An EX4300 device that is running Junos OS 17.3R3.10 or later has a 10G AE trunk with one IRB in it that is up and running. When a second IRB is added to the trunk and the changes are committed, everything works as expected. However, when a rollback is applied to remove the second IRB, the first IRB across the AE no longer works.
Note: This issue is observed in Junos OS 17.3R3.10 and later.
This article indicates the Junos OS release in which the fix is available, and gives a couple workarounds to use in the meantime to recover from the issue.
A lab reproduction of the problem is as follows:
The EX4300 interface configuration is as follows:
root@LAB-EX4300> show configuration | match "ae0|254" | display set set interfaces xe-0/2/0 ether-options 802.3ad ae0 set interfaces xe-0/2/1 ether-options 802.3ad ae0 set interfaces ae0 aggregated-ether-options minimum-links 1 set interfaces ae0 aggregated-ether-options link-speed 10g set interfaces ae0 aggregated-ether-options lacp active set interfaces ae0 unit 0 family ethernet-switching interface-mode trunk set interfaces ae0 unit 0 family ethernet-switching vlan members mgmt set interfaces ae0 unit 0 family ethernet-switching vlan members prod set interfaces irb unit 254 family inet address 10.10.254.2/24 set vlans mgmt vlan-id 254 set vlans mgmt l3-interface irb.254
The remote side configuration is as follows:
set interfaces xe-0/0/22 ether-options 802.3ad ae0 set interfaces xe-0/0/23 ether-options 802.3ad ae0 set interfaces ae0 aggregated-ether-options minimum-links 1 set interfaces ae0 aggregated-ether-options link-speed 10g set interfaces ae0 aggregated-ether-options lacp active set interfaces ae0 unit 0 family ethernet-switching interface-mode trunk set interfaces ae0 unit 0 family ethernet-switching vlan members mgmt set interfaces ae0 unit 0 family ethernet-switching vlan members prod set interfaces irb unit 254 family inet address 10.10.254.1/24 set vlans mgmt vlan-id 254 set vlans mgmt l3-interface irb.254
Connectivity is verified from EX4300 to the remote side. Note that connection is working properly.
root@LAB-EX4300# run ping 10.10.254.1 PING 10.10.254.1 (10.10.254.1): 56 data bytes 64 bytes from 10.10.254.1: icmp_seq=0 ttl=64 time=18.175 ms 64 bytes from 10.10.254.1: icmp_seq=1 ttl=64 time=12.156 ms 64 bytes from 10.10.254.1: icmp_seq=2 ttl=64 time=5.179 ms ^C --- 10.10.254.1 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 5.179/11.837/18.175/5.310 ms
Configuration is applied to the second IRB and the changes are committed. Note that connectivity is not impacted.
root@LAB-EX4300# load set terminal [Type ^D at a new line to end input] set vlans V666 vlan-id 666 set vlans V666 l3-interface irb.666 set interfaces irb.666 family inet address 15.15.15.2/30 set interfaces ae0 unit 0 family ethernet-switching vlan members V666 load complete {master:0}[edit] root@LAB-EX4300# show | compare [edit interfaces ae0 unit 0 family ethernet-switching vlan] - members [ mgmt prod ]; + members [ mgmt prod V666 ]; [edit interfaces irb] + unit 666 { + family inet { + address 15.15.15.2/30; + } + } [edit vlans] + V666 { + vlan-id 666; + l3-interface irb.666; + } {master:0}[edit] root@core-4300-VC# commit commit complete root@LAB-EX4300# run ping 10.10.254.1 PING 10.10.254.1 (10.10.254.1): 56 data bytes 64 bytes from 10.10.254.1: icmp_seq=0 ttl=64 time=7.623 ms 64 bytes from 10.10.254.1: icmp_seq=1 ttl=64 time=10.184 ms ^C --- 10.10.254.1 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max/stddev = 7.623/8.903/10.184/1.281 ms
When the configuration is rolled back, the first IRB no longer works.
root@LAB-EX4300# rollback 1 load complete {master:0}[edit] root@LAB-EX4300# show | compare [edit interfaces ae0 unit 0 family ethernet-switching vlan] - members [ mgmt prod V666 ]; + members [ mgmt prod ]; [edit interfaces irb] - unit 666 { - family inet { - address 15.15.15.2/30; - } - } [edit vlans] - V666 { - vlan-id 666; - l3-interface irb.666; - } {master:0}[edit] root@LAB-EX4300# commit commit complete {master:0}[edit] root@LAB-EX4300# run ping 10.10.254.1 PING 10.10.254.1 (10.10.254.1): 56 data bytes ^C --- 10.10.254.1 ping statistics --- 3 packets transmitted, 0 packets received, 100% packet loss {master:0}[edit] root@LAB-EX4300# run show interfaces ae0 terse Interface Admin Link Proto Local Remote ae0 up up ae0.0 up up eth-switch
The problem has been resolved in Junos OS release 17.3R4 and later.
Meanwhile, a couple of workarounds recover from this state are follows:
OR