Flashcards #1
VRRP Roles & Priority Order
Master and Backup. Highest Priority is the Master
HSRP Roles & Priority Order
Active and Standby. Highest Priority or IP adress is Active
What is an example of an Agentless Automation Tool?
Ansible
What Protocol does OSPF use to communicate?
Protocol number 89.
Protocol numbers are not the same as Layer 4 TCP or UDP port numbers. Rather, protocol numbers run directly on top of IP at Layer 3
OSPF States
Full State : Between the neighbor routers and the DR and BDR
2-Way State/ DROTHER : All other Routers remain in this state with each other
OSPF Transitions
- Down
- Init
- 2-Way
- Extart
- Exchange
- Loading
- Full
What Best Describes a Cisco TrustSec SGT?
is a means of classifying Traffic and is assigned to a user or a device.
TrustSec uses role-based security group policies instead of traditional ACLs to restrict access to network assets
Which method of WPA is a PSK used?
Personnal Mode
What are the first three ciriteria used by a BGP rotuer to determine the best path to a destination?
- Highest Weight
- Highest Local Preference
- Locally originated paths over externally originated paths
What types of OSPF networks require the manual configariotn of neighbor routers?
point-to-mulitpoint nonbroadcast
non broadcast.
Automatic neighbor discovery relies on broadcasts and multicasts, which are not allowed on nonbroadcast networks
What are the five OSPF network Types?
- Broadcast
- Non-Broadcast
- Point-to-point
- Point-to-multipoint broadcast
- Point-to-mulitpoint nonbroadcast
What Routing Protocol is used to create the underlay network in the Cisco SD-Access architecture when LAN automation is confured in CSICO DNA Center?
IS-IS
What is the default MTU of a physicaly interface?
1500 bytes
a 20-byte IP header and 1480 bytes of payload.
What are the two main concepts of CEF?
The FIB & Adjacency tahles
What networking mode will allow a VM to connect directly to an internal NIC by bypassing the host OS network stack?
Bridged.
Bridged networking mode enables a VM running on a Type 2 hypervisor to function similarly to a VM running on a Types 1 hypervisor with regard to network Access.
What is a Type 1 Hypervisor?
Is installed on a bare metal server, meaning that the hypervisor is also its own IS. A Type 1 hypervisor does NOT rely on a host OS
What is a Type 2 Hypervisor?
an application that is installed on a host OS, such as Microsoft Windows, macOS, or Linux. Also referred to as hosted hypervisors, use calls to the host OS to translate between guest OSs in VMs and the server hardware.
Link Aggregation Control Protol (LACP). Is this Cisco propriety or standards based protocol?
What are the modes?
Standard Based Protocol. Can be used between Cisco and non-Cisco switches.
Active and Passive
Port Aggregation Protocol (PAgp). Is this Cisco proprietary or standards based protocol?
What are the modes?
Cisco-proprietary. can only be used between two Cisco switches.
Auto and Desirable
What is INTER-controller roaming?
Roaming from a lightweight access point (LAP) to another LAP that is connected to a different wireless LAN Controller (WLC).
If WLC1 and WLC2 are on the same subnet, this is Layer 2 roaming
What is INTER-controller roaming when changing subnet?
Roaming from a lightweight access point (LAP) to another LAP that is connected to a different wireless LAN Controller (WLC) and different subnet. Called Layer 3 Inter-controller Roaming.
WLC that you are going from will acquire the anchor role, and the WLC that your are going to will assume the foreign mobility role.
What is INTRA-controller Roaming?
Roaming from a lightweight access point (LAP) to another LAP that is connected to the same wireless LAN Controller (WLC).
As long as both LAPs are using the same SSID, this type of roaming is seamless ot the end user.
What is the CEF adjacency table?
A CEF data plane table that stores information for network nodes that can communicate over a single link-layer hop
What is the CEF FIB table?
A CEF data plane table that is created by using a copy of the routing table (RIB).
Stores the mappings between network prefixes and outbound interfaces in a similar fashion to the Routing table
What is the RIB?
Another name for the Routing table, whcih stores paths to network destinations
Explain vSmart…
vSmart controller manages the control plane of the SD-WAN overlay network architecture.
The vSmart controller uses Overlay Management Protocol (OMP) to distribute routing information, security keys, and policy configurations through DTLS tunnels to vEdge routers. The vEdge routers can then use this information to determine the appropiate next hop for data plane traffic.
Explain vBond Orchestrator…
Authenticates vEdge routers and vSmart controllers over a Datagram Transport Layer Security (DTLS) tunnel connection as they perform their initial statup sequences.
It is the only SD-WAN component required to have a public IP address. The vBond orchestrator uses load-balancing mechanisms to ensure that vEdge routers are efficiently distributed betwen available vSmart controllers when the vEdge are initially configured.
Explain vManage
vManage NMS is a software solution that provides a single GUI to confiure and manage the components of the SD-WAN architecture. Additional software services can be added to vManage NMS to provide capabilities specifc to SaaS application performance monitoring or to netowkr performance data analysis.
Explain vEdge Routers…
They manage the data plane of the SD-WAN overlay network. The IP fabric of the SD-WAN overlay netowrk consists of vEdge routers interconnected by IPSec tunnels. Routing information for the IP fabric is reflected by using OMP to each vEdge router over a DTLS tunnel to its associated vSmart controller. Routes refelceted from the vSmart controller are redistributed into the routing table at each associated vEdge router so that all routing decisions can be handled locally by the vEdge routers.
What are the Severity levels (numbered 0 - 7)
- Emergencies
- Alerts
- Critical
- Errors
- Warnings
- Notifications
- Informational
- Debugging
Messages are formatted starting with % sign:
% followed by a facility code, a secerity code, and a mnemonic code. Three codes seperated by dashes then human readable text:
%Dual-5-NBRCHANGE:
What is a Rendezvous Point in Multicasting?
a Device (usually a router) that the devices will ask to be part of a group, so the they receive the desired traffic.
An RP is a well-connected, centrally located router that is responsible for keeping track of multicast group membership information.
What is IGMP?
IGMP allows a device to join a Multicast Group.
Internet Group Management Protocol
IGMPv1: Device will be pruned off session after 60 seconds of no response
IGMPv2: Device can request to leave Multicast group
IGMPv3: Device can request specific source of group (Works out bandwidth limitations of coming from one over the other.)
What is RPF?
Reverse Path Forwarding. Stops the flooding of the same frame arriving at the receiver.
The last hop router can run a RPF check against its routing table, and will only accept multicast message from that interface, and drop other multicast messages from other interfaces.
Difference between PIM Dense Mode and PIM Sparse Mode?
The routers running in PIM DM assume that everyone wants the receive the Multicast traffic, so will flood. If a Router can tell that the device on its link isnt a receiver and doesnt want the traffic it will prune.
PIM SM wil use a Rendezvous Point to avoid this flooding behaviour. so instead of flooding Routers will send a Join message to the Redezvous Point only. Once Receiver receives first packet throguh RP, The router recognises from the IP routing table that there is a quicker way back to the source, so sends out another JOIN request to the better router to say we want to come through you. RP just gets used tempoarily.
What is LISP
LISP is a protocol that is used with SD ACCESS. Converts the overlay to a PULL model. If Underlay is running OSPF, the devices alway s have to PUSH the updates to each out he about new networks. LISP works so that when a device needs to find another device, it can pull that nof it needs when it needs it.
What are the following:
ITR
ETR
PITR
PETR
LISP site to LISP site:
ITR: Encapsulates
ETR: De-encapsulates
These functions can be combined into a device known as xTR (Tunnel Router)
Proxies are used for communicating with Non-Lisp Networks:
PITR: Proxy Ingress Tunnel Router - Handles traffic from non-LISP sites destined for EIDs
PETR: Proxy Egress Tunnel Router - handle traffic from EIDs destined for non-LISP sites
What does the following command mean?
aaa authentication login default group tacacs+ local
The default authentication method is applied to all lines for which no other login method has been specified.
aaa authentication login …default…then list name for list of authentication methods
What command would you use to use to enable the Cisco IOS IP SLA Responder for UDP echo or jitter operations?
ip sla responder udp-echo ipaddress
What protocol number is used to identify GRE traffic?
47
GRE packets are encapsulated in IP packets and identified by the protocol number field within the IP header. The protocol number must be a value specified by the IANA. Common IP protocol numbers include the following:
1- ICMP 6- TCP 17- UDP 47- GRE 50- ESP 51- AH
what does the command service password-encryption do?
all current and future Type 0, or clear text, password are encrypted as Type 7 passwords in the devices running configuration.
