This article explains the different fabric states that can be encountered on MX platforms.
The MX software maintains states at two levels of the fabric components; planes and links.
A fabric plane can be in any one of the following states:
- Online: A fabric plane with all of its links are error free and enabled, ready for carrying data traffic.
- Spare: A fabric plane with all of its links are error free, in a standby mode, ready to be enabled
- Offline: A fabric plane with all of its links in an un-trained state. This state can be a result of user requested operation, or can be triggered by fatal error(s) detected by the system.
- Check: A fabric plane with one or more of its link(s) or destination(s) has errors.
- Empty: A fabric plane whose hardware does not exist in the chassis.
A fabric link can be in any one of the following states:
- Unused: A fabric is in an un-trained, un-used mode.
- OK: A fabric is trained, error-free, ready to be enabled.
- Enabled: A fabric link is error free and currently enabled.
- Disabled: A fabric link is disabled. This can be a result of user operation, or done by the system due to link error.
- Error: Fabric error(s) has been detected on the link, or the link training has failed.
- Enable Error: Error happened during the link enable/disable operation.
- Dest Error: Destination error is detected on this link, but can be caused by remote side links.
Following command provides related information :
root@rtr> show chassis fabric legend
Legend for show chassis fabric state:
Unused:
The link is not trained and is disabled.
Links ok:
The link is in error-free condition and carries traffic only if it belongs to an online plane.
Link error:
The link encounters CRC errors and carries traffic only if it belongs to an online plane.
Link error: (TF)
The link encounters training error and is disabled.
Destination error:
The FPC has reported destination errors on the link and the link is disabled.
Plane disabled:
The link is disabled due to error or plane is offlined.
Plane enabled:
The link is enabled and carries traffic.
Plane enable error:
The link encounters ASIC error and is disabled.
Note 1: (TF)
When present, indicates training failure.
Note 2: Plane link state
Plane link state (show chassis fabric plane) only tracks whether a link is trained or not, therefore possible plane link states are: Unused, Links ok, Link error (for CRC or TF).
Note 3: Plane Online/Spare state
A link may carry traffic only if it is from an online plane.
Refer to show chassis fabric summary [extended] for Online/Spare plane state.
root@rtr> show chassis fabric summary extended <-- "extended" option is available from Junos release 14.1R2
Plane State Link Link Destination errors Uptime
Error TF Local / Remote
0 Online NO NO NO/ NO 1 day, 14 hours, 45 minutes, 34 seconds
1 Online NO NO NO/ NO 1 day, 14 hours, 45 minutes, 34 seconds
2 Online NO NO NO/ NO 1 day, 14 hours, 45 minutes, 34 seconds
3 Online NO NO NO/ NO 1 day, 14 hours, 45 minutes, 33 seconds
4 Online NO NO NO/ NO 1 day, 14 hours, 45 minutes, 33 seconds
5 Online NO NO NO/ NO 1 day, 14 hours, 45 minutes, 33 seconds
Additional commands useful for fabric troubleshooting:
show chassis fabric destinations
show chassis fabric fpcs
show chassis fabric map
show chassis fabric plane
show chassis fabric reachability
show chassis fabric redundancy-mode