SD-WAN Sites Test

The Citrix SD-WAN provides resilient and robust connectivity between remote sites, data centers, and cloud networks. To accomplish this, the tunnels between SD-WAN appliances in the network are established and connectivity between WAN sites is enabled by leveraging route tables that overlay the existing underlay network. SD-WAN route tables can fully replace or coexist with the existing routing infrastructure. The SD-WAN configuration allows static route entries for specific sites, and route entries learned from the underlay network through supported routing protocols; such as OSPF, eBGP, and iBGP. Routes are not only defined by their next hop but by their service type. This determines how the route is forwarded. Below are the main service types in use:

  • Local Service - This service denotes any route or subnet local to the SD-WAN appliance. This includes the Virtual Interface subnets (automatically creates local routes), and any local route defined in the route table (with a local next hop). The route is advertised to other SD-WAN appliances that have a Virtual Path to this local site where this route is configured when trusted as a partner.

    Note:

    Be cautious when adding default routes, and summary routes as local routes as these can result in virtual path routes at other sites. Always check the route tables to make sure the correct routing is in effect.

  • Virtual Path - This denotes any local route learned from a remote SD-WAN site; that is what is reachable down the virtual paths. These routes are normally automatic, however a virtual path route can be added manually at a site. Any traffic for this route is forwarded to the defined Virtual Path for this destination route (subnet).

  • Intranet - This service denotes routes that are reachable through a private WAN link (MPLS, P2P, VPN etc.). For example, a remote branch that is on the MPLS network but does not have an SD-WAN appliance. It is assumed that these routes need to be forwarded to a certain WAN router. Intranet Service is not enabled by default. Any traffic matching this route (subnet) is classified as intranet for this appliance for delivery to a site that does not have an SD-WAN solution.

    Note:

    Notice that when adding an Intranet route there is no next hop, but rather a forward to an Intranet Service. The Service is associated with a given WAN link.

  • Internet -This is similar to Intranet but is used to define traffic flowing to public Internet WAN links rather than private WAN links. One unique difference is that the Internet service can be associated with multiple WAN links and set to load balance (per flow) or be active/backup. A default Internet routes gets created when internet service is enabled (it is off by default). Any traffic matching this route (subnet) is classified as Internet for this appliance for delivery to public internet resources.

The above-mentioned service types play an important role in defining the routes among remote sites, data centers, and cloud networks and handling traffic among them. To ensure better performance and user experience in the SD-WAN environment, therefore, it is important for administrators to continuously check the traffic handled using each type of service. By continuously monitoring the data/packet transmission using each service type, administrators can find out which service type is efficient in handling traffic flow between the WAN and LAN connections. For this purpose, administrators can use the SD-WAN Sites test.

This test monitors all the type of services used to transfer data/packet in the SD-WAN environment, and reports the rate at which the data/packets were transmitted/received and the data/packets dropped while transmitting/receiving using each type of service. These statistics are useful for administrators to find out the type of service on which heavy traffic or slowness was reported at the earliest and prevent the traffic congestion that may affect the business -critical transactions.

Target of the test : A Citrix SD-WAN

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each type of service on which multicast traffic will be sent to or receive from the WAN sites.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed. By default, this is set to 5 minutes.

Host

The IP address of the target SD-WAN appliance for which this test is to be configured.

Port

Refers to the port at which the target SD-WAN listens to. By default, this will be NULL.

Timeout

Specify the time duration (in seconds) beyond which this test should time out in the Timeout text box. The default is 10 seconds.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

LAN to WAN data transmission

Indicates the rate at which the data was transmitted from LAN to WAN on this service type.

Mbps

 

LAN to WAN packet transmission

Indicates the rate at which the packets were transmitted from LAN to WAN on this service type.

Packets/sec

 

LAN to WAN data dropped

Indicates the rate at which the data was dropped while transmitting/receiving data from LAN on this service type.

Mbps

Ideally, the value of this measure should be zero.

LAN to WAN packets dropped

Indicates the rate at which the packets were dropped while transmitting/receiving packets from LAN to WAN on this service type.

Packets/sec

Ideally, the value of this measure should be zero.

WAN to LAN data transmission

Indicates the rate at which the data was transmitted from WAN to LAN on this service type.

Mbps

  

WAN to LAN packet transmission

Indicates the rate at which the packets were transmitted from WAN to LAN on this service type.

Packets/sec

 

WAN to LAN data dropped

Indicates the rate at which the data was dropped while transmitting/receiving data from WAN to LAN on this service type.

Mbps

Ideally, the value of this measure should be zero. Compare the value of this measure across the service types to find out the service type on which more data loss was reported while transmitting/receiving data.

WAN to LAN packets dropped

Indicates the rate at which the packets were dropped while transmitting/receiving data from WAN to LAN on this service type.

Packets/sec

Ideally, the value of this measure should be zero. Compare the value of this measure across the service types to identify the service type on which too many packets were dropped while transmitting/receiving the packets.