network availability Flashcards
availability vs reliability
availability : network being up and operational
reliability: network not dropping packets
MTTR
Mean time to repair: measures average time to repair a network device when it breaks
MTBF
`Mean time between failures
the higher the better the availability and reliability
NIC teaming
using several NICs for load balancing and failover on a server
SPD
Selective Packet Discards: router drops low priority packets to prioritise high QoS traffic
What is a Runt?
a runt is a packet that is too small.
the Ethernet protocol requires that each packet be at least 64 bytes long.
In Ethernet, which operates CSMA/CD, runts are usually the fragments of packet collisions.
Runts can also be the result of bad wiring or electrical interference.
What is a Throttle?
Throttle occurs when the interface fails to buffer the incoming packets
What is a CRC?
of packets that failed the cyclic redundancy checksum (CRC) check upon receipt
overrun
how often the interface was unable to receive traffic due to an insufficient hardware buffer
underrun
times the sender operated faster than router can handle, causing buffers or dropped packets
Giants vs Babbles
Giant: frame +1518 bytes (received)
Babble: frame +1518 bytes (transmitted)
Deferred
frames transmitted after waiting because the media was busy
! Full duplex vs half-duplex
Which server configuration involves combining multiple NICs that simultaneously work together providing redundancy, and higher overall throughput?
NIC teaming is a technology used to logically combine Network Interface Cards (NICs) to make them appear as one or more logical interfaces. This technology provides fast performance and fault tolerance.
First Hop Redundancy Protocols
VRRP (multiple standby)
HSRP (only one standby)
Load balancing protocol
GLBP (gateway load balancing protocol) - active-active configuration, load balancing between two routers (active & standby)
LACP (link agrgregation control prot) - L2 (switches) 802.1ad
