Server Operating Systems and Server Roles Flashcards
server roles (planning)
- determine if multiple roles will be located on the same server or dispersed across multiple servers
- cloud VMs can offer services to other cloud devices/internet consumers/on-premise devices
configuring on-premise connections with VMs
- site-to-site VPN connections
- dedicated connections from on-premise networks to cloud provider networks (bypass internet)
DHCP
- dynamic host configuration protocol
- delivers central IP settings to network nodes
- can run on a server OS or as a service on a router
DCHP port numbers
- UDP 67 (listens for client requests)
- UDP 68 (sends responses to client requests)
DHCP scopes
- IP settings grouped into a manageable unit
- must be activated before they can be used in DHCP process
- IP address ranges
- IP address exclusions
- IP address lease duration
- default gateway
- DNS servers
- DHCP reservation
DHCP vendor classes
- apply specific IP settings to certain types of network devices
- must determine what vendor class data is included in network transmission
APIPA
- automatic private IP addressing
- clients use to assign itself a unique address on the LAN when can’t reach DHCP server
- client not able to communicate outside the LAN
- can only communicate with other APIPA hosts within the LAN
link-local address
- used in IPv6
- unique self-assigned address
- always bound to network interface whether or not DHCP is reachable
considerations for choosing DHCP configuration
- determine which valid IP address ranges can be used
- short lease duration in environments where clients connect for short periods of time
- try to specify at least 2 default gateways for redundancy
- try to specify at least 2 DNS servers for redundancy
- configure DHCP bindings for correct network interface in multihomed (multiple network card) DHCP servers
- high availability
DNS
- find IP address for FQDN (forward lookup)
- find FQDN for IP address (reverse lookup)
DNS port number
listens on port 53 (UDP/TCP)
DNS domains
- root domain at top
- TLDs (.com/.org/.net/etc)
- domains can have subdomains
- subdomains may have their own authoritative DNS servers
SOA (DNS RR)
- start of authority
- contains zone details i.e. serial number/refresh interval
- can exist in forward and reverse lookup zones
A (DNS RR)
- forward lookup record
- FQDN included in query
- IPv4 address returned
AAAA (DNS RR)
- forward lookup record
- FQDN included in query
- IPv6 address returned
CNAME (DNS RR)
- canonical name record/alias record
- additional name for an existing name
- can be used in forward/reverse lookup zones
- return FQDN that can be resolved via an A record
MX (DNS RR)
- mail exchanger
- used for email domain suffixes to locate an SMTP mail server
- return FQDN that can be resolved via an A record
SRV (DNS RR)
- service record
- used to locate a network service i.e. AD
- includes TCP/UDP port numbers for service
- clients query DNS SRV records to locate services
PTR (DNS RR)
- pointer record (reverse DNS record)
- created in reverse lookup zone
- client queries include IP address
- host/DNS domain name returned
- each PTR record should have an associated A record
WINS
- Windows Internet Name Service
- used in Microsoft TCP/IP networks prior to Windows 2000 to resolve NetBIOS computer names to IP addresses
- replicated database of NetBIOS computer names and their IP addresses
- no naming hierarchy
- installed as a feature on Windows server 2019 for backward compatibility
DNS GlobalNames zone
- client devices can point to a DNS server where a zone “GlobalNames” exists
- alternative to WINS
- DNS admins create CNAME records that point to A records
- enables older software using flat computer names to function through DNS
NTP
service running on network host to provide time synchronization
NTP port number
listens on UDP 123
stratum 0 (NTP)
time source/reference clock
stratum 1 (NTP)
NTP server connected to stratum 0 device
stratum 2 (NTP)
NTP server gets time over network from stratum 1 host
directory services (DS)
- centralized network database containing objects (users/groups/computers/network service locators/shared folders/shared printers/software licenses)
- Microsoft AD DS
- OpenLDAP
- Oracle Directory Services
- IBM Tivoli Directory Server
- based on the same LDAP standards
LDAP port numbers
- listens on TCP 389 (plaintext)
- listens on TCP 636 (encrypted)
AD
- Microsoft active directory
- LDAP compliant
- replicated network database
- synchronized between DCs
- group policy
- Windows server role
- installed via Server Manager or PowerShell cmdlets
DC
- domain controller
- server configured to hold a replica of the AD database
- C:\Windows\Ntds\Ntds.dit
- discovered by clients via DNS queries
- creation of DC creates DNS service location records
web server
- use HTTP/HTTPS to present content to web browser
- Microsoft Internet Information Services (IIS)
- Apache
- NGINX
web server ports
- TCP 80 (HTTP)
- TCP 443 (HTTPS)
application server
- serves data with a specific business purpose
- often combination of web/database servers
- Microsoft SQL Server
- MySQL
- Oracle Database
file server
- data stored on equipment owned/managed by the organization (legal reasons)
- Windows servers use SMB to make shared folders available over the network
- UNIX/Linux systems use their own network file system (NFS) but can use SMB via Samba
print server
- manages printers on a network
- spool print jobs from clients using server disk space
cloud printing
- remove any printing dependencies i.e. OS versions/print drivers/printing devices/etc
- can be used with mobile devices
mail server
- run as services (daemons)
- enable connections on specific ports
- need to support mobile device connections
MDM tools
- mobile device management
- mobile device partitioning solutions for personal/work data
- restrict file attachments from corporate messages from being stored on personal cloud storage locations
- can run on-premise or in cloud
SMTP
- simple mail transfer protocol
- port 25
- used to transfer email between SMTP hosts
POP
- post-office protocol
- port 110
- enables clients to download email messages from POP server