Review End of Semester

Review First Half of Semester

First Half What is infrastructure Computer Basics Number systems Data storage Numbers Characters

First Half Networks MAC addresses IP TCP/UDP ARP Only way one computer can connect to another Unique addresses for all NICs IP Unique addresses for computers Within a network IPv4 ~4 billion addresses in 5 Classes IPv6 ~3.4x1038 addresses TCP/UDP Ways to transmit data Assured delivery (TCP) Low overhead (UDP) ARP Find the MAC address of a computer Local network

First Half Networks Switches allow connections between computers In a local network Only computers in their (logical) network are allowed to directly communicate Routers Transmit data from one network to another NAT DHCP

First Half DNS Gives "human" names to computer addresses Is not "really" needed Makes the Internet human friendly Arguably the most important service on the Internet

First Half HTTP HTML Allows retrieving of "HyperText" material Language of the HyperText Formatting Referencing other docs

Second Half of Semester

Last Half Web Servers Mail Servers Apache IIS HTTP server NGINX Many others… Mail Servers SMTP POP and IMAP

Last Half Telenet, et. Al. SSH Remote control over network rsh, rlogin Remote file access rcp, ftp Typically unsecure But not entirely obsolete! SSH Secure network protocols ssh, scp, sftp, etc…

Last Half Storage How a disk works RAID LVM Operational parameters 0 – striped Bigger, faster Single failure complete data loss 1 – duplicated Wasted space No loss if drive failure 5,6 – redundancy though parity Can survive one or more drive losses LVM Can manage drives

Last Half Distributed Files Systems NAS/SAN Access other systems data NFS, AFS, SMB NAS/SAN File access (NAS) Multiple access by various users/systems By files Block access (SAN) Only one system may access Like an unformatted hard drive

Last Half SNMP LDAP SPAM Monitor/Control Network resources Client/server Monitors are the clients Network devices are the servers LDAP Directory Protocol SPAM Indirectly impacts Infrastructure

Last Half Network Computing Backup VNC VPN Remote access to a computer Accesses the GUI VPN Extending a secure network to remote locations Accesses the resource Backup Critical to ensure data is kept “safe” Often overlooked or ignored