2.4 - Network Services Flashcards
DNS server
Domain name system
Convert names to IPs and vice versa
Distributed naming system
-load = balanced across different servers
Usually managed by ISP or IT dept
-CRITICAL resource
DHCP server
Dynamic host configuration protocol
Automatic IP config.
Common device
-available on most home routers
Enterprise DHCP = redundant
-usually running on central servers
File server
Centralized storage of docs, spreadsheets, pics, vids, etc
-a fileshare
Standard system of file management
-SMB (server message block)
-AFP (apple filing protocol)
-etc.
Front end hides protocol
-copy
-delete
-rename
-etc.
Print server
Connect printer to network
-provide printing services for all network devices
Might be software in computer
-computer = connected to printer
Might be built in to printer
-network adapter + software
Uses standard printing protocols
-SMB (server message block)
-IPP (internet printing protocol)
-LPD (line printer daemon)
Mail server
Store incoming mail
-send outgoing mail
Typically managed by ISP or IT dept
-complex requirements
One of the most IMPORTANT services
-24/7 support
Syslog
Standard for message logging
-diverse systems
-consolidated log
Typically central logging receiver
-integrated into SIEM
Needs a lot of disk space!
Web server
Responds to browser requests
-uses standard web browsing protocols (HTTP/HTTPS)
-pages = built with HTML, HTML5
Web pages = stored on server
-downloaded to browser
-static pages or built dynamically in realtime
Authentication server
Login authentication to resources
-centralized management
Almost always an enterprise service
-not required on home network
Usually a set of redundant servers
-always available
-extremely IMPORTANT service
Spam
Unsolicited messages
-email
-forums
-etc.
Different content
-commercial advertising
-phishing attempts
-non commercial proselytizing
Significant tech issue
-security concerns
-resource utilization
-storage costs
-managing the spam
Spam gateways
Unsolicited email
-stop it at gateway before it reaches user
-on site OR cloud based
All in one security appliance
Next gen firewall, Unified threat management (UTM)/Web security gateway
URL filter/content inspection
Malware inspection
Spam filter
CSU/DSU
Router, switch
Firewall
IDS/IPS
Bandwidth shaper
VPN endpoint
Load balancers
Distribute load
-multiple servers
-invisible to end user
Large scale implementations
-web server farms
-database farms
Fault tolerance
-server outages have no effect, fast convergence
Load balancer features
Configurable load
-manage across servers
TCP offload
-protocol overhead
SSL offload
-encryption/decryption
Caching
-fast response
Prioritization
-QOS
Content switching
-application centric balancing
Proxy server
Intermediate server
-client makes request to proxy
-proxy performs actual request
-proxy provides results back to client
Useful features
-access control
-caching
-URL filtering
-content scanning
SCADA/ICS
Supervisory control and data acquisition system
-large scale, multi site ICS (industrial control systems)
PC manages equipment
-power generation, refining, manufacturing equipment
-facilities, industrial, energy, logistics
Distributed control systems
-real time info
-system control
-requires extensive segmentation
-no access from outside
