Manual Layer 2 EtherChannel # Add the correct channel-group configuration command to each physical interface on each switch, all with the on keyword, and all with the same number. The on keyword tells the switches to place a physical interface into an EtherChannel, and The number identifies the PortChannel interface number that the interface should be a part of. EtherChannel, PortChannel, and Channel-group basically mean the same thing. channel-group number on the neighboring switch can differ. “Po1” is short for PortChannel1 Channel-group command cannot override the channel-protocol command Create the port channel:

Star: A design in which one central device connects to several others, so that if you drew the links out in all directions, the design would look like a star with light shining in all directions. Topology Terminology Seen Within a Two-Tier Design Full mesh: For any set of network nodes, a design that connects a link between each pair of nodes. Partial mesh: For any set of network nodes, a design that connects a link between some pairs of nodes, but not all. In other words, a mesh that is not a full mesh. Hybrid: A design that combines topology design concepts into a larger (typically more complex) design. twoand a partial mesh at the distribution layer.-tier design is indeed a hybrid design that uses both a star topology at the access layer The distribution layer creates a partial mesh. none of the access layer switches connect to each other. Three-Tier Campus Design (Core)

Connection Methods # Factory default login: # User: root No password

Tuesday, August 31, 2021 2:58 PM they re-add these routes when the interface is again in a working (up/up) state Examples of Local IPv6 Routes show ipv6 route local command

Monday, August 30, 2021 9:19 AM both abbreviated and unabbreviated addresses, and both lowercase and uppercase hex digits, showing that all are allowed. Enabling IPv6 Routing IPv6 routing is not enabled by default. routing —whichenables IPv6 routing on the router.The solution takes only a single command— ipv6 unicast- A router address) must enable IPv6 globally before the router will attempt to route IPv6 packets in and out an interface (ipv6 unicast-routing ) and enable IPv6 on the interface .If you omit (ipv6 theroute any received IPv6 packets, but the router will act as an IPv6 host ipv6 unicast-routing command but configure interface IPv6 addresses, the router will not. If you include the ipv6 unicastroute IPv6 packets but have no interfaces that have IPv6 enabled, effectively disabling IPv6 -routingcommand but omit all the interface IPv6 addresses, the router will be ready to routing Verifying the IPv6 Address Configuration The show ipv6 interface brief command gives you interface IPv6 address info, but not prefix length info, similar to the IPv4 show ip interface brief command. this command lists IPv6 addresses, but not the prefix length or prefixes. The show ipv6 interface commandgives the details of IPv6 interface settings, much like the show ip interface command does for IPv4. the IPv6 show interfaces. So, to see IPv6 interface addresses, use commands that begin withcommand still lists the IPv4 address and mask but tells us nothing about show ipv6

Friday, August 27, 2021 3:17 PM IPv6 Subnetting Using Global Unicast Addresses Most everyone uses the easiest possible IPv6 prefix length: /64. theright side of the IPv6, formally called the interface ID(short for interface identifier), acts like the IPv4 host field. the prefix length of the global routing prefix is often between /32 and /48, or possibly as long as /56. with the commonly used 64being the length of the global routing prefix.-bit interface ID field, the subnet field is typically 64–P bits, with P

Endpackets if the host is in a different subnet.-user hosts need to know the IPv6 address of a default router, to which the host sends IPv6 IPv6 routers de-encapsulate and re-encapsulate each IPv6 packet when routing the packet. IPv6 routers make routing decisions by comparing the IPv6 packet’s destination address to the router’s IPv6 routing table; the matched route lists directions of where to send the IPv6 packet next. Note You could take the preceding list and replace every instance of IPv6 with IPv4, and all the statements would be true of IPv4 as well.

example All open on one computer: Port 80 Web ServerPort 800 Ad Server Port 9876 Wire Application Socket Includes IP address, transport protocol, and port number (10.1.1.2, TCP, port 80) Multiplexing

All hosts act like they always have, with one default router setting that never has to change. The default routers share a virtual IP address in the subnet, defined by the FHRP. Hosts use the FHRP virtual IP address as their default router address. The routers exchange FHRP protocol messages so that both agree as to which router does what work at any point in time. When a router fails or has some other problem, the routers use the FHRP to choose which router takes over responsibilities from the failed router. The Three Solutions for First-Hop Redundancy First Hop Redundancy Protocol does not name any one protocol. Instead, it names a family of protocols that fill the same role

IP and TCP Header IP Header Misc Header Fields▪ 9 bytes ▪ 1 byte ▪▪ ie 6 = tcpidentify TCP header Protocol Header Checksum▪ 2 bytes ▪ 4 bytes Source IP Dest. IP▪ 4 bytes Options▪ variable TCP Header Source Port- 2 bytes 2 bytes Dest. port Rest of TCP- 16 bytes tcp or udp keyword

802.3 (Ethernet Standards 10BASE-T 10 MbpsEthernet 802.3Copper/ 100 m 100BASE-T 100 MbpsFast Ethernet 802.3uCopper/ 100m 1000BASE-LX 1000 MbpsGigabit Ethernet Gigabit Ethernet802.3z Fiber, 5000 m 1000BASE-T 1000 Mbps Gigabit Ethernet802.3ab Copper, 100m 10GBASE-T

Attacker replies with false dhcp information by naming itself as the default gateway Pc1 send all messages to another network to attacker, becoming a man-in-the-middle attack (pc2 could forward the messages to the actual default gateway

Thursday, September 30, 2021 12:17 PM Watch for incoming DHCP messages, with destination IP address 255.255.255.255Change that packet’s source IP address to the router’s incoming interface IP address.. Change that packet’s destination IP address to the address of the DHCP server (as configured in the addres scommand). ip helper-

To configure a router or switch to logging host {address | hostname } send log messages to a syslog server global command. *Dec 18 17:10:15.079: %LINEPROTOchanged state to down - 5 - UPDOWN: Line protocol on Interface FastEthernet0/0, A timestamp: *Dec 18 17:10:15. The facility on the router that generated the message : %LINEPROTO The severity level : 5 A mnemonic for the message : UPDOWN The description of the message: Line protocol on Interface FastEthernet0/0, changed state to down you can at least toggle on and off the use of thelog message sequence number (which is not enabled by default)timestamp (which is included by default). Example 9-1 reverses those and a defaults by turning off timestamps and turning on sequence numbers. Log Message Format

Friday, October 29, 2021 2:40 PM ○ Matching an Ethernet frame’s destination Media Access Control (MAC) address to the MAC address table (Layer 2 switches) Matching an IP packet’s destination IP address to the IP routing table (routers, Layer 3 switches) ○ # Encrypting the data and adding a new IP header (for virtual private network [VPN] processing) ○ # ○ Changing the source or destination IP address (for Network Address Translation [NAT] processing) ○ Discarding a message due to a filter (access control lists [ACLs], port security) The Control Plane any action that controls the data plane. creating the tables used by the data plane, tables like the IP routing table, an IP Address Resolution Protocol (ARP) table, a switch MAC address table, and so on. adding to, removing, and changing entries to the tables used by the data plane

Plug console cable in find out what your serial line name is: $ dmesg | grep -i FTDI Open putty > change to serial > change the tty line name Make sure your serial settings are correct

1.0 Network Fundamentals 1.1 Explain the role and function of network components 1.1.g Servers 1.2 Describe the characteristics of network topology architectures 1.2.f On-premises and cloud 1.12 Explain virtualization fundamentals (virtual machines)

IPv4 Address Classes Based on First Octet Values Class First Octet Values Purpose A 1–126 Unicast (large networks) B 128–191 Unicast (medium-sized networks) C 192–223 Unicast (small networks) D 224–239 Multicast

Reload Tells the system to reboot IOS Keyboard Shortcuts Recently used (Previous) up arrow or Ctrl+P Go back up from the above command (next) Down arrow or Ctrl+N Left arrow or - Move cursor (back) Ctrl+B Right Arrow or Ctrl+F- Move cursor (forward) Delete Back Space Debug

Can be used to match packets for applying Quality of Service (QoS) features. ACL Location and Direction inbound to the router, before the router makes its forwarding (routing) decisionoutbound, after the router makes its forwarding decision and has determined the exit interface to use.enable an ACL on an interface that processes the packet, in the direction the packet flows through that interface.the router then processes every inbound or outbound IP packet using that ACL Taking Action When a Match Occurs

6.0 Automation and Programmability 6.6 Recognize the capabilities of configuration mechanisms Puppet, Chef, and Ansible Configuration Drift The on-device manual configuration process does not track change history: which lines changed, what changed on each line, what old configuration was removed, who changed the configuration, when each change was made. External systems used by good systems management processes, like trouble ticketing and change management software, may record details. However, those sit outside the configuration and require analysis to figure out what changed. They also rely on humans to follow the operational processes consistently and correctly; otherwise, an engineer cannot find the entire history of changes to a configuration. Referring to historical data in change management systems works poorly if a device has gone through multiple configuration changes over a period of time. Centralized Configuration Files and Version Control

Friday, October 8, 2021 11:48 AM Quality of Experience (QoE) -users’ perception of their use of the application on the network. Voice and Video Applications Aflowisall the data moving from one application to another over the network, with one flow for each direction For example, if you open a website and connect to a web server, the web page content that moves from the server to the client is one flow. From a voice perspective, a phone call between two IP phones would create a flow for each direction Step 1. The phone user makes a phone call and begins speaking. Step 2. A chip called a codec processes (digitizes) the sound to create a binary code (160 bytes with the G.711 codec, for example) for a certain time period (usually 20 ms). Step 3. The phone places the data into an IP packet. Step 4. The phone sends the packet to the destination IP phone.

10 NAT # Friday, October 8, 2021 7:12 AM Network Address Translation Concepts Static NAT IP addresses statically mapped to each other.

Quick Commands Basic Device Management # SSH # crypto key generate rsa modulus (modulus value) show ip ssh show ssh DHCP # ip address dhcp show dhcp lease show interfaces vlan 1 show ip default-gateway History # show history terminal history size x history size x Logging and Domain Lookup # no logging console no ip domain-lookup exec timeout (minutes) data plane