Administrator Guide

Changing the IS-Type
To change the IS-type, use the following commands.
You can configure the system to act as a Level 1 router, a Level 1-2 router, or a Level 2 router.
To change the IS-type for the router, use the following commands.
● Configure IS-IS operating level for a router.
ROUTER ISIS mode
is-type {level-1 | level-1-2 | level-2-only}
Default is level-1-2.
● Change the IS-type for the IS-IS process.
ROUTER ISIS mode
is-type {level-1 | level-1-2 | level-2}
To view which IS-type is configured, use the show isis protocol command in EXEC Privilege mode. The show config
command in ROUTER ISIS mode displays only non-default information, so if you do not change the IS-type, the default value
(level-1-2) is not displayed.
The default is Level 1-2 router. When the IS-type is Level 1-2, the software maintains two Link State databases, one for each
level. To view the Link State databases, use the show isis database command.
Dell#show isis database
IS-IS Level-1 Link State Database
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
B233.00-00 0x00000003 0x07BF 1088 0/0/0
eljefe.00-00 * 0x00000009 0xF76A 1126 0/0/0
eljefe.01-00 * 0x00000001 0x68DF 1122 0/0/0
eljefe.02-00 * 0x00000001 0x2E7F 1113 0/0/0
Force10.00-00 0x00000002 0xD1A7 1102 0/0/0
IS-IS Level-2 Link State Database
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
B233.00-00 0x00000006 0xC38A 1124 0/0/0
eljefe.00-00 * 0x0000000D 0x51C6 1129 0/0/0
eljefe.01-00 * 0x00000001 0x68DF 1122 0/0/0
eljefe.02-00 * 0x00000001 0x2E7F 1113 0/0/0
Force10.00-00 0x00000004 0xCDA9 1107 0/0/0
Dell#
Controlling Routing Updates
To control the source of IS-IS route information, use the following command.
● Disable a specific interface from sending or receiving IS-IS routing information.
ROUTER ISIS mode
passive-interface interface
○ For a 1-Gigabit Ethernet interface, enter the keyword GigabitEthernet then the slot/port information.
○ For the Loopback interface on the RPM, enter the keyword loopback then a number from 0 to 16383.
○ For a port channel, enter the keywords port-channel then a number.
○ For a SONET interface, enter the keyword sonet then the slot/port information.
○ For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/ port information.
○ For a VLAN, enter the keyword vlan then a number from 1 to 4094.
Distribute Routes
Another method of controlling routing information is to filter the information through a prefix list.
Prefix lists are applied to incoming or outgoing routes and routes must meet the conditions of the prefix lists or the system does
not install the route in the routing table. The prefix lists are globally applied on all interfaces running IS-IS.
Intermediate System to Intermediate System
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