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Changes in Behavior and Syntax in QFX5110 and QFX5200 Switches


This section lists the changes in behavior of Junos OS features and changes in the syntax of Junos OS statements and commands for Junos OS Release 15.1X53 for QFX5110 and QFX5200 switches.

Authentication and Access Control

  • Change in default value for port ID TLV for QFX5200 switches—Starting from Junos OS Release 15.1X53-D230, for QFX5200 switches, the default value used for port ID TLV in LLDP messages is interface name, not SNMP index.


  • When the no-propagate-ttl statement is configured on a QFX5200 switch in an MPLS network, the TTL value is not copied and decremented on the transit devices during a swap operation. When the switch acts as an ingress device for an LSP, it pushes an MPLS header with a TTL value of 255, regardless of the IP packet TTL. When the switch acts as the penultimate provider switch, it pops the MPLS header without writing the MPLS TTL into the IP packet.


  • Syslog or log action on firewall drops packets (QFX5110 and QFX5200 switches)—Starting in 15.1X53-D236, if you configure a syslog or log action on an ingress firewall filter, control packets and ICMP packets sent to the Routing Engine might be dropped.