Known Limitations

Powering up and configuring data path of 400G-ZR and 400G-ZR-M optics is not instant and takes more time comparatively with other optics. So, user has to wait enough time before switching to new speed configuration. If user switches from one speed to other speed without waiting will lead to interface down. PR1635443

Packet Forward Engine restart trigger followed by graceful switchover is an unsupported feature. The target PFE could get stuck in TRANSITION_OFFLINE or READY state. The user must wait for the target PFE state to be ONLINE before issuing switchover request. PR1740391

On native CPTX product, we assign the lowest of all family MTUs on Junos OS Evolved interface and assign to the kernel interface as we do not have explicit IFF representation in Linux. This can result in unexpected kernel interface state in some scenarios. For example, If the lowest family MTU is on IPv4 on evo interface and it is < 1280, the kernel interface mtu is no longer IPv6-compatible as IPv6 has a minimum mtu requirement of 1280. So, kernel gets rid of all IPv6 addresses on the interface. Similarly, Linux has minimum MTU requirement of 68 for IPv4. There is no recovery from this situation even if the IPv4 MTU configuration is undone as there are no resulting IPv6 specific DDS events from this undo operation. The only way to recover from this situation is to delete interface and re-configure the interface with the valid MTU. This is a product limitation and hence whenever family MTU configurations are performed via CLI on native CPTX, the user is expected to understand the impact of the configuration on all the families present on the interface and configure MTU that suits all families. PR1747980

On native CPTX product, we assign the lowest of all family MTUs on evo interface and assign to the kernel interface as we do not have explicit IFF representation in Linux. This can resulted unexpected kernel interface state in some scenarios. For example, If the lowest family MTU is on IPv4 on Junos OS Evolved interface and it is < 1280, the kernel interface mtu is no longer IPv6-compatible as IPv6 has a minimum mtu requirement of 1280. So, kernel gets rid of all IPv6 addresses on the interface. There is no recovery from this situation even if the IPv4 MTU configuration is undone as there are no resulting IPv6 specific DDS events from this undo operation. The only way to recover from this situation is to delete interface and re-configure the interface with the valid MTU. This is a product limitation and hence whenever family MTU configurations are performed through CLI on native CPTX, the user is expected to understand the impact of the configuration on all the families present on the interface and configure MTU that suits all families.PR1746443

On native CPTX product, we assign the lowest of all family MTUs on evo interface and assign to the kernel interface as we do not have explicit IFF representation in Linux. This can resulted unexpected kernel interface state in some scenarios. For example, If the lowest family MTU is on IPv4 on Junos OS Evolved interface and it is < 1280, the kernel interface mtu is no longer IPv6-compatible as IPv6 has a minimum mtu requirement of 1280. So, kernel gets rid of all IPv6 addresses on the interface. There is no recovery from this situation even if the IPv4 MTU configuration is undone as there are no resulting IPv6 specific DDS events from this undo operation. Similarly Linux has minimum MTU requirement of 68 for IPv4. The only way to recover from this situation is to delete interface and re-configure the interface with the valid MTU. This is a product limitation and hence whenever family MTU configurations are performed through CLI on native CPTX, the user is expected to understand the impact of the configuration on all the families present on the interface and configure MTU that suits all families.PR1747705