This document describes how NetBrain can be used to troubleshoot and analyze network issues and changes. It provides examples of use cases where NetBrain allows users to map network components, monitor performance, compare configurations and routing tables, and automate documentation. Common challenges include lack of network visibility and difficultly tracking down issues. NetBrain provides solutions like dynamic diagrams, monitoring from maps, and change impact verification.

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NetBrain In Action
 Document Automation
 Visual Troubleshooting
 QA Network Changes
Real World Use Cases:

2. Step 1 » Map Application Flows.
Identify the source and destination of a
slow application and enter them into the
traffic path wizard.
Step 2 » Monitor From the Map.
Click the “Monitor” button in the map’s
floating menu, and launch performance
and connectivity diagnosis.
Step 3 » Analyze the History.
Click the “Compare” button to discover
what’s changed in configuration and
routing for the relevant devices.
 Congested WAN links
 High CPU/Memory
utilization of routers
 Unstable routing
 Asymmetric flows
 Speed/duplex mismatch
Performance metrics for an application are visualized in real-time
Challenges:
Solutions:
Common Causes:
 Lack of documentation
and historic data for
applications
 Difficult to visualize
network slowness
 Use Dynamic Diagram to
map out application
flows
 Diagnose from a map
Troubleshoot Slow Applications

3. Step 1 » Map L3 Connectivity.
Enter the IP address of a server in the
“Search” dialog, and click the “Map”
button in the search results.
Step 2 » Map L2 Connectivity.
Click the red “+” sign near the switch icon
and extend the neighboring switches and
routers in the same VLAN.
Step 3 » Launch Diagnostic Monitoring.
Click the “Monitor” button in the map’s
floating menu, and launch performance
and connectivity diagnosis.
 Broken cable
 Switch port in disabled
mode by spanning tree
or error-disable
 Server plugged into
wrong port
 Gateway Router not
functioning
 Misconfiguration
 Link down/flapping
A L2 Heat Map
 No up-to-date documents
about servers’ physical
and logical connectivity
 On-demand document
automation
Challenges:
Solutions:
Common Causes:
Troubleshoot Network Connectivity
A L3 Heat Map

4. Step 1 » Map Out Core Network.
Search the core devices by name and
group them into a device group. Map the
device group via the right-click menu.
Step 2 » Discover Flapping Routes.
Benchmark the routing tables of all core
devices. Then compare new routing tables
against the baseline. Discover modified
routes by smallest age.
Step 3 » Trace to the Source.
Drag-and-drop the route entry to the Q-
map, and trace to the source of instable
routes hop-by-hop.
 Link flapping
 Router CPU overload
 Routing peer reset
 Network worm attack
 Route flapping is
transient in nature –
difficult to catch and
pinpoint root cause
 Use routing table
analyzer
Drag-and-drop the entry to a Q-map
Challenges:
Solutions:
Common Causes:
Troubleshoot Route Flapping

5. Step 1 » Map a MPLS Cloud Network.
Drag-and-drop an MPLS cloud into a map
and extend key devices around the cloud.
Step 2 » Monitor From the Map.
Click the “Monitor” button in the map’s
floating menu, and launch performance
and connectivity diagnosis.
Step 3 » Detect Packet Loss via IPSLA
For advanced performance diagnosis,
right-click on hub routers and select the
IPSLA menu.
 QoS classification errors
 Physical errors at Demac
 Congested MPLS core
 Mismatch of CE-PE
configuration
 No visibility into a service
provider’s MPLS cloud
 Map-driven IPSLA
Toolkit
Challenges:
Solutions:
Common Causes:
Troubleshoot Packet Loss Across MPLS

6. Step 1 » Map Problem Area
Identify the source and destination of a slow
application and enter them into the traffic path
wizard.
Step 2 » Monitor to Identify Over-utilized Links.
Click the “Monitor” button in the map’s floating
menu, and launch performance and connectivity
diagnosis.
Step 3 » Drill-Down the Top-Talkers
Right-click on the utilization label, and select “IP
Accounting” to discover the top-talkers (assuming IP
accounting is turned on in the router).
 Unauthorized network
use
 Looping traffic caused by
misconfiguration
 Virus attack
 Difficult to pinpoint
congested links
 Time-consuming to setup
probes to track down
bandwidth-hogging devices
 Heat Map along with IP
Accounting
Challenges:
Solutions:
Common Causes:
Troubleshoot Bandwidth Hogging

7. Step 1 » Map the Existing Network.
Search devices to be modified and drag them
into a map. Right-click on the map’s “Auto Link”
menu to connect all devices.
Step 2 » Model the Future Network By
Importing Configuration Files
Drag new or modified device configuration files
into a map to model and visualize the future
network design.
Step 3 » Document the Design
Click the “Document” button in the map’s
floating menu and build an automated design
document in Word format.
 Analyze new network
design with Design Reader
 Highlight routing to
visualize design
 Very time-consuming to
document the network
before migration
 No visual help to plan
network migration
 Model network
migration based on
configuration files
Add a new network device
New
Document automation dialog
Challenges:
Solutions:
Related Features:
Plan Network Migration

8. Step 1 » Map the Change Area.
Search devices to be changed and drag
them into a map. Extend all neighbors
of the devices.
Step 2 » Benchmark Network Before
and After Changes
Click the “Benchmark” button, and
collect routing, configuration and L2
data before and after changes.
Step 3 » Verify the Impacts
Click the “Compare Config & Routing”
button, and compute routing table and
config changes for all devices.
 The comparative analysis
of routing, configuration
and traffic path should be
run after most network
changes – because 3 out
of 4 network outages are
caused by seemingly
benign changes
 A small change may cause
major impacts across the
entire network, but it is
difficult to check all
changes manually
 Automate impact
verification after each
network change
Detect routing changes after configuration modification
Challenges:
Solutions:
When to Use:
QA Network Changes to Prevent Outages

9. Step 1 » Discover a Data Center.
Enter a seed router’s IP address in the discovery
dialog and execute a data center discovery.
Step 2 » Map Device Groups by Automation
By combining dynamic search criteria, routers,
switches and servers can be grouped in many
ways to map a data center automatically.
Step 3 » Build Diagrams and Inventory
Reports
Click the “Export to Visio” and “Asset Report”
buttons in the menu bar, and create Visio
diagrams and inventory reports.
 Before and after a data
center upgrade
 Data center assessment
 It takes weeks or months
to discover and document
a data center with tracing
cables, show commands
and Visio
 Advanced discovery and
document automation
Challenges:
Solutions:
When to Use:
Document a Data Center Network

10.  Apply diagnostic
monitoring to VoIP paths
 Automate documentation
for VoIP assessment
 VoIP is very complex and
depends on many
advanced technologies to
work properly
 Automate the analysis
of network design and
performance
IPSLA Measurement
Map VoIP traffic path instantly
Challenges:
Solutions:
Related Features:
Assess a Network for VoIP Readiness
Step 1 » Map Key VoIP Traffic Flows.
Enter IP addresses of IP-phones and
voice gateways into the traffic path
wizard, and map out L3 and L2 traffic
flows for VoIP.
Step 2 » Measure Delay, Jitter and
Packet Loss Along Paths
Launch IPSLA from the map to measure
advanced performance metrics.
Step 3 » Analyze QoS Design
Launch “Design Reader” from the map
to decode QoS and VoIP configuration.

11. Step 1 » Discover Each Network
Independently
Build two workspaces – one for each network
by importing configuration files or through
discovery. Create two asset reports.
Step 2 » Analyze Overlap
Compare the asset reports to find overlapping
subnets and overlapping routing protocols.
Build maps to describe each conflict.
Step 3 » Merge Two Networks Virtually
Use one workspace as the base, open each Q-
map created in step 2 and design migration
steps one map at a time.
 Analyze the new
network design with
Design Reader
 Use Search to find the
information needed
 Two networks were built
without knowledge of the
other, and everything has
to be reevaluated to avoid
conflicts
 Plan the network merge
in a virtual environment
Compare the inventory data of two networks
Challenges:
Solutions:
Related Features:
Merge Two Independent Networks

12. Solutions:
 To visualize a denial-of-
service attack to the
network and servers
 To analyze suspicious
traffic from a vague host
 To isolate virus-infected
end hosts
 Network attacks can come
from anywhere, and they
are difficult to visualize
 Use Dynamic Diagram to
map out attacks and
take defensive action in
real-time
Map the attack from the outside
Challenges:
When to Use:
Defend Against Network Attack
Step 1 » Identify the Offending Hosts
Get the top-talkers from Netflow, IP
accounting or intrusion-detection
software.
Step 2 » Map Out the Attack
Use A/B path mapping or one-IP table to
map out the attack flow, whether it is
from the inside or outside.
Step 3 » Monitor the Traffic Flow
Launch the diagnostic monitoring on the
map and visualize the attack pattern.
Map the attack from the inside

13. Solutions:
 To prepare for CCIE
 To prepare for CCNP
 To prepare for CCNA
 It takes a long time to
become Cisco certified.
People can forget things
learned if not reinforced
properly
 Use NetBrain to
document practice labs
automatically and
review past labs visually
Challenges:
When to Use:
Become Cisco Certified - CCIE/CCNP/CCNA
Step 1 » Use NetBrain for Practice Labs .
Use NetBrain to automatically document practice labs
step-by-step. It’s easier to learn new skills in a map-
driven environment.
Step 2 » Review Essential Skills Through a Map
Along the journey towards certification, users can
review details of past labs without re-building them.
Step 3 » Form a Visual Study Group
Form a study group to share practice labs through Q-
maps so that everyone can save time. Visit network-
diagram.com for examples.