IP Services Flashcards
What is NTP and how does it work?
Network Time Protocol is a UDP based protocol that synchronizes a set of network clocks in a distributed client/server architecture.
What are stratum 1 servers?
Stratum 1 servers are directly attached to an authoritative time source.
What is HSRP and how does it work?
Hot Standby Router Protocol is a Cisco proprietary protocol that provides transparent failover of the first-hop device, by using a virtual IP address as the gateway.
How does the active/standby election process work?
The router with the highest priority (defaults to 100) is selected as active. In a tie, the router with the highest IP address for the network segment is preferred.
What does it mean that HSRP does not support preemption by default?
This means by default, an active router will not automatically transfer its active status to a router with a higher priority.
What is VRRP and how does it differ from HSRP?
Virtual Router Redundancy Protocol (VRRP) is an industry standard that operates just like HSRP except for the following:
- Instead of active/standby router it is called master/backup router.
- VRRP enables preemption by default.
What is GLBP and what does it do?
Gateway Load Balancing Protocol (GLBP) provides gateway redundancy and load-balancing capability to a network segment.
What is the AVG and what does does it do?
Active virtual gateway (AVG) is the router in the GLBP group that responds to initial ARP requests for the VIP.
What is the AVF and what does it do?
Active virtual forwarder (AVF) is a router that forwards traffic from assigned hosts.
What is NAT and what does it do?
Network Address Translation (NAT) enables the internal IP network to appear as a publicly routed external network.
What is the inside local address?
The inside local address is the actual private IP assigned to a device on the inside network.
What is the outside global address?
The outside global address is the public IP that represents one or more inside local IP addresses to the outside.
What is the outside local address?
The outside local address is the IP of an outside host as it appears to the inside network. The IP address does not have to be reachable by the outside but is considered private and must be reachable by the inside network.
What is the outside global address?
The outside global address is the public IP assigned to a host on the outside network. This IP address must be reachable by the outside network.
How does Static NAT work?
Static NAT works by providing a static one-to-one mapping of a local IP address to a global IP address.
