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Cisco CCNA exam Cram Sheet

Cisco CCNA exam Cram Sheet General Networking Port Numbers Port Number Layer 4 Protocol Suite Application 20 TCP FTP Data 21 TCP FTP Program 23 TCP Telnet 25 TCP SMTP 53 TCP/UDP DNS 69 UDP TFTP 80 TCP HTTP Ping Responses ! – Reply from target address . – Timeout U – Destination unreachable C – Congestion experienced I – User interrupt ? – Unknown packet type & – Packet lifetime exceeded Ethernet 5-4-3 rule – Between any 2 nodes there can only be a maximum of 5 segments, 4 repeaters and only 3 of those segments can have hosts. Loop back address –, tests

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Cisco ACL Revision

Access Control Lists (ACL) Access Control Lists are used to: Prioritise traffic Restrict or reduce updates Provide basic security Block types of traffic Access control list placement Standard ACLs – Place as close to destination as possible. Extended ACLs – Place as close to source of traffic as possible. Only one ACL per port per direction is allowed. ACL are more efficient on outbound port. If a packet does not match the ACL statement then it will be implicitly denied. Once a packet matches an ACL statement no other checks are made, it is permitted.   ACL IOS commands Standard ACLs – Used to permit or deny an e

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CCNA basic switch configuration commands

Cisco basic configuration commands (CCNA) Command descriptions switch>? The ? works here the same as in a router Used to get the list of all available commands switch>enable User mode, same as a router switch# Privileged mode switch#disable Leaves privileged mode switch>exit Leaves user mode switch#show version Displays information about software and hardware. switch#show flash: Displays information about flash memory (will work only for the 2900/2950 series). switch#show mac-address-table Displays the current MAC address forwarding table. switch#show running-config Displays the current configuration in DRAM.

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