Specifications

tunnel mpls traffic-eng auto-bw
MP-855
Cisco IOS Multiprotocol Label Switching Command Reference
January 2010
Usage Guidelines If you enter the command with no optional keywords or arguments, automatic bandwidth adjustment for
the tunnel is enabled, with adjustments made every 24 hours and with no constraints on the bandwidth
adjustment made.
To sample the bandwidth used by a tunnel without automatically adjusting it, specify the co
llect-bw
keyword in the tunnel mpls traffic-eng auto-bw command.
If you do not specify the co
llect-bw keyword, the tunnel’s bandwidth is adjusted to the largest average
output rate sampled for the tunnel since the last bandwidth adjustment for the tunnel was made. If you
do not specify the collect-bw keyword but you do enter some but not all of the other keywords, the
defaults for the options not entered are: frequency, every 24hours; min-bw, unconstrained (0); and
max-bw, unconstrained.
To constrain the bandwidth adjustment that can be made to a tunnel, use the max-
bw or min-bw keyword
and specify the permitted maximum allowable bandwidth or minimum allowable bandwidth,
respectively.
The following rules apply to adjusting bandwidth on a tunnel:
• If the current bandwidth is less than 50 kbps, you can change the bandwidth only if the changed
bandwidth is 10 kbps or more.
• If the current bandwidth is more than 50 kbps, you can change the bandwidth regardless of what
percent it is of the current bandwidth.
• If the minimum or maximum bandwidth values are configured for a tunnel, the bandwidth stays
between those values.
• If you configure a tunnel’s bandwidth (in the tunnel mpls traffic-eng bandwidth command) and
the minimum amount of automatic bandwidth (in the tunnel mpls traffic-eng auto-bw command),
the minimum amount of automatic bandwidth adjustment is the lower of those two configured
values. The default value of the tunnel mpls traffic-eng bandwidth command is 0.
The no f
orm of the tunnel mpls traffic-eng auto-bw command disables bandwidth adjustment for the
tunnel and restores the configured bandwidth for the tunnel bandwidth where “configured bandwidth”
is determined as follows:
• If the tunnel bandwidth was explicitly configured via the tunnel mpls traffic-eng bandwidth
command after the running configuration was written (if at all) to the startup configuration, the
“configured bandwidth” is the bandwidth specified by that command.
• Otherwise, the “configured bandwidth” is the bandwidth specified for the tunnel in the startup
configuration.
Note When you save the router configuration, the current bandwidth (not the originally configured bandwidth)
is saved for tunnels with automatic bandwidth enabled.
Note Each tunnel mpls traffic-eng auto-bw command supersedes the previous one. Therefore, if you want
to specify multiple arguments for a tunnel, you must specify them all in a single tunnel mpls traffic-eng
auto-bw command.
Note Keywords for the tunnel mpls traffic-eng auto-bw command are order-dependent; you must enter them
in the order in which they are listed in the command format.