Concept Guide

Conguring the IS-IS Metric Style
All IS-IS links or interfaces are associated with a cost that is used in the shortest path rst (SPF) calculations. The possible cost varies
depending on the metric style supported.
If you congure narrow, transition, or narrow transition metric style, the cost can be a number between 0 and 63. If you congure wide or
wide transition metric style, the cost can be a number between 0 and 16,777,215. The system supports ve dierent metric styles: narrow,
wide, transition, narrow transition, and wide transition.
By default, the system generates and receives narrow metric values. Matrixes or costs higher than 63 are not supported. To accept or
generate routes with a higher metric, you must change the metric style of the IS-IS process. For example, if you congure the metric as
narrow, and a link state PDU (LSP) with wide metrics is received, the route is not installed.
The system supports the following IS-IS metric styles.
Table 42. Metric Styles
Metric Style Characteristics Cost Range Supported on IS-IS Interfaces
narrow Sends and accepts narrow or old TLVs
(Type, Length, Value).
0 to 63
wide Sends and accepts wide or new TLVs. 0 to 16777215
transition Sends both wide (new) and narrow (old)
TLVs.
0 to 63
narrow transition Sends narrow (old) TLVs and accepts both
narrow (old) and wide (new) TLVs.
0 to 63
wide transition Sends wide (new) TLVs and accepts both
narrow (old) and wide (new) TLVs.
0 to 16777215
To change the IS-IS metric style of the IS-IS process, use the following command.
• Set the metric style for the IS-IS process.
ROUTER ISIS mode
metric-style {narrow [transition] | transition | wide [transition]} [level-1 | level-2]
The default is narrow.
The default is Level 1 and Level 2 (level-1–2)
To view which metric types are generated and received, use the show isis protocol command in EXEC Privilege mode. The IS-IS
matrixes settings are in bold.
Example of Viewing IS-IS Metric Types
Dell#show isis protocol
IS-IS Router: <Null Tag>
System Id: EEEE.EEEE.EEEE IS-Type: level-1-2
Manual area address(es):
47.0004.004d.0001
Routing for area address(es):
21.2223.2425.2627.2829.3031.3233
47.0004.004d.0001
Interfaces supported by IS-IS:
Vlan 2
GigabitEthernet 4/22
Loopback 0
Redistributing:
532
Intermediate System to Intermediate System