On SRX4600 devices, a rare issue can occur during heavy traffic conditions where the FPGA may cause high-priority traffic queues to get stuck, resulting in packet drops. This can happen even with the default CoS configuration.

• Packet loss observed on interfaces.
• Issue persists even after replacing optics and cables.
• Some traffic queues become stuck and stop forwarding traffic.
• Network traffic may experience intermittent connectivity or degradation.

Applicable Conditions:

• Platform: SRX4600
• Heavy traffic processing

Workaround: Configure a static ARP entry to maintain reachability to the remote node:

# set interfaces <x-x/x/x> unit 0 family inet address <ip-address>/24 arp <ip-address> mac <mac-address>

Permanent Fix: This issue has been resolved under PR1823577. Upgrade to a Juniper software release that includes the fix for this PR.