NetPath graph issue: Missing Internet nodes when connection reaches endpoint

10/19/2018 6:41 PM

7/20/2022 12:46 AM

The NetPath graph seems to be missing Internet nodes.

The NetPath graph has no timeout nodes, but many intermediate nodes are missing. For the external endpoint, the traces jump directly from an internal node to the endpoint without any nodes from ISP networks.

Network Performance Monitor

Step 1: Check the number of nodes between the NetPath probe and the endpoint

How many nodes are there?

• One: Go to step 2.
• More than one: Go to step 3.

Step 2: Check if the NetPath probe is running on VirtualBox with NAT enabled

1. Open VirtualBox if the NetPath probe is running there.
2. Click Settings > Network.
3. Click the tab of the outgoing adapter, and check the value of the dropdown labeled Attached to.

   

Is the NetPath probe running on VirtualBox with NAT enabled?

• Yes: This is a known limitation due to VirtualBox resetting the TTL of outgoing packets. To work around this, change to a Bridged Adapter in Settings > Network.
• No: Go to step 3.

Step 3: Check the NetPath graph for the same endpoint but non-web traffic

1. Create a new service for the same endpoint on the same NetPath probe, but with the following settings:
   • Five-minute interval
   • A well-known non-web port, such as 25 or 53 (It is OK if those ports are not open on the endpoint)
2. Wait 5 - 10 minutes, and then check the graph.
3. Check if the graph contain external nodes, or if it has the same problem without any external nodes.

Does the graph contain external nodes?

• Yes: Go to step 5.
• No: Go to step 4.

Step 4: Recheck the probe and endpoint distance from step 1

Is the distance less than or equal to one?

• Yes: Go to step 5.
• No: Submit a ticket to technical support.

Step 5: Check if the next node gateway has proxy or WAN optimizer enabled

1. Do you have access to the default gateway configuration?
   • Yes: Check if the proxy or WAN optimizer is enabled.
   • No: Skip to the next step.
2. Run a Trace Route from the NetPath probe to the endpoint, and count the number of response nodes. Check if there is more than one response node.

Is the proxy or WAN optimizer enabled?

• Yes: This is a known proxy issue. See the following workaround:

  To see intermediate nodes:

  • Add the NetPath probe to the proxy white-list or add a pass-through rule for the NetPath probing traffic.
  • For Riverbed Steelhead, add a pass-through in-path rule. (©2018 Riverbed Technology, Inc., available at https://support.riverbed.com , obtained on November 19, 2018)
  • For Cisco WAAS with AppNav redirection (not WCCP or PBR), add a pass-through rule to the AppNav policies. (©2018 Cisco, available at http://www.cisco.com , obtained on November 19, 2018)
  • For Cisco ASA with NAT enabled, and if a Windows Trace Route from the NetPath probe returns multiple nodes with the same ASA interface IP address, see this article. (©2018 Astorino Networks, available at http://www.astorinonetworks.com , obtained on November 19, 2018)

  To see nodes from the proxy server to the endpoint:

  • Add the NetPath probe to the proxy server subnet. See Network paths in NetPath end early for more information.
• No: Submit a ticket to technical support.