100-101 ICND1 Review

What is the range for Class A IP?

1 - 127

What is a Class A Private IP Addressing?

10.0.0.0 through 10.255.255.255

When you hardcode a interface to 100Mb on full duplex and other is on auto negotiation, what will it have for speed and duplex?

100 half. On auto, it can only detect by standards only that if the other is on auto as well. If not, it will not know what to do therefore it will go on auto only. It only changes when it is on 1000 Mb

What is the IP range for Loopback Addressing?

127.0.0.0 through 127.255.255.255

What is the range for Class B IP?

128 - 191

What is the IP range for Automatic IP addressing?

169.254.0.0 through 169.254.255.255

What is a Class B Private IP Addressing?

172.16.0.0 through 172.31.255.255

What is the range for Class C IP?

192 - 223

What is a Class C Private IP Addressing?

192.168.0.0 through 192.168.255.255

What is default destination port on TCP for SSH, TELNET, SMTP, HTTP, HTTPS, IMAP and POP 3

22, 23, 25, 80, 443 143 and 110

What is the range for Class D IP and what is it designed for? Why can't they use Unicast or Broadcast?

224 - 239. Designed for multicast addresses. Typically used for servers designed to broadcast a IP addresses used for re imaging or another assortment of other functions.

What is the range for Class E IP and what is it designed for?

240-254. Designed for experimentation only. Not used for public but used for engineers typically designing new functions.

What is the Max Recommended hosts per network before broadcast start to slow down the network for IPv4?

500

What is default destination port on UDP for DNS and TFTP?

53 and 69

What is the difference between a HUB, a Bridge and a Switch?

A Hub is a "Dummy" switch that is a half duplex device. It broadcasts all to the computers on the network, collision domain is incurred. A Bridge is a software ran device that learns MAC addresses between HUBs. A Switch is a condensed, Collision domain-per-port MAC address learning device. It utilizes ASIC to switch from software to hardware to learn MAC addresses to main speed.

What feature is used to detect which media to connect from switch to switch? What does it do?

Auto MDIX. Able to detect if you have a straight through or a cross-over cable. Made 5-6 years ago.

What is the CAM table, what does it do? How long does it last?

CAM table is essentially the intelligence of a L2 network, it learns the MAC addresses to allow a PTP network. It is not stored when the system shuts down. It takes between 5-10 seconds for it to re-learn the networkIt lasts up to 5 minutes but it can be changed.

Where does Syslog show? What does it show?

Console, Shows Time and Date. Shows which port its logging from and which ip its coming from.

What Protocols are used in the transport layer?

TCP, UDP, EIGRP, OSPF, ICMP

For Cisco [Not part of Exam but need to know] what do other vendors call "Trunk"

Tagged. When it needs to leave its route and goes with the other frames, it gets "tagged" to remind where it needs to go.

What is the process to do a Subnet for a Class A Network for a 10.0.0.0 under a /8 subnet mask for 1500 networks?

Determine number of networks and convert to binary (11 bits total, start at (2048 + 1024 + 512 + 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1). Reserve Bits in subnet mask and find your increment. then apply all bits and place in subnet mask. 255.255.224.0. Use increment to find your network ranges, which in this case starts at the 3rd bit which is "32". You take that too and you place it in the IP range which is 10.0".0.0" - 10.0".31.255" and next is 10.0".32.0" to 10.0."63.255" and all the way to 10.255.255.255.

What is the process to do a Subnet for a Class B Network for a 149.6.0.0 under a /16 subnet mask for 120 networks?

Determine number of networks and convert to binary (7 bits total, start at 64 + 32 + 16 + 8 = 120). Reserve Bits in subnet mask and find your increment. then apply all bits and place in subnet mask. 255.255.254.0. Use increment to find your network ranges, which in this case starts at the 7th bit which is "2". You take that too and you place it in the IP range which is 149.6."0.0" - 149.6."1.255." Next is 149.6."2.0" - 149.6."3.255" and so on.

What is the process to do proper subnetting for a Class C? If its a 50 network requirement under a class C, what would be the benefit to it?

Determine number of networks and convert to binary (example if its 6 then it will be 3 bits from the right = 7). Reserve Bits in subnet mask and find your increment (reserve the bits from the host, 3 bits = 224. Use increment to find your network ranges (last bit = 32, each increment is of 32). For Routing Network IP's as the best. Other is for Management VLANs.

What is DHCP? What does it do?

Dynamic Host Configuration Protocol. Functions is to less the burden for administrators and to distribute IP leases to each host.

When sending information inside a Packet, what is encapsulated in it in what order?

FRC/CRC > SYN > SRC PORT > SRC IP > DEST IP > SRC MAC > DEST MAC

What is benefits of VLANs

Isolation and reduce congestion

What is UDP? What is it typically used for? Is it fast or slow?

Unreliable Service, does not require other client to acknowledge. Used for Video Chat, DNS, DHCP, Games and others that is typically used for a environment that is used to broadcast their message to who ever is listening. Faster

What is well known TCP and UDP Ports

Up to 1023

What is each Layer PDU called?

[Transport:] Segment. [Network:] Packet. [Data:] Frame [Physical:] Bits

What is the command for entering the plain text password for encrypted? Is it strong? What about the other command? What type is it?

serivce password-encryption <7>... enable secret <command> <5> No its not, only designed to prevent over the shoulder viewing. MD5

How to find a switch that is connected to a switch in your current switch?

sh cdp neighbors. Cisco Device Protocol

What part would see see if the router has been reached full capacity or bottlenecking?

show interfaces fa x/x under output queue.

What command do you use to view the contains for the Duplex, Encapsulation, CRC Errors. What should you never see in this under a full duplex?

show interfaces fa x/x. Collisions / Late Collisions. Difference is normal is within first 32 bytes, Duplex collisions usually due to HUBs. If going beyond that, its a duplex mismatch.

When it asks for a website it does not know, what does it ask for? (UDP)

A johndoe.com.home.local (ipv4) AAAA johndoe.com.home.local (ipv6) A johndoe.com then ip.

How do you add port security? What can you do?

Must be in switchport mode access on a interface. Then can place as "switchport port-security." Can set maximum max addresses, the age. can manually put in MAC addresses, or have the switch learn them and keep them only. Can either protect, restrict or shutdown. Default security commands will not show in running config

What 2 types of Special Addresses must be accounted for when designing an IP address?

Network and Broadcast

Can a DHCP broadcast outside a router?

No, unless the router was given a command DHCP Relay.

What is happening when a interface in show running-config is displaying "Err-Disable."

Port shutdown due to security measures in place. Two types put things in place, either Port Protect or Port Restrict. Restrict will only tell you. Only way to turn it back on when its on "shutdown" option is to shutdown the interface and turn it back up.

Why does VTY and Aux have 'Login' when first turned on?

Prevents hackers from coming in and ruining your network. Without Password, does not allow person to log on.

To add SSH what are the type of Keys? What version is preferable? What is the minimum bit type and what other specifications does it require to continue? Can you add both SSH and telnet at same time.

RSA, Version 2. 360-bit needs to be in a ip domain, requires username and password to reach the domain. Requires to change transport input on different vty. Lastly, change to "Login Local" or Login Tacacs in the vty. Yes.

What is TCP? What is it typically used for? Is it fast or slow?

Reliable Service. More Overhead in packet. Delay, 3 way handshake, requires acknowledgement and consistent communication. Chats, Remote, Websites, Emails. Slower

What is Runts, Giant, Babble or CRC Error?

Runts: Packets that were not fully received. Kind of like two people talking thinking the other was done, but was not fully done after all. And they keep repeating that. Giant: Frame above the MTU size. Possibly dot1q attempt or MPLS frame, or another configured for jumbo frames. Babble: Attempting to send more frames then the other can receive. CRC: Bad Cable, light being interfered.

What does a website do in the background to establish a connection and transmit information?

Sends ARP to router, which sends information to server over a series of routers. [Computer SYN.] [Server Syn. Ack.] [Computer Ack.] Syn is a calling card to the server/client to get ready. Ack is "Acknowledge" every / 1.5 Kb packet. It gets bigger as the "windows" size is able to handle the transfer without dropping packets (sends 1 packet then 2 and so on). Hence you see 10k/b then 512k/b then 1.6m/b then drops at 1.3k/b on your application. but repeats this constantly trying to send more. Each time it sends a sequence number to show where they are at (keep track where they are in 'talking'.) If it cannot keep up, it will resend the sequence it missed. Once its done they both do Fin.

What is Static Addresses Typically Used For?

Servers (hosts) not clients