Viewing cached destination information

View the destination cache to see next-hop addresses for destinations.

The destination cache is only populated or updated when IPv6 packets are locally originated on the central processor of the switch.

The main purpose of the destination cache is to store, on a per-destination basis, the dynamic Path MTU value currently used when transmitting packets from the local system to the remote destination. The PMTU value itself is used to calculate how many bytes can fit into an individual packet before fragmentation should be applied.

Before you begin

Change the VRF instance as required to view cached destination information on a specific VRF instance. Not all parameters are configurable on non-default VRFs.

Procedure

  1. In the navigation tree, expand the following folders: Configuration > IPv6.
  2. Click IPv6.
  3. Click the Destination Cache tab.

Destination Cache Field Descriptions

Use the data in the following table to use the Destination Cache tab.

Name

Description

DestAddr

Shows the IPv6 destination address.

Interface

Shows the interface number that is used to reach the destination.

NextHop

Shows the IPv6 address for the next hop to the destination.

IfType

Specifies the interface type (tunel, VLAN, or brouter) or virtual circuit (VRRP, RSMLT).

IfData

Displays additional information about virtual circuits. For instance, for a VRRP or RSMLT the virtual router ID displays. If the interface type is tunnel, VLAN, or brouter, no additional information displays.

Pmtu

Shows the path maximum transmission unit (MTU) for the destination.

PmtuAge

Shows the time, in seconds, since an ICMPv6 packet too big message was received.