light
Junos OS Syntax
light {
port number;
}
Junos OS Evolved Syntax
light {
offload-type (none | inline-timestamp | pfe-timestamp);
port number;
stateful-sequence cache-size size;
}
Junos OS Hierarchy Level
[edit services rpm twamp server]
Description
Enable the Two-Way Active Measurement Protocol (TWAMP) server for light control on
the UDP port that reflects the test packets. If you want the default IANA port for
TWAMP (862), you do not need to configure the port option. To complete the
configuration for light control, you also need to configure the control-type
light statement at either the Junos OS [edit services rpm twamp
client control-connection control-connection-name]
hierarchy level or the Junos OS Evolved [edit services monitoring twamp
client control-connection control-connection-name]
hierarchy level.
You configure the light statement because you want a stateless version of TWAMP where
test parameters are predefined instead of negotiated. All test packets received by
the server on a test port are reflected back and forgotten right away. If you want
to have a stateful TWAMP server for Junos OS Evolved, you should configure the
managed statement at the [edit services monitoring twamp
server] hierarchy level instead. For Junos OS, if you want to have a stateful TWAMP
server, do not configure the light statement for the TWAMP server,
because managed mode is the default. Because TWAMP light servers are stateless,
information about them is not included in the output of the show services
rpm twamp server connection (Junos OS) or the show services
monitoring twamp server control-info (Junos OS Evolved) operational
mode command; only information about managed servers is included.
Options
| offload-type (none | inline-timestamp | pfe-timestamp) |
Enable timestamping of TWAMP probe messages in the Routing Engine, inline
in the hardware, or Packet Forwarding Engine host processor. Prior to
Junos OS Evolved 22.3R1, for IPv6 traffic, you must configure
|
| port number |
Specify the UDP port that reflects the TWAMP test packets.
|
| stateful-sequence cache-size number-of-entries |
Configure stateful sequencing to generate the sequence number in the reflected payload independently, instead of copying the sequence number from the client frame. With independently generated sequence numbers, the software is able to detect in which direction drops have occurred. Unidirectional drop values are inferred minimum values, and are not guaranteed to be exact. The software relies on an actual packet to be reflected successfully to be able to compute differences. If such a packet does not occur, then the software is unable to tell whether the drop happened in the egress or ingress direction. Because TWAMP light (just like STAMP) is by nature stateless, stateful sequencing can only be done using a cache system. Currently, the software uses a FIFO system to manage the cache; the entry without an update for the longest time is the first one out to make space for a new entry.
|
Required Privilege Level
system—To view this statement in the configuration.
system-control—To add this statement to the configuration.
Release Information
Statement introduced in Junos OS Evolved 20.3R1.
Support added in Junos OS Release 21.1R1.
offload-type and stateful-sequence options
introduced in Junos OS Evolved Release 23.4R1.