# tcp path-mtu-discovery

#### Syntax

[ ip ] tcp path-mtu-discovery [ vrf vrfName ] [ age-timer [ indefinite | minutes
[ minutes_2 ] ] | max-mtu maxMtu | min-mtu minMtu | black-hole-detect-threshold blackHoleThreshold }

no [ ip ] tcp path-mtu-discovery [ vrf vrfName ] [ age-timer | max-mtu | min-mtu | black-hole-detect-threshold }

#### Release Information

Command introduced before JunosE Release 7.1.0.
ip keyword made optional in JunosE Release 7.2.0.

#### Description

Enables and configures path MTU discovery on the virtual router. Issuing the command without any keywords enables path MTU discovery. Using the keywords with the command configures specified values. The no version, when issued with a keyword, deletes the value. When issued without any keywords, the no version disables path MTU discovery on the virtual router.

#### Options

- ip—Optional keyword for use with older scripts
- vrfName—Name of the VRF; string of 1–32 alphanumeric characters
- indefinite—Disables aging functions. That is, TCP does not attempt to increase the path MTU; the path MTU decreases only in response to received ICMP Too Big messages.
- minutes—Time (in minutes) that TCP waits after receiving an ICMP Too Big message before attempting to increase the path MTU. The timer range is 1–30 minutes.
- minutes_2—Time (in minutes) that TCP waits after a successful path MTU increase before attempting to increase it again. The timer range is 1–30 minutes.
- maxMtu—Maximum MTU size that the virtual router can accept; number, in the range 68–65535; default value is no limit
- minMtu—Minimum MTU value that the virtual router can accept; number, in the range 68–65535; default value is no limit
- blackHoleThreshold—Black hole threshold value that you want all connections on this virtual router to use. The range is 0–65535.

#### Mode

Router Configuration