This article explain the meaning of "mac_local_fault:1 mac_remote_fault: 0 asic_fault: 0"
In this case, customer is having two juniper device connected via some transport L2 network.
Transport network
Device-A | Rx <--------------- Tx | Device-B | Tx ---------------> Rx |
Device-A port et-7/1/14 flapping and setting the “mac_local_fault:1” alarm. A local fault is usually caused by a lack of light being received or out of normal\good range from nearby equipment.
At this point, Device-A interface can no longer receive data on this link. However, it may still be able to transmit data over the link, as the PHY layer’s transmitter may still be functional. It’s good that Device-A find a way to inform Device-B that it is no longer receiving valid data from Device-B so that Device-B does not recklessly continue to send data across the link that will never be received by Device-A.
This is where the Remote Fault comes into play. Device-A will send Remote-Fault-Notifications (RFNs) to remote end Device-B and the Device-B will be reporting "mac_remote_fault:1".
Device-B will generally declare the interface as “down”, allowing higher-level protocols to take appropriate action (such as routing protocols reconverging, etc.) So that it does not black hole traffic towards Device-A.
[Aug 25 03:12:18.135 LOG: Warning] T6E(7/1) link[14 0] DOWN, phy_link_ok: 0 mac_local_fault:1 mac_remote_fault: 0 asic_fault: 0
[Aug 25 03:12:18.135 LOG: Info] ifp et-7/1/14 ifd_mdown: 44382621318 ms
[Aug 25 03:12:18.136 LOG: Info] prds_if_ifd_stream_disable: Disbaled OQ to EPRQ mapping oq = 424 eprq = 0 chip = 5 enbl flag = Disabled
[Aug 25 03:12:18.136 LOG: Info] prds_if_ifd_stream_disable: Disbaled OQ to EPRQ mapping oq = 425 eprq = 0 chip = 5 enbl flag = Disabled
[Aug 25 03:12:18.136 LOG: Info] prds_if_ifd_stream_disable(et-7/1/14, 5, 0, 1): mac_cmd:628953, mstrm:0
[Aug 25 03:12:19.186 LOG: Warning] T6E(7/1) link[14 0] UP, phy_link_ok: 1 mac_local_fault:0 mac_remote_fault: 0 asic_fault: 0
Check the KB https://supportportal.juniper.net/s/article/Troubleshooting-Checklist-Ethernet-Physical-Interfaces for detailed troubleshooting and solution.