This article explains a software bug where with addition of IPv6 filter to DSC interface, AFTMAND crash is seen and this crash leads to router reboot.
AFTMAND crash and router reboot.
root@e08-45> show system core-dumps
error: the command-handler subsystem is not responding to management requests
-rw------- 1 root root 1835008 Jul 1 03:05 /var/core/re0/evo-aftmand-bt.re.re0.22466.2024_07_01.03_03_28.tar.gz
This is due to a software bug.
https://prsearch.juniper.net/problemreport/PR1820118
The DSC interface feature requires DLU action word to set implicit filter in the lookup entry. The default size for IPv6 prefix length <= 88 is single wide. The single-wide entry does not have enough space for DLU action and NH. It would cause crash in NH code.
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Replication Steps
AFTMAN crash is seen with addition of just IPv6 filters on DSC interface:
labroot@e08-45# show |compare
Jul 01 03:03:25
[edit interfaces dsc unit 0 family inet6]
+ filter {
+ output IPV6-GANDALF-DISCARD;
+ }
[edit]
labroot@e08-45# commit and-quit
Jul 01 03:03:26
--------------
Work-around
AFTMAN crash is not seen when we add DSC config without IPv6 filter:
root@e08-45# show |compare
[edit interfaces]
+ dsc {
+ unit 0 {
+ family inet {
+ output IPV4-GANDALF-DISCARD;
+ address 192.0.0.5/32 {
+ destination 192.0.0.6;
+ family inet6 {
+ address 100::5/128 {
+ destination 100::6;
root@e08-45#
root@e08-45> show system uptime
Jul 01 03:10:53
Current time: 2024-07-01 03:10:53 UTC
Time Source: LOCAL CLOCK
Node booted: 2024-07-01 03:04:52 UTC (00:06:01 ago)
System booted: 2024-07-01 03:04:52 UTC (00:06:01 ago)