Command Reference Guide

3Com Router 3000 Ethernet Family
Command Reference Guide
Chapter 6 IP Routing Policy Configuration
Commands
3Com Corporation
6-7
View
Routing policy view
Parameter
value: Specifies the tag value of route information.
Description
Use the apply tag command to set the tag area of OSPF route information.
Use the undo apply tag command to cancel the apply clause.
When a route is redistributed from protocol A to protocol B, and is redistributed back to
protocol A on some other routers, protocol A allows the tag field of the routing protocol
update packet to be transferred to the peer, that is, the information in the tag field can
traverse from protocol A to protocol B and then back to protocol A, without being lost.
OSPF, RIP2, ISIS, and BGP support the tag field, but RIP1 does not.
For example, when a BGP route is redistributed into OSPF and then redistributed back
to BGP on another router, the as-path attribute of the BGP route is lost. You can the
aplly tag command to set the OSPF tag field as as-path to guarantee the integrity of
the as-path attribute.
Related command: if-match interface, if-match acl, if-match ip-prefix, if-match ip
next-hop, if-match cost, if-match tag, route-policy, apply ip-address, apply
local-preference, apply cost, and apply origin.
Example
# Display how to define one apply clause. When it is used for setting route information
attribute, it sets the tag area of route information as 100.
[3Com -route-policy] apply tag 100
6.1.10 display ip ip-prefix
Syntax
display ip ip-prefix [ ip-prefix-name ]
View
Any view
Parameter
ip-prefix-name: Specifies displayed address prefix list name.
Description
Use the display ip ip-prefix command to view the address prefix list.