Navigation  Back up to About Overview 
[+] Expand All
[-] Collapse All

No index entries found.

Changes in Default Behavior and Syntax in Junos OS Release 12.3 for ACX Series Routers

Interfaces and Chassis

  • Connectivity fault management MEPs on Layer 2 circuits and Layer 2 VPNs—On interfaces configured on ACX Series routers, you no longer need to configure the no-control-word statement at either the [edit protocols l2circuit neighbor neighbor-id interface interface-name] or the [edit routing-instances routing-instance-name protocols l2vpn] hierarchy level for Layer 2 circuits and Layer 2 VPNs over which you are running CFM maintenance endpoints (MEPs). This configuration is not needed because ACX Series routers support the control word for CFM MEPs. The control word is enabled by default.

    [ACX Series Universal Access Router Configuration Guide]


  • Change in automatically generated virtual-link-local-address for VRRP over IPv6— The seventh byte in the automatically generated virtual-link-local-address for VRRP over IPv6 is 0x02. This change makes the VRRP over IPv6 feature in the Junos OS 12.2R5, 12.3R3, 13.1R3, and later releases, inoperable with Junos OS 12.2R1, 12.2 R2, 12.2 R3, 12.2R4, 12.3R1, 12.3R2, 13.1R1, and 13.3R2 releases if automatically generated virtual-link-local-address ID used. As a workaround, use a manually configured virtual-link-local-address instead of an automatically generated virtual-link-local-address.

Junos OS XML API and Scripting

  • IPv6 address text representation is stored internally and displayed in command output using lowercase—Starting with Junos OS Release 11.1R1, IPv6 addresses are stored internally and displayed in the command output using lowercase. Scripts that match on an uppercase text representation of IPv6 addresses should be adjusted to either match on lowercase or perform case-insensitive matches.
  • <get-configuration> RPC with inherit="inherit" attribute returns correct time attributes for committed configuration—In Junos OS Release 12.3R1, when you configured some interfaces using the interface-range configuration statement, if you later requested the committed configuration using the <get-configuration> RPC with the inherit="inherit" and database="committed" attributes, the device returned junos:changed-localtime and junos:changed-seconds in the RPC reply instead of junos:commit-localtime and junos:commit-seconds. This issue is fixed in Junos OS Release 12.3R2 and later releases so that the device returns the expected attributes in the RPC reply.

Network Management and Monitoring

  • New system log message indicating the difference in the Packet Forwarding Engine counter value (ACX Series)—Effective in Junos OS Release 12.3R9, if the counter value of a Packet Forwarding Engine is reported to be less than its previous value, then the residual counter value is added to the newly reported value only for that specific counter. In that case, the CLI shows the MIB2D_COUNTER_DECREASING system log message for that specific counter.


  • In all supported Junos OS releases, regular expressions can no longer be configured if they require more than 64MB of memory or more than 256 recursions for parsing.

    This change in the behavior of Junos OS is in line with the Free BSD limit. The change was made in response to a known consumption vulnerability that allows an attacker to cause a denial of service (resource exhaustion) attack by using regular expressions containing adjacent repetition operators or adjacent bounded repetitions. Junos OS uses regular expressions in several places within the CLI. Exploitation of this vulnerability can cause the Routing Engine to crash, leading to a partial denial of service. Repeated exploitation can result in an extended partial outage of services provided by the routing process (rpd).

Related Documentation

Modified: 2016-06-09