Discussion

Solution
Add the new interface to the router configuration but keep it deactivated:
[edit interfaces]
aviva@router1# set ge-1/1/0 unit 0 family inet address 172.19.121.3/24
aviva@router1# set ge-1/1/0 description "172.19.121.3/24; to router2's ge-0/0/1"
aviva@router1# deactivate ge-1/1/0
Use the following command to activate the interface:
[edit interfaces]
aviva@router1# activate ge-1/1/0
Discussion
When you are preparing the router for new hardware, either a new PIC or a new FPC
with one or more PICs, or when you have a maintenance window in which you will
be rearranging the FPCs or PICs in the router, you can preconfigure the interfaces
before the hardware has arrived or is in the new location. This recipe shows how to
configure a Gigabit Ethernet interface before the PIC is in the router.
The management process, MGD, ignores all inactive portions of the configuration
when you issue a commit command. The deactivated configuration is effectively commented
out of the configuration file, and the interface control daemons will not see
the configuration data. One downside to this is that if there are mistakes in your configuration,
you won’t see the errors messages from MGD.
Because no physical hardware is installed in the router, you don’t see this interface
with any of the show interfaces commands. The only way to know that it’s there is
to look at the configuration. If you are outside the deactivated hierarchy, the CLI
marks it with the string inactive:
[edit interfaces]
aviva@router1# show
inactive: ge-1/1/0 {
description "172.19.121.3/24; to router2's ge-0/0/1";
unit 0 {
family inet {
address 172.19.121.3/24;
}
}
}
If you issue the show command from a hierarchy that is within the deactivated statement,
the CLI shows a three-line notice to catch your attention:
[edit interfaces]
aviva@router1# show ge-1/1/0
##
## inactive: interfaces ge-1/1/0
##
description "172.19.121.3/24; to router2's ge-0/0/1";
Configuring Interfaces Before the PICs Are Installed | 243
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