Skip to content
Zipline Zipline Service Documentation

    Check Link Layer

    published Last Updated: Oct 9, 2026 HW: all 
    Use the linux IP command
    

    

    UP/DOWN == the administrator has specified it is up
    LOWER_UP/LOWER_DOWN (NO ARP) == The status of the lower layers (Cable connected, wifi up, etc)
    

    

    Happy one:
    $ ip link show dev <interface>
    8: <interface>@end0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
        link/ether 82:86:08:1e:09:40 brd ff:ff:ff:ff:ff:ff
    $
    

    

    Disconnected one:
    $ ip link show dev <interface>
    8: <interface>@end0: <NO ARP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
        link/ether 82:86:08:1e:09:40 brd ff:ff:ff:ff:ff:ff
    $
    

    

    Sad one:
    $ ip link show dev <interface>
    8: <interface>@end0: <BROADCAST,MULTICAST,DOWN,LOWER_DOWN> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
        link/ether 82:86:08:1e:09:40 brd ff:ff:ff:ff:ff:ff

    Did this guide help you get unblocked?

    Open suggestions

    There are no open suggestions.

    Open pull requests

    There are no open pull requests.

    Edit this page on GitHub
    Topic history
    1. 2026-10-07 Susan Minne Bulk/mechanical change
      Replace individual guide ownership with system technical contacts
      Commit dca5a1a
    2. 2026-09-24 Susan Minne Bulk/mechanical change
      chore: backfill asset and dock owner identities
      Commit c82f87b
    3. 2026-09-23 Susan Minne Bulk/mechanical change
      docs: remove obsolete Confluence metadata
      Commit 2d5374e
    4. 2026-09-13 Susan Minne Bulk/mechanical change
      feat: add MX approval metadata to topics
      Commit 406a785
    Baseline import
    Initial import into service_docs
    Imported by Susan Minne on 2026-06-08
    Move migrated topics into correct sections
    Commit 599b402
    Suggest a change