10 Tips For Up to date 200-105 exam

Answer: D 

Explanation: 

A protocol that establishes, configures, and tests data link connections used by the PPP Link Control Protocol offers PPP encapsulation different options, including the following: Authentication - options includes PAP and CHAP Compression - Data compression increases the throughput on a network link, by reducing the amount of data that must be transmitted. Error Detection -Quality and Magic numbers are used by PPP to ensure a reliable, loop-free data link. Multilink - Supported in IOS 11.1 and later, multilink is supported on PPP links between Cisco routers. This splits the load for PPP over two or more parallel circuits and is called a bundle. 

Answer: D 

Explanation: 

All the above networks can be summarized to 10.0.0.0 network but the question requires to “represent the LANs in Phoenix but no additional subnets” so we must summarized to 

10.4.0.0 network. The Phoenix router has 4 subnets so we need to “move left” 2 bits of “/24-> /22 is the best choice - D is correct. 

Answer: D 

Explanation: 

Frame-relay map ip 192.168.1.2 202 command statically defines a mapping between a network layer address and a DLCI. The broadcast option allows multicast and broadcast packets to flow across the link. The command frame-relay map ip 192.168.1.2 202 broadcast means to mapping the distal IP 192.168.1.2 202 to the local DLCI . When the “broadcast” keyword is included, it turns Frame Relay network as a broadcast network, which can forward broadcasts. http://www.cisco.com/en/US/docs/ios/wan/command/reference/wan_f2.html#wp1012264 

Answer: B,C 

Explanation: A loopback interface never comes down even if the link is broken so it provides stability for the OSPF process (for example we use that loopback interface as the router-id) - B is correct. 

The router-ID is chosen in the order below: 

The highest IP address assigned to a loopback (logical) interface. If a loopback interface is not defined, the highest IP address of all active router’s physical interfaces will be chosen. 

-The loopback interface will be chosen as the router ID of RouterB - C is correct. 

Answer: A 

Explanation: 

PPP permits multiple network layer protocols to operate on the same communication link. For every network layer protocol used, a separate Network Control Protocol (NCP) is provided in order to encapsulate and negotiate options for the multiple network layer protocols. It negotiates network-layer information, e.g. network address or compression options, after the connection has been established 

Answer: D 

Explanation: 

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a008009482f.s html When a switch receives a BPDU, it first compares priority, the lower number wins. If a tie, compare MAC, the smaller one wins. Here Switch has 32769 priority which is greater than 20481 so switch will not elect for root bridge. It says the bridge priority for Switch is 32769, and the root priority is 20481. Which means that some other switch has the lower priority and won the election for VLAN 1. 

Answer: A,D 

Explanation: 

From the output of the “show ip ospf database”: r120#show ip ospf data 

OSPF Router with ID (10.0.0.120) (Process ID 1) 

Next, who are the other routers in our area? Router Link States (Area 1) Link ID.ADV Router.Age.Seq#.Checksum Link count 

10.0.0.111.10.0.0.111.600.0x8000023A 0x0092B3 1 

10.0.0.112.10.0.0.112.1246.0x80000234 0x009CAC 1 

10.0.0.113.10.0.0.113.148.0x8000022C 0x004399 3 

10.0.0.120.10.0.0.120.152.0x80000240 0x0046CB 1 This tells us there are four routers in Area 1. The router with RID 10.0.0.113 has 3 links in Area 1, every one else has only 1 link. Also the router will chose the highest loopback interface as its OSPF router ID (if available). 

Answer: A 

Explanation: 

Spanning Tree Protocol convergence (Layer 2 convergence) happens when bridges and switches have transitioned to either the forwarding or blocking state. When layer 2 is converged, root bridge is elected and all port roles (Root, Designated and Non-Designated) in all switches are selected. 

Answer: C 

Explanation: 

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f07.shtml 

Feasible Successors A destination entry is moved from the topology table to the routing table when there is a feasible successor. All minimum cost paths to the destination form a set. From this set, the neighbors that have an advertised metric less than the current routing table metric are considered feasible successors. Feasible successors are viewed by a router as neighbors that are downstream with respect to the destination. These neighbors and the associated metrics are placed in the forwarding table. When a neighbor changes the metric it has been advertising or a topology change occurs in the network, the set of feasible successors may have to be re-evaluated. However, this is not categorized as a route recomputation. Feasible successor is a route whose Advertised Distance (AD) is less than the Feasible Distance (FD) of the current best path. A feasible successor is a backup route, which is not stored in the routing table but, stored in the topology table. 

Answer: D 

Explanation: 

http://www.ciscopress.com/articles/article.asp?p=170741&seqNum=4 

Frame-Relay (a Layer 2 protocol) uses Inverse-Arp to map a know Layer 2 Address (DLCI) to a unknow Layer 3 Address. Dynamic Mapping Dynamic address mapping relies on the Frame Relay Inverse Address Resolution Protocol (Inverse ARP), defined by RFC 1293, to resolve a next hop network protocol address to a local DLCI value. The Frame Relay router sends out Inverse ARP requests on its Frame Relay PVC to discover the protocol address of the remote device connected to the Frame Relay network. The responses to the Inverse ARP requests are used to populate an address-to-DLCI mapping table on the Frame Relay router or access server. The router builds and maintains this address-to-DLCI mapping table, which contains all resolved Inverse ARP requests, including both dynamic and static mapping entries. When data needs to be transmitted to a remote destination address, the router performs a lookup on its routing table to determine whether a route to that destination address exists and the next hop address or directly connected interface to use in order to reach that destination. Subsequently, the router consults its address-to-DLCI mapping table for the local DLCI that corresponds to the next hop address. Finally, the router places the frames targeted to the remote destination on its identified outgoing local DLCI. On Cisco routers, dynamic Inverse ARP is enabled by default for all network layer protocols enabled on the physical interface. Packets are not sent out for network layer protocols that are not enabled on the physical interface. For example, no dynamic Inverse ARP resolution is performed for IPX if ipx routing is not enabled globally and there is no active IPX address assigned to the interface. Because dynamic Inverse ARP is enabled by default, no additional Cisco IOS command is required to enable it on an interface. Example 4-16 shows the output of the show frame-relay map privileged EXEC mode command. The addressto-DLCI mapping table displays useful information. The output of the command shows that the next hop address 172.16.1.2 is dynamically mapped to the local DLCI 102, broadcast is enabled on the interface, and the interface's status is currently active. 

NOTE After enabling Frame Relay on the interface, the Cisco router does not perform Inverse ARP until IP routing is enabled on the router. By default, IP routing is enabled on a Cisco router. If IP routing has been turned off, enable IP routing with the ip routing command in the global configuration mode. After IP routing is enabled, the router performs Inverse ARP and begins populating the address-to-DLCI mapping table with resolved entries.