Overview… properties
Ports, modules, and the chassis itself have various settings and information, which you access under the “Properties” tab in the content area of the XenaManager after clicking on the appropriate resource in the navigation area.
The most commonly used are port properties:
On the left you have the reservation button, and on the right you have some basic information about the port such as its speed and interface type.
There is a section with settings relevant for Layer-2, the Ethernet layer itself:
The minimum inter frame gap specifies how tightly packets are spaced at 100% load. Note, that this also includes the Ethernet ‘preamble’ - the inter frame gap is considered to be all the space between the end of one packet and the beginning of the next one.
The MAC address is a 6-byte Ethernet address that is used by default as the source address of outgoing packets.
MAC training means that the port will periodically send packets even when traffic generation is off, to announce its MAC address to the nearest switch.
The port can be configured to react to incoming PAUSE frames, which will then cause a brief suspension of outgoing packets.
There is a section with settings relevant for Layer-3, the IP protocol layer:
You can specify a set of IPv4 address parameters, which are used by default as the source address of outgoing IPv4 packets, and also when using ARP to set the destination MAC address of a packet header.
You can select whether the port itself should respond to incoming ARP and PING requests. You can use wildcards on each IPv4 address component, and thereby simulate the presence of a whole range of IPv4 nodes.
Finally, there is a section with various port-level functions:
The loop modes include:
- RX-to-TX: incoming packets are sent back out from the port, and internal traffic generation is ignored. This makes the test port loop external traffic and still be able to analyze it.
- TX-to-RX: outgoing packets are sent back into the port, and received external traffic is ignored. This is an internal traffic loop and is useful for debugging stream configurations.
- Port-to-port: like RX-to-TX but for pairs of ports like 0+1, incoming packets from each port are sent back out on the other. This allows you to put the tester in-line on a link and intercept and analyze the traffic.
There is a latency offset, which is subtracted from the absolute latency measurements for the port.
The gap monitor makes the port look for any interruptions in a steady train of incoming packets:
- Start, specifies the maximum number of microseconds allowed between packets before starting a gap event.
- Stop, specifies how many packets below the start threshold are required to terminate a gap event.
The gap statistics are displayed on the “RECEIVE STATISTICS” panel, and gap events can be logged on the “RECEIVE LOG”.
You can enable a special payload checksum that covers all the bytes of the packet after the Ethernet header. With this, a payload error will be declared even for modifications inside the header, including time-to-live changes.
Some parts of the traffic generation uses pseudo-random values to vary the packet lengths, modifiers, etc. You can specify an explicit seed value that makes the values reproducible each time you start traffic generation, which can help debugging.