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Known Limitations

Learn about known limitations in Junos OS Release 21.4R2 for SRX Series Gateways.

For the most complete and latest information about known Junos OS defects, use the Juniper Networks online Junos Problem Report Search application.

Flow-Based and Packet-Based Processing

  • Use an antireplay window size of 512 for IPv4 or IPv6 in fat-tunnel. The ESP sequence check might otherwise report out-of-order packets if the fat-tunnel parallel encryption is within 384 packets (12 cores * 32 packets in one batch). Hence, there are no out-of-order packets with 512 antireplay window size. PR1470637


  • The Firefox browser displays an unsaved changes error message in the J-Web Basic Settings page if the Autofill logins and passwords option is selected under the Browser Privacy and security settings. PR1560549

Platform and Infrastructure

  • SRX Series devices might encounter ISSU aborted with error "ISSU is not supported for Clock Synchronization (SyncE)" during upgrades from any release prior to Junos OS release 22.1 to 22.1 or above releases. PR1632810


  • In some scenario (for example, configuring firewall filter), routers might show obsolete IPsec SA and NHTB entry even when the peer tear down the tunnel. PR1432925

  • An IPsec policy must not have both ESP and AH proposals. The configuration will commit, but the IPsec traffic will not work. Do not configure an IPsec policy with proposals using both ESP and AH protocols. PR1552701