use the show ip nat<...
Configuring Dynamic NAT
Dynamic NAT configuration differs from static NAT but it also has some similarities.
It requires that each interface be identified as either an inside or outside
interface but the static mapping is not required. In addition, a pool of insi...