ltm rule command ROUTE rttvar
iRule(1) BIG-IP TMSH Manual iRule(1)
ROUTE::rttvar
Returns the cached round-trip-time variance (rttvar) estimate.
SYNOPSIS
ROUTE::rttvar DESTINATION_IP_ADDRESS (GATEWAY_IP_ADDRESS)?
DESCRIPTION
Returns the cached round-trip-time variance (rttvar) for the
destination and/or gateway if the relevant TCP profile enables
cmetrics-cache.
The return value only applies to the TMM executing the command. It does
not consider cache entries on other TMMs.
ROUTE::rttvar returns a value of 0 when there are no statistics
available.
NOTE: The returned value is scaled to units of 100ns; to express it in
the same units as TCP::rttvar multiply it by 16/10000.
NOTE: When used with the fastL4 profile, RTT from client/server needs
to be enabled and the client and server need to be using TCP
timestamps.
Syntax
ROUTE::rttvar
* The cached average variance in smoothed round-trip times for
connections to the given destination IP address.
ROUTE::rttvar
* The cached average variance in smoothed round-trip times for
connections to the given destination IP address reached through the
given gateway.
RETURN VALUE
VALID DURING
EXAMPLES
when CLIENT_ACCEPTED {
log local0. "Cached rttvar is: [ROUTE::rttvar [IP::remote_addr]]"
}
when CLIENT_ACCEPTED {
set Gateway 10.3.1.11
# assume that $Gateway is the gateway address for [IP::remote_addr]
log local0. "Cached rttvar is: [ROUTE::rttvar [IP::remote_addr] $Gateway]"
}
HINTS
SEE ALSO
CHANGE LOG
@BIGIP-9.0.0 --First introduced the command.
BIG-IP 2017-01-31 iRule(1)