OcNOS-RON : Layer 3 Guide : Intermediate System to Intermediate System Command Reference : IS-IS Show Commands : show ip isis route
show ip isis route
Use this command to display IS-IS routing table for IPv4.
Command Syntax
show ip isis (WORD|) route
Parameters
WORD
Information for a single IS-IS area.
Command Mode
Exec mode, Privileged exec mode
Applicability
This command was introduced before OcNOS version 1.3.
Example
#show ip isis route
Codes: C - connected, E - external, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, D - discard, e - external metric
Tag xyz: VRF : default
Destination Metric Next-Hop Interface Tag
L1 10.10.10.0/24 20 11.11.11.1 eth1 0
C 11.11.11.0/24 10 – eth1 0
#
Header
Each entry in this table has a code preceding it, indicating the source of the routing entry. Table 3-75 shows these codes.
Table 3-75 explains the fields in the output.
 
Table 3-75: route codes and modifiers 
Code
Description
C
Routes directly connected to the local device that were not distributed via IGP. The device inherently knows of these networks, so there is no need to learn about these from another device.
Connected routes are preferred over routes for the same network learned from other routing protocols.
E
External.
L1
IS-IS level-1.
L2
IS-IS level-2.
ia
IS-IS inter area (leaked).
D
Discard route. A device performing summarization installs a discard route in its routing table for the summarized network range to prevent routing loops where portions of the summarized network range do not have a more specific route in the RIB.
External and internal discard route entries are installed by default. During route summarization, routing loops can happen if data sent to a nonexisting network appears to be a part of the summary, and the router doing the summarization has a less specific route that points back to the sending router for the network.
e
External metric. Routes can be redistributed into IS-IS with either internal or external metrics (internal is the default). The metric type determines the base metric value of the redistributed routes. The value of an internal metric is lower than 64. The value of an external metric is 64-128.
Route Entry Fields
Table 3-76 shows the route entry fields.
 
Table 3-76: route entry fields
Field
Description
Code
As explained in Table 3-75.
Tag
Name that identifies the IS-IS area.
VRF
VRF name.
Destination
IP address of the remote network.
Metric
ISIS metric used for SPF calculation (1-63).
When a route is imported into the IS-IS network without a specified metric, IS-IS uses 10 for the metric value and the value is applied to both level-1 and level-2.
Next-Hop
This route is available through the next hop router located at this IP address. This identifies exactly where packets go when they match this route.
Interface
Interface used to get to the next-hop address for this route.
Tag
Name that identifies the IS-IS area.
Last modified date: 08/28/2023