By Joe Habib, WildPackets Director of Global Services
OmniPeek is the first protocol analyzer to offer both expert diagnostics and frame decoding in real time, during capture. WildPackets’ OmniPeek has been carefully designed to help IT Professionals analyze and diagnose increasingly diverse volumes of network data, providing precise, contemporary analysis of the problems facing today’s networks.
Here are ten cool things you can do today with OmniPeek!
Main window of OmniPeek, showing the Expert view
1. Capture and view packets
Though you can see global network statistics without capturing packets, for most analysis sessions you’ll want to capture packets. One of OmniPeek’s many strengths is in its flexibility. This is immediately apparent in the packet list display, where you can easily customize the display.
1. Click the New Capture button on the Start Page, or pull down File…New from the menu bar. Click OK in the Capture Options Dialog, then click the Start Capture button.
2. OmniPeek provides several ways to customize your view of traffic with a single click.
a. The auto scroll option (Ctrl-K) allows you to see packets as they come in, which is useful if you’re looking for particular information in the Summary or Expert columns.
b. The Show Packet List, Show Decode View, and Show Hex View buttons allow you to pick the content you want to see in real-time. Most other analyzers show all three (and not usually in real time) and do not allow you to toggle between the different views.
c. Right-click on one of the columns in the packet list to customize the column display.
2. Capture filtering the easy way
OmniPeek ships with a set of common, pre-defined filters, but its real power is in the ease with which you can create your own filters.
1. As packets are coming in, choose something you might want to filter on, such as a protocol or source IP address. Right click on that packet (stop the scrolling, if necessary, by keying Ctrl-K).
2. Click on Make Filter – notice that the information on the packet you chose is already set up in the Edit Filter dialog for you.
3. Name the filter and make modifications. You may wish to restrict the data to only one attribute, for example, source IP address or protocol.
4. Click OK to save the filter.
5. Click on the Filters tab and find your new filter in the list. Check the box next to the filter. You will now be capturing only packets that meet the criteria of that filter. (Alternatively, you can reject only those packets matching the filter criteria by clicking on the Reject Matching button.)
6. Go back to the packet list in the Packets view. You should only be seeing packets that meet your filter criteria. Notice the packet counts differ in the upper left corner (Packets Received vs. Packets Filtered)
3. Advanced filtering
OmniPeek’s advanced filtering is easier to use than most analyzers’ simple filtering. Filtering on specific protocol decode fields, for example, can be accomplished in just a couple of mouse clicks. Suppose you wanted to view all packets with a Time To Live (TTL) of under 128. A packet with a TTL of less than 128 indicates the packet has most likely traversed a router. When dealing with network slowdowns, it’s interesting to understand where the packet came from and where it’s going. TTL helps us understand the packet’s path. Here’s how to build the filter:
1. Click on the Packet List Tab.
2. Choose any IP packet and double-click to open the decode view.
3. Right click on the TTL field under the IP Header section and select k.
4. An advanced filter is already made for you!
5. Double click on the Value box.
6. Change the Operator to ‘<’ (other LAN analyzers do not have this capability).
7. Name the filter and click OK.
8. Go to the Filters Tab and click on the filter you just created. Packets will then be filtered on the fly!
9. The same filter can be used for post capture analysis, too. OmniPeek doesn’t force you to define filters in multiple places.
4. Who are the Top Talkers?
Top Talkers is a common troubleshooting statistic. The network is slow, for example, and you may want to see which stations are using the most bandwidth.
1. Click on the Nodes Tab. By default, the View Type is Hierarchical, where logical addresses and symbolic names are nested beneath their physical addresses along with their transmit and receive statistics. However, you can easily change the default view to one showing the Top Talkers.
2. Pull down IP from the View Type, then click on a column to sort on Bytes or Packets sent or received. Right click on the columns to customize the display.
3. To view a subset of the talkers, choose a value in the Display Top drop down.
4. Note that you can see the top 5 or 10 or 100, etc. Double click on a host to view its protocols in Detail Statistics.
Make a filter, build an alarm, or construct a graph for any of these hosts with just a click of the mouse. OmniPeek provides you with an amazing amount of flexibility. Other analyzers decide for you what statistics will be displayed.
5. What protocols are on your network?
Perhaps, instead of wanting to know what users are using the most bandwidth, you want to know what applications are using up bandwidth. Are any protocol ratios too high? Are there any protocols that shouldn’t be on the wire?
1. To see which applications are on your network, click on the Protocols Tab.
2. Double click on a protocol to see the % of usage by each host.
3. Return to the Protocols Tab, right click on a protocol, and Select Related Packets. This is a two-click method of choosing all the packets in the packet list that are talking this protocol. Select Related is available throughout the program: the nodes stats, expert problems, Peer Map, etc.
6. Make multiple graphs
OmniPeek’s extensive graphing ability enables you to correlate useful statistics. For example, are broadcast packets a significant portion of your utilization?
1. Click on the Summary Tab.
2. Right click on Total Broadcast, and choose Graph… Name the graph in the Graph Data Options dialog and click OK.
3. Right click on Average Utilization and choose Graph… Name the graph in the Graph
Data Options dialog and click OK.
4. Minimize the capture window and then choose Window…Tile Horizontally. (OmniPeek is one of the few analyzers that complies with MS Windows conventions, which is certainly helpful here!)
7. Find problem packets through “Select Related”
OmniPeek Expert Tab is by far the easiest to use and most up-to-date on the market. Problems are arranged by conversation, rather than by OSI model level. ProblemFinder tests and settings are just one right click away, as are problem descriptions and possible remedies. Other analyzers force you to hunt and peck for the information you need. OmniPeek delivers this information to you automatically. It pinpoints the packets related to a network communications issue, tells you why it’s probably happening, and suggests ways to fix the problem.
1. Click on the Expert Tab.
2. Right click on the first host, and choose Expand All.
3. Scroll down until you find a particular problem you’d like to look at.
4. Right click and choose Select Related Packets by Source and Destination or by
5. Alternatively, you can go straight to the Problem Summary Log and select all packets related to a particular problem. Note how the conversations having this issue are highlighted when you return to the Packets view.
8. Determine Application Response Time
Application Response Time is available via the Expert Tab, where detailed round trip analysis of command-response packets is available, showing you the
best, worst, and average delay. In a similar fashion, throughput is also analyzed.
1. Click on the Expert Tab
2. Click on the Node Details tab.
3. Right click on the first host in the conversation tree, and choose Expand All.
4. Walk down the tree until you see an interesting analysis in the Delay and Throughput
Analysis display in the lower right.
9. Visualize your network with expert mapping
The Peer Map is a great way to get a visual perspective of your network. Not only can you select related packets from hosts on the map, but you can easily create ad hoc filters or look at Top Talkers.
1. Click on the Peer Map.
2. Choose IP Map from the Map Type pull down in the upper right hand corner.
3. In the Node Visibility Criteria area just below, you can choose Top Talkers via absolute number or, say, top The amount of traffic through a node is represented by the size of a dot. If there is one host, such as a mail server or a web server that is skewing the results you are looking for, you can drag that node into the
10. Find that slow web server fast
With OmniPeeks’ Expert System, you can easily spot slow servers. Here’s an example of how to troubleshoot a slow web server.
1. Start a new capture.
2. OmniPeek ships with many standard filters, including HTTP. Click on the Filters Tab
and check the HTTP filter to immediately activate it.
3. Go back to the Packets view. Enable Scrolling (Ctrl-K) so you can see incoming packets. Verify that they are HTTP packets.
4. You may see HTTP access from web traffic not associated with your web server, so you will need to add a new filter. Open a browser and go to your web server. You should see your web server in the packet list display. Create a filter by right-clicking on that packet and choosing Make Filter.
5. Go to the Filters Tab and enable the filter you just created.
6. Now go to the Expert Tab. Click the Problem Summary pane and check for TCP Resets or HTTP Slow Response time diagnoses.
7. The Problem Log pane provides more detail, including actual time delay between specific packets (e.g. 13 seconds from Packet 908).
8. Right click and select related packets by See Packet.
9. Go to the Packets view and your problem packet is highlighted!
10. From there, try and figure out what sort of packet it is. Does it say Data in the Summary Column? What is this packet in response to? Click through the packets that preceded the bad packet.
Unlike other analyzers, OmniPeek’s expert system ignores the ACKs when determining the HTTP Slow Response diagnosis. Look to see if the ACK was received right away. If so, and it was the data packet that triggered the diagnosis, you know it was the web server that was slow and not the network.
Director of Global Services
I like to follow the KISS principal (KEEP IT SIMPLE STUPID) and welcome problems as they provide me with daily challenges.