Users Guide

new IPv6 protocol identifier has also been included in the supported TLVs. The new TLVs use the extended
metrics and up/down bit semantics.
Multi-topology IS-IS adds TLVs:
• MT TLV — contains one or more Multi-Topology IDs in which the router participates. This TLV is
included in IIH and the first fragment of an LSP.
• MT Intermediate Systems TLV — appears for every topology a node supports. An MT ID is added to the
extended IS reachability TLV type 22.
• MT Reachable IPv4 Prefixes TLV — appears for each IPv4 an IS announces for a given MT ID. Its
structure is aligned with the extended IS Reachability TLV Type 236 and it adds an MT ID.
• MT Reachable IPv6 Prefixes TLV — appears for each IPv6 an IS announces for a given MT ID. Its
structure is aligned with the extended IS Reachability TLV Type 236 and add an MT ID.
By default, the system supports dynamic host name exchange to assist with troubleshooting and
configuration. By assigning a name to an IS-IS NET address, you can track IS-IS information on that address
easier. The system does not support ISO CLNS routing; however, the ISO NET format is supported for
addressing.
To support IPv6, the Dell Networking implementation of IS-IS performs the following tasks:
• Advertises IPv6 information in the PDUs.
• Processes IPv6 information received in the PDUs.
• Computes routes to IPv6 destinations.
• Downloads IPv6 routes to the RTM for installing in the FIB.
• Accepts external IPv6 information and advertises this information in the PDUs.
The following table lists the default IS-IS values.
Table 39. IS-IS Default Values
IS-IS Parameter Default Value
Complete sequence number PDU (CSNP) interval 10 seconds
IS-to-IS hello PDU interval 10 seconds
IS-IS interface metric 10
Metric style Narrow
Designated Router priority 64
Circuit Type Level 1 and Level 2
IS Type Level 1 and Level 2
Equal Cost Multi Paths 16
Configuration Information
To use IS-IS, you must configure and enable IS-IS in two or three modes: CONFIGURATION ROUTER ISIS,
CONFIGURATION INTERFACE, and ( when configuring for IPv6) ADDRESS-FAMILY mode. Commands in
ROUTER ISIS mode configure IS-IS globally, while commands executed in INTERFACE mode enable and
configure IS-IS features on that interface only. Commands in the ADDRESS-FAMILY mode are specific to IPv6.
Intermediate System to Intermediate System 586