Describe the Switch Fabric
- Allows a packet to move from the I/O card (Data Plane) where it enters the Service Router to the I/O card where it needs to exit the router
- Allows a control packet to move from the I/O card where it enters the router to the Control Processing Module (CPM) card where it needs to be processed
- Allows a control packet to move from the CPM to the I/O card where it needs to exit the router
What are the different types of Input/Output Cards?
- Input/Output Module (IOM) & accompanying Media Dependent Adapter (MDA) cards
- Integrated Media Module (IMM) cards
- eXpandable Media Adapter (XMA) cards
What are the different types of Input/Output Cards?
- Input/Output Module (IOM) & accompanying Media Dependent Adapter (MDA) cards
- Integrated Media Module (IMM) cards
- eXpandable Media Adapter (XMA) cards
What is the order of data packet flow when egressing a Nokia 7750 SR?
SF/CPM -> IOM -> MDA -> SFP
What are the files required for the Nokia 7750 SR boot process?
- Boot Loader file (boot.ldr)
- Boot Options File (bof.cfg)
- Directory where the software image is loaded
- Configuration File (config.cfg)
What information is contained in the bof.cfg file?
- Management Port IP Address
- Location of the primary, secondary, and tertiary image files
- Location of the primary, secondary, and tertiary configuration files
What information is contained in the config.cfg file?
Commands to configure cards, ports, layer-3 interfaces, routing protocols, MPLS tunnels, VPN services, QoS, and anything else configurable within the Nokia SR OS
What are the steps taken when a Nokia SR OS system is being initalized?
- Load & Execute the boot loader (boot.ldr)
- Read & Apply the BOF initialization parameters (bof.cfg)
- Get the runtime software image file from one of the specified locations
- Once the SR OS is running get the configuration file (config.cfg) and execute the commands.
What are the 3 management interfaces for SR OS devices?
- Classic: only classic commands, using either CLI or SNMP interfaces (default)
- Model-Driven: only model-driven commands for config changes, using either MD-CLI, NETCONF, or gRPC/gNMI interfaces. also read-only access to CLI & SNMP classic interfaces
- Mixed: Read/Write access to both classing & MD management interfaces (With limitations)
What configuration edit modes are available in MD-CLI?
- Global: Allows a user to see and modify the global candidate configuration in a non-exclusive mode
- Exclusive: Allows a user to modify the global configuration in an exclusive mode, but other users can see the changes being made
- Read-Only: Allows a user to see the changes being made by other users, in either global or exclusive mode, to the global candidate configuration
- Private: Allows a user to create their own private candidate configuration in an exclusive mode; no other users can see or modify the private candidate configuration.
What are the 4 types of event categories?
- Security: Related to attempts to breach system security (e.g. failed logins)
- Change: Related to changes in the config and operation of the node
- Debug: Generated due to debug commands issued by the administrator
- Main: All other events
What are the 6 severity levels of events?
- Cleared
- Indeterminate (information only)
- Critical (most severe)
- Major
- Minor
- Warning (least severe)
What destinations are available for event logging?
- Console: Sent to the active session on the system console
- CLI: sent to the active telnet or SSH session of users who subscribe to receive messages
- File: Sent to a circular file in the compact flash cards (old data is overwritten)
- Memory: Sent to a circular buffer in memory
- Syslog: Sent to a syslog server identified by its IP address
- SNMP: set to SNMP trap receivers
- NETCONF: sent to the active NETCONF session as notifications
What are the steps to configure an event log?
- Create an event log with an ID between 1 and 97 (98 - 100 are reserved)
- Select the categories of events that will be registered (one or more)
- Optional: configure & apply a filter to be more specific about the event messages of interest regarding their severity, corresponding application, or whether they include/exclude some words
- Select the destination of the event log
What are the pre-configured default event logs?
- log-id 99: Default System Log
- log-id 100: Default Serious Errors Log
- log-id 101: netconf
What are the cli commands to modify the bof (boot options file)?
edit-config bof exclusive
bof router “management”
interface “management” cpm active ipv4 ip-address 172.16.2.4
interface “management” cpm active ipv4 ip-address prefix-length 27
static-routes route 128.0.0.0/1 next-hop 172.16.2.1
commit
What is the CLI command for configuring the system name?
configure system name “new_sys_name”
commit
quit-config
What are the main functions of the control plane?
- Support management functions of the router
- build the forwarding table information
- handled routing protocols messaging
What are the main functions of the data plane?
- Receive, process, and transmit user application traffic using the forwarding tables populated by the control pane
What is a managment datastore and how many types are there in a Nokia 7750 SR?
It is a tree-shaped data structure where management information is stored and there are 2 types
- Configuration datastore
- State datastore
