HCDA HC-211 HC-211 Exam: 1) What is the SMTP port number? 25 Hint: 20/21 FTP, 23 Telnet, 22 SSH, 80 HTTP, 25 SMTP 2) What is the shortcut command to browse thru historical commands? a) Ctrl – P – previous history command in buffer b) Ctrl – N – next history command in buffer c)
Ctrl – U – display ip int brief
d) Ctrl – L – display ip routing-table e) Ctrl – G – display current configuration f)
Ctrl – O – undo debugging all
3) IP Address contains two components: network address and host address and it is a 32bit dotted decimal value. 4) UDP does not provide reliability for delivery, instead it depends o n application layer protocol to ensure reliability of the delivery (RTP) 5) What are the routed protocols? a) IP b) IPX c)
Appletalk
6) What are the routing protocols? a) RIP b) OSPF c)
IS-IS
d) BGP 7) What is the EGP protocol? BGP 8) What are the IGP protocols? -
RIP, OSPF, IS-IS
9) What is the full name for VLAN? -
Virtual Local Area Network
10) What is the full name for STP? -
Spanning Tree Protocol
There are three types of BPDUs:
Configuration BPDU (CBPDU), used for Spanning Tree computation Topology Change Notification (TCN) BPDU, used to announce changes in the network topology Topology Change Notification Acknowledgment (TCA)
11) What is the message sent between switches for the STP convergence?
-
Configuration BPDU
12) What is the switch priority default value? -
32768
13) V.35 synchronous mode the maximum transmission rate is 2048kpbs or
2Mbps 14) 802.1q Vlan tag located at the END of both source and destination mac address in the Ethernet frame. 15) Ethernet frame type 0800 represents an Ethernet_II frame and IP datagram header. 16) Console settings on communication ports (COM port) for Quidway devices as: -
9600 bits per second, 8 data bits, 1 stop bits, Parity and Flow control NONE
17) Which of the following protocols are operating at Transport layer? -
TCP, UDP
18) Ethernet switches operate at _____? -
Data Link layer
19) What is the vendor id for Huawei device address? -
00e0fc
20) Mac address (aka hardware address) is a 48 bit of hexadecimal value 21) Applications as RADIUS and SNMP that use the transport efficiency to deliver data using….?
-
UDP
22) What are true about PSTN circuit switching network? -
High capacity communication link
-
Ensure QoS
23) What is the statement true about NAT? -
NAT – Network Address Translation
-
Required to translate private address to public address when accessing outside resources like Internet
-
Can be used to substitute the depletion of public ip addresses
-
It helps to hide private address from o utside (preserving ip address privacy)
24) Which statements are true about VLAN in VRP? 25) What statement is true about VRRP? 26) MAC address is 48-bit hexadecimal value 27) Router and layer 3 switch operate at Network layer 28) Network layer protocols includes: -
IP/ICMP/ARP/RARP
-
Routing protocols : OSPF, IS-IS, RIP, BGP
-
Routed protocols: TCP/IP, IPX/SPX, AppleTalk
29) Comparison between TCP and UDP: -
TCP (Transport Control Protocol)
o
-
Reliable
o
Connection-oriented
o
Support bulk delivery
o
Retransmission capable
o
High overhead/cost
UDP (User Datagram Protocol) o
Non-reliable
o
Connectionless
o
Used in small chunks of data delivery (voice and video streams) – transport efficiency
o
No retransmission
o
Low overhead/cost
30) Presentation layer covers data encryption and formatting as ASCII, JPEG, MPEG, GIF, DES, 3DES, AES, SHA1, MD5, etc 31) Application layer covers user and network applications as HTTP, HTTPs, SMTP, FTP, TFTP, Telnet, SSH, DNS, SNMP, RADIUS, etc Note: TCP applications include TELNET, SSH, FTP, HTTP, SMTP, POP3, DNS UDP applications include RADIUS, RIP, SNMP, DNS, TFTP, RTP 32) Types of network topologies available include: -
Bus
-
Ring
-
Star
-
Grid or Mesh
33) ICMP operates at Network layer; its applications include ping, tracert/traceroute 34) IPv6 Addressing -
128-bit colon-separated hexadecimal values
-
Prebuilt-security – IPSec
-
Auto-configuration, DHCP, link-local addressing
-
Rules governing valid IPv6 addresses o
There is ONLY one double colon (::) per address
o
Two to multiple sets of contiguous zeros c an be represented with a double colon
o
-
Leading zeroes can be omitted
Examples of valid IPv6 address: o
Fe20:0000:0000:0000:009b:820c:0001:000b
o
Fe20::9b:820c:1:b
o
2001:0000:0000:0bde:100b:0000:0000:009b
o
2001::bde:100b:0:0:9b
o
2001:0:0:bde:100b::9b
35) Classes of IP Address -
32-bit dotted decimal value
-
3 usable business ip addresses (Class A, B and C)
-
Class D is reserved for multicast addressing
-
Class E is reserved for scientific research (abundant and not in use)
a) Class A -
X1.x2.x3.x4 (where x1 = 1 -126)
-
Default subnet mask 255.0.0.0 or /8
-
Example: 10.0.0.0/8
b) Class B -
X1.x2.x3.x4 (where x1 = 128 – 191)
-
Default subnet mask 255.255.0.0 or /16
-
Example: 172.16.0.0/16
c)
Class C
-
X1.x2.x3.x4 (where x1 = 192 -223)
-
Default subnet mask 255.255.255.0 or /24
-
Example: 192.168.1.0/24
d) Class D -
X1.x2.x3.x4 (where x1 = 224 – 239)
-
No default subnet mask
-
Example: 224.0.0.1
e) Class E f)
X1.x2.x3.x4 (where x1 = 240 -255)
-
No default subnet mask
Subnet calculation Formulas: 1. 2^h – 2 = Total available host addresses (number of ip addresses that can be used) 2. N + h = 32 (N – network bits, h – host bits) 3. 2^h = Network size or network range 4. 2^m = Total number of subnetworks (where m – subnetwork bits) m is derived from the network bit borrowed from host bit 36) To show the routing paths on the VRP platform router, what command to be used: -
Display ip routing-table
-
Display ip routing-table protocol static | rip | ospf | bgp o
It shows the respective routes from the specific routing mechanism
37) Routers learn the destination paths through the following methods: a. Discovered by routing protocols through router peers/neighbors (Network layer) – dynamic routing for remote networks
b. Discovered by Data Link layer (local interface or network) – local networks c.
Manually managed by the network administrator – static routing for remote networks
38) Routing protocols classified by routing algorithm as follows: a. Distance Vector
o
Routing mechanism used by RIP (RIPv1/RIPv2) to learn r outes through neighbor route exchange; routing by rumours (depends on neighbor updates)
o
Algorithm used is Bellman Ford
b. Link State -
Topology-based routing used by OSPF and IS-IS; routes are updated and calculated individually by the routers through neighbor interface state update
c.
Algorithm used is Dijsktra Shortest Path First (SPF)
Path Vector -
Hop count based routing used by BGP routing; one hop is one autonomous system (AS)
-
Routing update is manually administered by network administrators through selective route manipulation.
-
Source-based routing (route filtering mechanism used)
39) Routing priority by a router is defined in this se quence order: st
a. 1 priority – longest match on the prefixes nd
b. 2 priority – routing preference (it varies among different routing processes) For example Router A found the network 172.16.10.0/24 through 2 approaches; one learnt from RIP protocol and another through the OSPF protocol. Hence, the router will take the route learnt from OSPF because OSPF has a high priority since its preference value is 10 compared to RIP which is 100 (Hint: Lower prefere nce value means higher priority) For instance, Router A found these networks as 172.16.0.0/16 with RIP and 172.16.10.0/24 through static routing in its routing table but the packet needs to be routed to the destination host at 172.16.10.109. The router will take the path based on the longest prefix match which is the route 172.16.10.0/24 (longer prefix of 24 bits) 40) Which type of routing requires manual administration when the network topology change and the change is not automatically updated without human intervention? -
Static routing
41) Which statements are true about dynamic routing? -
Both end routers need the same routing protocol in order to communicate
-
Both end routers need to propagate its own networks to exchange the routing information
-
Routing protocols will take the network topology change automatically
42) Routing protocol used to exchange routes betwee n two different administrative boundaries as autonomous systems (AS) will be known as ? -
Border Gateway Protocol (EGP)
43) What are the correct types of multicast routing protocols?
-
DVMRP, PIM-DM, PIM-SM
44) What are the correct types of unicast routing protocols? -
OSPF, RIP, BGP, IS-IS
45) A routing table consists of the following components as? -
Destination/path, protocol, metric/cost, next-hop, interface (outbound) and preference Note: Routing mechanism
PREFERENCE
---------------------------
------------------
OSPF
10
IS-IS
15
RIP
100
OSPF ASE
150
iBGP
255
EBGP
255
Direct/local
0
Static routing
60
46) Best paths are derived from the value of cost/metric or number of hops depe nding on the routing protocol types. Different routing protocols use different metric for the paths. -
Example, RIP uses the number of hops to define the best paths. RIP will cho ose the least number of hops to reach the destination network
-
OSPF and IS-IS believe in cost. Cost is derived from the calculation of the total path cost along the journey to the destination networks.
47) Scenarios that benefit to different routing mechanism and processes as follows: a) Network topologies are subject to change due to organization structural change
and the size of the network is small and simple. Solution: RIP (RIPv2) b) Network topologies are not subject to regular change or maintenance and the network size are ranging from small to medium with permanent addressing. Solution: Static routing c) Networks are subject to change and regular maintenance required due to business merging and acquisition. Network topologies and size range from small to large enterprise level. Solution: OSPF or IS-IS d) Network topologies and size capacity covers multi-countries and locations; administrative maintenance is classified into different security boundary ranging from one autonomous system to another. Common deployment includes service providers of different levels: national, regional and international. Solution: BGP 48) Classes of Routing protocols -
Classful routing o
-
Supports only FLSM (fixed length subnet mask)
Classless routing o
Supports both FLSM and VLSM (variable length subnet mask)
o
Supports CIDR (classless interdomain routing) – summarized routing
-
Examples:
-
Classful routing protocol is RIPv1
-
Classless routing protocols are OSPF, RIPv2, IS-IS, BGP
49) Load balancing and backup routes for Static Routing Ip ro ute-static [destination] [mask] [gateway1] Ip route-static [destination] [mask] [gateway2] -
Both are valid routes with load balancing capacity Ip route-static [destination] [mask] [gateway1] preference x Ip route-static [destination] [mask] [gateway2] preference y If x>y then gateway2 will be the primary route pathfinder
50) What makes RIPv2 is gaining competitive advantage over RI Pv1? a. Multicast communication among the peers (224.0.0.9) b. Peer authentication using plaintext or MD5-encrypted password c.
Classless routing protocol supporting CIDR and VLSM
d. Flexibility to support manual and automatic route aggregation (RIPv1 only supports automatic route aggregation) 51) OSPF works at Network layer and the protocol ID value in the IP header field is 89 52) What are the correct statements about OSPF routing protocol? -
Runs on network layer with IP protocol ID 89
-
Link State routing protocol which is a fast convergence and triggered update support
-
Uses multicast to communicate with peers (224.0.0.5 and 224.0.0.6)
-
Supports CIDR and VLSM addressing
-
Scalable routing with area design
-
Support equal cost multipath (ECMP) routing (load balancing and redundant paths)
-
Support MD5 and clear text password for peer authentication
-
Uses bandwidth to calculate the best path (lowest cost path)
-
No automatic route aggregation support (only support manual route aggregation)
-
Uses Dijkstra Shortest Path First (SPF) routing algorithm
-
Contains 3 sets of databases: adjacency/neighborship, LSDB and routing tables
53) OSPF routers maintain their network topology in a single shared copy of the database known as Link state Database (LSDB). All routers in the same area share the same copy of the LSDB. LSDB is unique per OSPF routing are a. 54) Virtual Router Redundancy Protocol (VRRP) – used to provide Layer 3 gateway redundancy -
Master router is selected based on priority value (higher priority is preferable)
-
Multiple virtual routers can be configured on the same interface
-
Virtual router id ranges from 1 -255
-
Virtual router ID configured on all the VRRP routers of the same virtual group must be the same
-
Virtual router can be associated w ith more than one virtual ip addresses
-
Virtual ip address configured for the VRRP router of the same virtual router should be the same
-
The priority value 255 means the owner of the VRRP master (the VRRP router physical ip address is set to be the same as Virtual router ip address)
-
Priority value 0 means the VRRP router is going to release the role off
-
The priority value for VRRP range from 0 -255 with the exception that 0 and 255 are reserved exclusively for the VRRP down state while the later is meant that the ip address and virtual ip address of t he VRRP router set to the same.
55) With PPP encapsulation on the synchronous links, LCP detects the status of the link by using the Echo-request and Echo-reply packets. Echo-request packet is sent every 10 seconds .
56) Frame Relay operates at Data Link layer adopting virtual circuit technology; providing high throughput and low delay, QoS capable transmission of shared network. 57) Local Management Interface (LMI) monitors the status of P VC; 3 kinds of LMI standards are supported: Q.933 Annex A (ITU-T), T1.617 Annex D (ANSI) and Cisco (non-standard ) 58) Frame Relay address mapping associates local protocol address with the local DLCI statically with the command fr map ip [ip_address] [local_dlci] or via dynamic learning with frame relay inverse ARP (command fr inarp) 59) Verifying the mapping table containing remote ip address with local DLCI using the command display fr map-info 60) Strict control policy restricts all network traffics unless otherwise selectively permitted while Loose Control policy permits all network traffics unless otherwise explicitly denied. 61) Packet Filtering firewall utilizes special rules obtaining from source and destination ip addresses, source and destination ports and protocol number of the data packets to filter data packet passing through the firewall. 62) Stateful packet inspection firewall detects protocol information of the application layer and monitor the protocol state of connection-oriented applications. 63) Firewall Security Zone 64) GVRP no t enable, if non local VLAN received, what switch will do ? 65) VRRP stand for 66) ICMP using port number ? 67) VRRP stands for 68) Virtual Ip can have multiple or 1 for each virtual router ? 69) Proxy firewall select 3 70) DHCP application or network layer protocol 71) Activate PAP command
72) Enable HDLC command 73) HDLC standard from ISO for asycn or sync 74) Router interface is MDI or MDI-X 75) Default STP priority 76) Function of inverse ARP 77) Steps on create interface vlan and vlan 78) Circuit switching – low delay is not the answer 79) RIP Timer to delete route 80) Switching method –s tore and forward can detect less than 64, fragment free is < 64 81) MTU size range 46-1500 82) MRU default is 1500 83) Max Default route -2 routes ? 84) 3 method- > console, telnet and AUX 85) Status of backup route – inactive 86) Port based mirroring – redirect 87) DCE – Modem. CSU and DSU and Switch 88) STP –redundancy for physical path and not logical 89) Circuit switching – low delay is not the answer 90) Loop – Loop will cause congestion and TTL will be 0 when drop 91) LMI – 0 and 1023 92) Max number of default route for load balance ??? 16 default
