ROUTING Flashcards
Distance vector
- focus on # of hop counts
sends full copy of routing tables to direct neighbours at regular intervals - slow convergence
ex. RIP
Link State
- focus on cost and speed
- faster convergence
- requires all the Routers to know about the paths that all other routers can reach in the Network
OSPF, IS-IS
hybrid
mix of DV & LS
focus on bandwidth & delay
EIGRP –> CISCO only
Exterior
BACKBONE OF THE INTERNET
BGP: slow convergence
path vector that uses the # of autonomous systems hops (vs router hops)
PROT | TYPE | INT/EXT | AD
direct connected 0
static connection 1
EIGRP HYBRID INT 90
OSPF LS INT 110
RIP DV INT 120
BGP PV EXT
unknown/ unbelievable 255
MPLS
Multiprotocol Label switching: routes packets through WAN using labels (common WAN technology)
ISP Edge router adds labels packets and the other end ISP edge router removes the labels before passing onto customer edge router
Demarcation point (demarcation)
point where you connect with the outside word -WAN/ ISP edge router
controlled by smart jack (Network Interface Unit) : build in diagnostics and loopback tests
What is considered a classless routing protocol?
OSPF is known as a classless protocol. Classless routing protocols are those protocols that include the subnet mask information when the routing tables or updates are exchanged. Other classless routing protocols include EIGRP, RIPv2 (or newer), and IS-IS.
An organization has hired you to upgrade its wired computer network. The network currently uses static routing for the internal network, but the organization wants to reconfigure it to use a dynamic routing protocol. The new dynamic routing protocol must support both IPv4 and VLSM. Based on the requirements provided, which of the following routing protocols should you enable and configure?
Only OSPF supports IPv4 and VLSM (Variable Length Subnet Mask) from the options provided in this question. Open Shortest Path First (OSPF) is a link-state routing protocol that was developed for IP networks and is based on the Shortest Path First (SPF) algorithm.
FHRP
First Hop Redundancy Protocols: group of protocols to support high availability and redundancy
- VRRP (VIRTUAL router redundancy protocol) open standard, based on virtual gateway
- HSRP (Hot Standby Router protocol) : Cisco-proprietary
Both HSRP and VRRP enable two or more devices to work together in a group, sharing a single IP address, the virtual IP address. The virtual IP address is configured in each end user’s workstation as a default gateway address and is cached in the host’s Address Resolution Protocol (ARP) cache.
Your company wants to create highly available datacenters. Which of the following will allow the company to continue maintaining an Internet presence at all sites if the WAN connection at their own site goes down?
If a WAN link goes down, BGP will route data through another WAN link if redundant WAN links are available. Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information between autonomous systems (AS) on the Internet. The protocol is often classified as a path vector protocol but is sometimes also classed as a distance-vector routing protocol.
Which of the following IP routing protocols is classified as link-state?
OSPF (Open Shortest Path First) is a link state routing protocol. RIP is a distance Vector routing protocol. EIGRP is an advanced Distance Vector routing protocol. BGP is considered a path vector routing protocol.
What routing protocol bases its metric off of Bandwidth and cumulative Delay?
EIGRP is an Advanced Distance Vector routing protocol that uses the metric, Distance, which is based on a calculation of Bandwidth and Delay. RIP (Routing Information Protocol) and RIPv2 use hop count to calculate their metric. OSPF (Open Shortest Path First) uses cost to calculate its metric. Cost is based on the bandwidth of a link.
Which table holds temporary IP address to MAC address mapping?
The ARP (Address Resolution Protocol) table is used to store temporary MAC address to IP address mappings, which is vital for the IPv4 routing process. ARP is a Data Link protocol used to dynamically map an IP address to a MAC address.
What type of static route is used when there isn’t a specific entry in the routing table for the destination network?
With a default route, an address of 0.0.0.0 and subnet mask of 0.0.0.0 is used to prevent this from happening.
A floating static route is a static route that is meant as a backup to the main route, with the main difference being the metric of this route is set higher.
