Route Tag Structure; Setting Route Tags; Table 14: Configuration Tasks For Setting Is-Is Route Tags - Juniper IGP - CONFIGURATION GUIDE V11.1.X Configuration Manual

Route Tag Structure

On E Series routers, an IS-IS route tag is a 32-bit (4-octet) nonzero number that is
stored as sub-TLV 1 inside the extended IP reachability TLV (type 135). TLV type 135,
in turn, is part of an IS-IS LSP. The route tag is therefore advertised when LSPs are
transmitted in an IS-IS network.
Because TLV type 135 is a new-style TLV tuple, it has a data structure that includes
a wide metric field of four octets. As a result, to use IS-IS route tags you must issue
the metric-style wide command (in Router Configuration mode) to specify that the
router generate and accept only new-style TLV tuples.
For a discussion of IS-IS support for TLV tuples, see "Extensions for Traffic
Engineering" on page 333.

Setting Route Tags

You can set IS-IS route tags in any of the following ways:
Tagging a route for IP addresses on an IS-IS passive interface
Tagging a route for IP addresses on an IS-IS interface
Tagging IS-IS routes by using an associated route map to set the tag
Tagging an IS-IS summary address
For instructions and examples on configuring IS-IS route tags, see the sections listed
in Table 14 on page 335.

Table 14: Configuration Tasks for Setting IS-IS Route Tags

To Learn About
Setting a route tag for an IS-IS passive
interface
Setting a route tag for an IS-IS
interface
Setting a route tag for a route
redistributed from another protocol
to IS-IS by using an associated route
map
Setting a route tag for a route
redistributed from one IS-IS level to
another IS-IS level by using an
associated route map
Setting a route tag for an IS-IS default
route by using an associated route
map
Using This Command See
"passive-interface" on "Configuring Passive
page 352 Interfaces" on page 352
"isis tag" on page 355 "Configuring Route Tags for
IS-IS Interfaces" on page 354
"redistribute" on "Configuring Redistribution"
page 361 on page 359
"redistribute isis ip" on "Redistributing Routes
page 363 Between Levels" on page 362
"default-information "Configuring Default Routes"
originate" on page 367 on page 367
Chapter 6: Configuring IS-IS
335
Overview