Netdisco

Overview

Nodes and Devices

• Devices are network devices such as routers, switches and firewalls

• Nodes are end-stations connected to devices such as pcs, servers, printers and ip phones

Jobs

• There are 4 principal job types:

  • discover: Gather information about a Device, including interfaces, vlans, PoE status, and chassis components (modules). Also learns about potential new Devices via neighbor protocols and adds jobs for their discovery to the queue. Read this for further information

    • Ping sweep: works with subnet, ping first, those responded will be added to job queue

  • macsuck: Gather MAC to port mappings from known devices reporting layer 2 reachability

  • arpnip: Gather Mac to IP mappings from known devices reporting layer 3 reachability

  • nbtstat: poll a node to obtain its NetBIOS name

Configuration

• There are two configuration files: config.yml (which lives inside the Netdisco package) and deployment.yml (which usually lives in ${HOME}/environments) such as: /opt/netdisco/environments/deployment.yml

Some settings

• device_auth: authentication for all polling

• device_identity: control cananoical name or identity of devices in Netdisco

• host_group_displaynames: assign host groups friendly names

Command

• perldoc ${HOME}/bin/netdisco-do: view document about netdisco-do command

• Backend Status: ${HOME}/bin/netdisco-backend status

• Daemon Status: ${HOME}/bin/netdisco-daemon status

• Start/Restart Webapp Server: ${HOME}/bin/netdisco-web start|restart

• Start/Restart Job Control Daemon: ${HOME}/bin/netdisco-backend start|restart: this start those job like device polling, port control, etc

• First manual discovery: ${HOME}/bin/netdisco-do discover -d $NameorIPofseedDevice

• Add ping sweep task to the queue: netdisco-do pingsweep -d 192.0.2.0/24 --enqueue

• Do task with debugging: netdisco-do discover -d $ipaddress -DIQ: D for debugging, I for SNMP::Info and Q for SQL tracing

• SNMP Community string is hidden by default, so to show it: SHOW_COMMUNITY=1 ~/bin/netdisco-do discover -d $ipaddress -DIQ

Netdisco-do

• Dump an SNMP object for a device:

~/bin/netdisco-do show -d 192.0.2.1 -e interfaces
~/bin/netdisco-do show -d 192.0.2.1 -e ::interfaces
~/bin/netdisco-do show -d 192.0.2.1 -e Layer2::HP::interfaces
~/bin/netdisco-do show -d 192.0.2.1 -e all: show all information
~/bin/netdisco-do show -d 192.0.2.1 -e cdp_dev_id: show cdp_dev_id information

• Interactive SQL terminal on Netdisco DB

~/bin/netdisco-do psql
~/bin/netdisco-do psql -e 'SELECT ip, dns FROM device'
~/bin/netdisco-do psql -e 'COPY (SELECT ip, dns FROM device) TO STDOUT WITH CSV HEADER'

• See how Netdisco has parsed the configuration file

~/bin/netdisco-do dumpconfig
~/bin/netdisco-do dumpconfig -e $settingname
# device_auth and snmp_auth are not dumped by default
~/bin/netdisco-do dumpconfig -d 192.0.2.1 -e device_auth

Troubleshooting

Cisco Device - Device name doesn't match hostname

• When searching for device using device hostname, device is listed with a different name rather than its hostname.

• Cause: This is because it has a DNS A or PTR record with that name. Solution is changing it

• Cause: It doesn't have dns name, but information is old. Delete it using netdisco-do delete -d $name and rediscover using netdisco-do discover -d $name

Reference

• Netdisco

• Netdisco Configuration

• Vendor Tips

• Netdisco Troubleshooting