Using JWEB to configure the interface description on an EX Switch can cause a link fluctuation or interface down condition.  This happens because JWEB adds other link options when the description is added or changed.  The issue is fixed in later releases (above 9.2R3) as described in the Solution section.

Using JWEB to configure the interface description on an EX Switch can cause a link fluctuation or interface down condition.  This problem does not happen when configuring the interface description via CLI.

This is a known issue that is resolved in PR 389609.   The fix is to only send the port description change and not the other link options.  The fix is included in the following releases:

• 9.2R3 and above

There are two ways of setting up description on the interface in EX switches

1. CLI
2. JWEB

CLI commands:

juniper# set interfaces ge-0/0/4 description "Test description"
juniper# commit

JWEB procedure:

1. Login to JWEB by supplying username and password
2. Click on configure button on top
3. Select the interface to set up description
4. Click on " EDIT " button and Select " Link Options "
5. Add the interface description in field " Description " and click on OK button

The above procedure will add the description for the interface but will also add following additional configuration to the interface selected

mtu 1514;
ether-options {
    auto-negotiation;
    no-flow-control;
    link-mode automatic;
    speed {
        auto-negotiation;
    }
}

NOTE: This issue is fixed in any release above 9.2R3