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Changes in Behavior and Syntax
This section lists the changes in behavior of Junos OS features and changes in the syntax of Junos OS statements and commands from Junos OS Release 17.4R2 for MX Series routers.
Changes in the output of show route table command—Starting in Junos OS Release 17.4R2, the output for show route table no longer displays the loopback address as the route distinguisher for MAC address virtual routing and forwarding (MAC-VRF) routing instances route entries. Instead, the output now displays the route distinguisher for the evpn and virtual switch instance type.
Support for LSP on EVPN-MPLS—Starting in Junos OS Release 17.4R2, Junos supports the mapping of EVPN traffic to specific label-switched paths (LSPs). Prior to this release, the traffic policies mapping extended community to specific LSPs did not work properly.
Changes in the show route extensive output—Starting in Junos OS Release 17.4R2, the output for show route extensive displays unknown evpn, opaque, and experimental extended communities as follows:
EVPN: unknown iana evpn 0xtype:0xsubtype:0xvalue
OPAQUE: unknown iana opaque 0xtype:0xsubtype:0xvalue
EXP: unknown 0xtype:0xsub-type:0xvalue
where type, sub-type, and value are defined in RFC 4360 BGP Extended Communities Attribute, RFC7153 IANA Registries for BGP Extended Communities. Internet Assigned Numbers Authority (IANA) maintains a registry with information on the type and subtype field values at https://www.iana.org/assignments/bgp-extended-communities/bgp-extended-communities.xhtml
High Availability (HA) and Resiliency
Command ‘show chassis in-service-upgrade’ not available (MX10003)—In this release, the command "show chassis in-service-upgrade" is not available for MX10003 routers. If you enter this command, the following output is shown: "error: command is not valid on the JNP10003 [MX10003]". Earlier, the output shown for this command was "error: Unrecognized command (chassis-control)".
Interfaces and Chassis
Deprecated maximum transmission unit configuration option for virtual tunnel interfaces—In Junos OS Release 17.4R1, you cannot configure the maximum transmission unit (MTU) size for virtual tunnel (vt) interfaces, because the mtu bytes option is deprecated for vt interfaces. Junos OS sets the MTU size for vt interfaces by default to unlimited.
Modified output of the request vmhost zeroize command—Starting with Junos OS Release 17.2, the command request vmhost zeroize, upon execution, prompts the user for confirmation to proceed. The following line is displayed:
user@host request vmhost zeroize VMHost Zeroization : Erase all data, including configuration and log files ? [yes,no] (no) yes
Modified output of the show chassis ethernet-switch command—The ports 24 and 26 on the MX240, MX480, and MX960 routers with the RE-S-X6-64G Routing Engines are dedicated for external Ethernet connectivity. The show chassis ethernet-switch command on these routers displays the link status for these ports as External Ethernet. .
Recovery of PICs that are stuck because of prolonged flow controls (MS-MIC, MS-MPC, MS-DPC, MS-PIC 100, MS-PIC 400, and MS-PIC 500)—Starting in Junos OS Release 16.1R7, if interfaces on an MS-PIC, MS-MIC, MS-MPC, or MS-DPC are in stuck state because of prolonged flow control, Junos OS restarts the service PICs to recover them from this state. However, if you want the PICs to remain in stuck state until you manually restart the PICs, configure the new option up-on-flow-control for the flow-control-options statement at the [edit interfaces mo-fpc/pic/port multiservice-options] hierarchy level. In releases before Release 16.1R7, there is no action taken to recover service PICs from this state unless one of the options for the flow-control-options statement is configured, or service PIC is manually restarted.
Changes to Junos OS YANG module naming conventions (MX Series)—Starting in Junos OS Release 17.4R1, the native Junos OS YANG modules use a new naming convention for the module's name, filename, and namespace. The module name and filename include the device family and the area of the configuration or command hierarchy to which the schema in the module belongs. In addition, the module filename includes a revision date. The module namespace is simplified to include the device family, the module type, and an identifier that is unique to each module and that differentiates the namespace of the module from that of other modules.
Support for adjusting the threshold of autobandwidth based on the absolute value for LSP (MX Series)—Current autobandwidth threshold adjustment is done based on the configured percentage which is hard to tune to work well for both small and large bandwidth reservations. For a given threshold percentage, when the bandwidth reservation is small there can be multiple LSP resignaling events. This is because the LSP is responsive to even minor increases or decreases in the utilization when current reservation is small. For example, a small threshold adjustment of 5 percent allows large LSPs of around 1G to respond to changes in bandwidth of the order of 50M. However, that same threshold adjustment results in too many LSP resignalling events for small LSPs of around 10M reservation. Increasing the adjust threshold percentage by for example 40 percent minimizes LSP resignaling for small LSPs. However, large LSPs do not react to bandwidth usage changes unless they are huge, for example, 400M. Starting in Junos OS Release 17.4R1, you can configure an absolute value-based threshold along with the percentage-based threshold that helps avoid the bandwidth getting triggered for LSPs of both small and large bandwidth reservations. Configure adjust-threshold-absolute value option at the [edit protocols mpls label-switched-path lsp-name auto-bandwidth] hierarchy level.
Support for label history for MPLS protocol (MX Series)—Starting in Junos OS Release 17.4R1, configure max-entries number option at the [edit protocols mpls label-history] hierarchy level to display label allocation, release history, and associated information such as RSVP session that helps debug label related error such as stale label route and deleted label route. You can configure the limit for the maximum number of MPLS history entries per label . By default, label history is off and there is no maximum limit for the number of entries for each label. The show mpls label history label-value command displays the label history for a given label value and the show mpls label history label-range start-label end-label command displays the history of labels between the given label range.
The clear mpls label history command clears the label history details.
Support for default time out duration for self-ping on an LSP instance (MX Series)—Starting in Junos OS 17.4R1, the default time out duration for which the self-ping runs on an LSP instance is reduced from 65,535 (runs until success) to 1800 seconds. You can also configure the self-ping duration value between 1 to 65,535 (runs until success) seconds using the self-ping-duration value command at the [edit protocols mpls label-switched-path label-switched-path] hierarchy level. By default, self-ping is enabled. The LSP types like CCC, P2MP, VLAN-based , and non-default instances do not support self-ping . You can configure no-self-ping command at the [edit protocols mpls label-switched-path label-switched-path] hierarchy level to override the behavior of self-ping running by default.
Support for Flap and MBB counter for LSP (MX Series)—Starting in Junos OS Release 17.4R1, the show mpls lsp extensive command introduces the following two counters for LSP on the master routing engine (RE) only:
Flap counter–- Counts the number of times a LSP flaps down or up.
MBB counter— Counts the number of times a LSP incurs MBB.
The clear mpls lsp counters command resets the flap and the MBB counter to zero.
Support for inet.0 and inet.3 labeled unicast BGP route for protocol LDP (MX Series)--- Starting in Junos OS Release 17.4R2, LDP egress policy is supported on both inet.0 and inet.3 routing Information bases (RIBs) also known as routing table for labeled unicast BGP routes. If a routing policy is configured with a specific (inet.0 and inet.3) RIB, the egress policy is applied on the specified RIB. If no RIB is specified and a prefix is present on both inet.0 and inet.3 RIBs for labeled unicast BGP routes, then inet.3 RIB is preferred. However, prior to Junos OS Release 12.3R1 and starting with Junos OS Release 16.1R1, LDP egress policy is always preferred on inet.0 RIB and support for inet.3 RIB egress policy for labeled unicast BGP routes was disabled. In Junos OS Release 12.3R1 and later releases up to Junos Release 16.1R1, LDP egress policy was supported in inet.3 RIBs, in addition to inet.0 RIBs, for labeled-unicast BGP routes.
New output fields to monitor LSP resignaling count—Starting in Junos OS Release 17.4R1, the show mpls lsp command output displays the Flap Count and MBB Count output fields, that capture the historical count of the number of times a specific LSP has been resignaled because of autobandwidth-triggered reservation change, or other changes along the path. The flap count displays the number of times an LSP flaps down and up, and the MBB count displays the number of times an LSP incurred a make before break.
Display of labels in received record route for unprotected LSPs by show mpls lsp extensive command (MX Series)—The show mpls lsp extensive command displays the labels in received record route (RRO) for protected LSPs. Starting in Junos OS Release 17.4R1, the command also displays the labels associated with the hops in RRO for unprotected LSPs as well. The label recording in RRO is enabled by default.
Starting in Junos OS Release 17.4R1, a new configuration statement - adjust-threshold-absolute - is introduced at the [edit protocols mpls] hierarchy level to specify the changes in the average label-switched path (LSP) utilization to trigger automatic bandwidth adjustment in bits per second (bps).
Currently, this change is specified as a percentage using the adjust-threshold statement. The adjust-threshold-absolute statement (bps) can be used in conjunction with the existing adjust-threshold statement (percent).
Starting in Junos OS Release 17.4R1, the spring-traffic-engineering statement at the [edit protocols] hierarchy level is replaced with the source-packet-routing statement, although the support for the spring-traffic-engineering statement is provided as an alias. This replacement does not introduce any functionality change, and is intended for maintaining consistency across the terms used in Source Packet Routing in Networking (SPRING) or segment routing features.
Support for rpf-selection statement for PIM protocol at global instance level (MX Series)—Starting in Junos OS 17.4R1, the rpf-selection statement for the PIM protocol is available at global instance level. You can configure group and source statements at the [edit protocols pim rpf-selection] hierarchy level.
Network Management and Monitoring
Customer-visible SNMP trap name changes (MX Series)—In Junos OS Release 17.4R1, on Enhanced Switch Control Board (SCBE), name changes include the CB slot when jnxTimingFaultLOSSet and jnxTimingFaultLOSClear traps are generated in the case of BITS interfaces (T1 or E1). SNMP traps for the backup Routing Engine clock failure event have been added and the control board name is included in the SNMP trap interface name (jnxClksyncIntfName), for example, value: "external(cb-0)".
[See SNMP MIB Explorer.]
SNMP syslog messages changed (MX Series)—In Junos OS Release 17.4R1, two misleading SNMP syslog messages have been rewritten to accurately describe the event:
OLD —AgentX master agent failed to respond to ping. Attempting to re-register
NEW —AgentX master agent failed to respond to ping, triggering cleanup!
OLD —NET-SNMP version %s AgentX subagent connected
NEW —NET-SNMP version %s AgentX subagent Open-Sent!
[See the SNMP MIB Explorer.]
Change in default log level setting (MX Series)—In Junos OS Release, 17.4R1, the following changes were made in default logging levels:
Before this change:
SNMP_TRAP_LINK_UP was LOG_INFO for both the physical (IFD) and logical (IFL) interfaces.
SNMP_TRAP_LINK_DOWN was LOG_WARNING for both the physical (IFD) and logical (IFL) interfaces.
After this change:
IFD LinkUp -> LOG_NOTICE (because this is an important message but less frequent)
IFL LinkUp -> LOG_INFO (no change)
IFD and IFL LinkDown -> LOG_WARNING (no change)
[See the MIB Explorer.]
New context-oid option for trap-options configuration statement to distinguish the traps which come from a non-default routing instance and non-default logical system (MX Series)—In Junos OS Release 17.4R2, a new option, context-oid, for the trap-options statement allows you to handle prefixes such as <routing-instance name>@<trap-group> or <logical-system name>/<routing-instance name>@<trap-group> as an additional varbind.
Option to configure SPRING bandwidth utilization change threshold in percentage(MX Series)—Starting in Junos OS Release 17.4R1, you can specify a change threshold in percentage beyond which RSVP triggers IGP updates. To configure the change threshold percentage, configure percent percent at the [edit protocols rsvp interface update-threshold-max-reservable] hierarchy level.
BGP enterprise trap jnxBgpM2BackwardTransition notification for IPv4 neighbors (MX Series)—Starting in Junos OS Release 17.4R2, when an IPv4 BGP neighbor transitions from a higher state to a lower state, an enterprise trap jnxBgpM2BackwardTransition is sent in addition to an existing standard trap notification bgpM2BackwardTransition. In earlier Junos OS releases only bgpBackwardTransition trap notification was generated when a BGP IPv4 neighbor’s state transitioned to a lower state.
Support to log the SSH key changes—Starting with Junos OS 17.4R1, the configuration statement log-key-changes is introduced at the [edit system services ssh ] hierarchy level. When the log-key-changes configuration statement is enabled and committed (with the commit command in configuration mode), Junos OS logs the changes to the set of authorized SSH keys for each user (including the keys that were added or removed). Junos OS logs the differences since the last time the log-key-changes configuration statement was enabled. If the log-key-changes configuration statement was never enabled, then Junos OS logs all the authorized SSH keys.
Accurate value in exported inline flow monitoring records for MPLS-over-GRE tunnels—Starting in Junos OS Release 17.4R1, the exported flow records for inline flow monitoring of traffic entering MPLS-over-GRE tunnels (also known as next-hop-based dynamic GRE tunnels) contain the correct values in the gateway address and outgoing interface fields. Prior to Junos OS Release 17.4R1, these fields contained a value of 0.
Software Defined Networking
The 32-bit libstdc++ package no longer required for Junos Node Slicing setup—Starting in Junos OS Release 17.4R2, you need not install the additional 32-bit libstdc++ package for Red Hat Enterprise Linux (RHEL) or Ubuntu to set up Junos Node Slicing.
Software Installation and Upgrade
ZTP is supported on MX PPC platforms (MX Series)—As of Junos OS Release 17.2R3, zero touch provisioning (ZTP) is supported on MX PPC platforms (which are MX5, MX10, MX40, MX80, and MX104 routers). Before the fix, the ZTP process did not start to load image and configuration for MX PPC routers.
Key generator adds one day to make the duration of license show as 365 days (MX Series)—Starting in Junos OS Release 17.4R1, the duration of subscription licenses as generated by the show system license command and shown in the output is correct to the numbers of days. Before this fix, for example, for a 1-year subscription license, the duration was generated as 364 days. After the fix, the duration of the 1-year subscription now shows as 365 days.
[See show system license.]
Subscriber Management and Services
Correct SNMP index value in exported inline flow monitoring records for BNG subscribers—Starting in Junos OS Release 17.4R1, the exported flow records for inline flow monitoring report the SNMP index of the broadband network gateway (BNG) subscriber’s interface. Prior to Junos OS Release 17.4R1, the flow records reported the SNMP index of the underlying interface (PPPoE encapsulated interface), which caused incorrect values in the derived fields (mask, outgoing interface, gateway address).
Configure nexthop-learning enable at the [edit services flow-monitoring (version-ipfix | version9) template template-name] hierarchy level to get the correct outgoing interface and gateway address values for subscriber traffic in the following situations:
Ingress and egress VRF are not the same.
Traffic is load balanced.
Traffic is forwarded through a composite next hop (for example, an MPLS over GRE tunnel).
Memory mapping statement removed for Enhanced Subscriber Management (MX Series)— Starting in Junos OS Release 17.3R1, use the following command when configuring database memory for Enhanced Subscriber Management:
set system configuration-database max-db-size
CLI support for the set configuration-database virtual-memory-mapping process-set subscriber-management command has been removed to avoid confusion. Using the command for subscriber management now results in the following error message:
WARNING: system configuration-database virtual-memory-mapping not supported. error: configuration check-out failed.
[See Interface Configuring Junos OS Enhanced Subscriber Management for an example of how to use the max-db-size command.]
Support for IPv6 all-routers address in nondefault routing instance (MX Series)—Starting in Junos OS Release 17.4R2, the well-known IPv6 all-routers multicast address, FF02::2, is supported in nondefault routing instances. In earlier releases it is supported only for the default routing instance; consequently IPv6 router solicitation packets are dropped in nondefault routing instances.
Correction to CLI for L2TP tunnel keepalives (MX Series)—Starting in Junos OS Release 17.4R2, the CLI correctly limits to 3600 seconds the maximum duration that you can enter for the hello interval of an L2TP tunnel group. In earlier releases, the CLI allows you to enter a value up to 65,535, even though only 3600 is supported.
Wildcard supported for show subscribers agent-circuit-identifier command (MX Series)—Starting in Junos OS Release 17.4R2, you can specify either the complete ACI string or a substring when you issue the show subscribers agent-circuit-identifier command. To specify a substring, you must enter characters that form the beginning of the string, followed by an asterisk (*) as a wildcard to substitute for the remainder of the string. The wildcard can be used only at the end of the specified substring; for example:user@host1> show subscribers agent-circuit-identifier substring*
In earlier releases, starting with Junos OS Release 14.1, the command requires you to specify the complete ACI string to display the correct results. In Junos OS Release 13.3, you can successfully specify a substring of the ACI without a wildcard.
Changed behavior for framed routes without a subnet mask (MX Series)—Starting in Junos OS Release 17.4R2, the router connects the session but ignores a framed route when it is received from RADIUS in the Framed-Route attribute (22) without a subnet mask.
In earlier releases, the router installs the framed route with a Class A, B, or C subnet mask depending on the value of the first octet. When the octet < 128, the mask is /8; when 128 <= octet < 192, the mask is /16; and when the octet >= 192, the mask is 24.
DHCPv6 lease renewal for separate IA renew requests (MX Series)—Starting in Junos OS Release 17.4R2, the jdhcpd process handles the second renew request differently in the situation where the DHCPv6 client CPE device does both of the following:
Initiates negotiation for both the IA_NA and IA_PD address types in a single solicit message.
Sends separate lease renew requests for the IA_NA and the IA_PD and the renew requests are received back-to-back.
The new behavior is as follows:
When the reply is received for the first renew request, if a renew request is pending for the second address type, the client stays in the renewing state, the lease is extended for the first IA, and the client entry is updated.
When the reply is received for the second renew request, the lease is extended for the second IA and the client entry is updated again.
In earlier releases:
The client transitions to the bound state instead of staying in the renewing state. The lease is extended for the first IA and the client entry is updated.
When the reply is received for the second renew request, the lease is not renewed for the second address type and the reply is forwarded to the client. Consequently, when that lease ages out, the binding for that address type is cleared, the access route is removed, and subsequent traffic is dropped for that address or address prefix.
User Interface and Configuration
Junos OS prohibits configuring ephemeral configuration database instances that use the name default (MX Series)—Starting in Junos OS Release 17.4R2, user-defined instances of the ephemeral configuration database, which are configured using the instance instance-name statement at the [edit system configuration-database ephemeral] hierarchy level, do not support configuring the name default.