Reference Guide

Intermediate System to Intermediate System | 435
Figure 20-6. Command Example: show running-config isis
Configure IS-IS metric style and cost
All IS-IS links or interfaces are associated with a cost that is used in the SPF calculations. The possible
cost varies depending on the metric style supported. If you configure narrow, transition or narrow
transition metric style, the cost can be a number between 0 and 63. If you configure wide or wide transition
metric style, the cost can be a number between 0 and 16,777,215. FTOS supports five different metric
styles: narrow, wide, transition, narrow transition, and wide transition.
By default, FTOS generates and receives narrow metric values. Metrics 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 metric is configured as narrow, and an LSP with wide metrics is received, the
route is not installed.
FTOS supports the following IS-IS metric styles:
Use the following command in ROUTER ISIS mode to change the IS-IS metric style of the IS-IS process.
Use the
show isis protocol command (Figure 476) in EXEC Privilege mode to view which metric types are
generated and received.
Table 20-2. 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
Command Syntax Command Mode Purpose
metric-style {narrow [transition] |
transition | wide [transition]} [level-1 |
level-2]
ROUTER ISIS Set the metric style for the IS-IS process.
Default: narrow
Default: Level 1 and Level 2 (level-1-2)
FTOS#show running-config isis
!
router isis
lsp-refresh-interval 902
net 47.0005.0001.000C.000A.4321.00
net 51.0005.0001.000C.000A.4321.00
FTOS#