When the platform has graceful Routing Engine switchover (GRES) configured and performs either GRES switchover or acquires the primary role from the backup Routing Engine, this action has an implication on the Switch Interface Boards (SIBs) that are installed.

This article clarifies that the behavior is as per system design and that no traffic impact is expected.

Note: The issue is tracked in PR1568259 .

For example

{BACKUP}
user@PTX10016> request chassis routing-engine master acquire
Attempt to become the master routing engine ? [yes,no] (no) yes

This is seen in syslog:

<28>1 2021-01-05T07:32:00.358Z PTX10016>alarmd 24751 - - Alarm set: SIB color=YELLOW, class=CHASSIS, reason=SIB 0 Not Online
<28>1 2021-01-05T07:32:00.358Z PTX10016>craftd 14673 - -  Minor alarm set, SIB 0 Not Online
<28>1 2021-01-05T07:32:00.368Z PTX10016>alarmd 24751 - - Alarm set: SIB color=YELLOW, class=CHASSIS, reason=SIB 1 Not Online
<28>1 2021-01-05T07:32:00.368Z PTX10016>craftd 14673 - -  Minor alarm set, SIB 1 Not Online
<28>1 2021-01-05T07:32:00.371Z PTX10016 alarmd 24751 - - Alarm set: SIB color=YELLOW, class=CHASSIS, reason=SIB 2 Not Online
<28>1 2021-01-05T07:32:00.371Z PTX10016 craftd 14673 - -  Minor alarm set, SIB 2 Not Online
<28>1 2021-01-05T07:32:00.371Z PTX10016 alarmd 24751 - - Alarm set: SIB color=YELLOW, class=CHASSIS, reason=SIB 3 Not Online
<28>1 2021-01-05T07:32:00.371Z PTX10016 craftd 14673 - -  Minor alarm set, SIB 3 Not Online
<28>1 2021-01-05T07:32:00.371Z PTX10016 alarmd 24751 - - Alarm set: SIB color=YELLOW, class=CHASSIS, reason=SIB 4 Not Online
<28>1 2021-01-05T07:32:00.371Z PTX10016 craftd 14673 - -  Minor alarm set, SIB 4 Not Online
<28>1 2021-01-05T07:32:00.371Z PTX10016 alarmd 24751 - - Alarm set: SIB color=YELLOW, class=CHASSIS, reason=SIB 5 Not Online
<28>1 2021-01-05T07:32:00.372Z PTX10016 craftd 14673 - -  Minor alarm set, SIB 5 Not Online

The following change of uptime is due to a soft refresh, not a hard reset:

lab@PTX10016> show chassis sibs detail | match up
Uptime                              1 hours, 19 minutes, 26 seconds
Uptime                              1 hours, 18 minutes, 37 seconds
Uptime                              1 hours, 17 minutes, 58 seconds
Uptime                              1 hours, 17 minutes, 21 seconds
Uptime                              1 hours, 16 minutes, 40 seconds
Uptime                              1 hours, 15 minutes, 58 seconds

On the new primary, the spmb process will perform a soft reset (initialization) of the SIBs/SFBs and the SIBs/SFBs state will get refreshed. The soft reset does NOT cause any functionality impact and it is expected behavior as part of system design. No traffic impact is expected. The issue is tracked in PR1568259 .

An example of PTX10016 SIBs:

SIB 0            REV 04   750-077140   AAAA1111          Switch Fabric 16
SIB 1            REV 04   750-077140   AAAA1112          Switch Fabric 16