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Verifying PIC Combinations (Junos OS)

On Juniper Networks routing platforms, you can typically install any combination of Physical Interface Cards (PICs) on a single Enhanced Flexible PIC Concentrator (FPC) or in two PIC slots served by a single Layer 2/Layer 3 Packet Processing application-specific integrated circuit (ASIC).

Newer Junos OS services for some PICs can require significant Internet Processor ASIC memory, and some configuration rules limit certain combinations of PICs if they are installed on some platforms.

During software installation, the configuration checker in the installation program checks the router’s PICs. If any configuration rules affect your PIC combinations, the installation process stops and displays a message similar to the following:

The configuration checker has the following limitations:

  • If a PIC is offline when you upgrade the router with new software, the configuration checker cannot detect PIC combinations affected by configuration rules and cannot warn about them.

  • If you specify the force option when you upgrade the Junos OS, the configuration checker warns about the affected PIC combination and the software installation continues. However, after rebooting, one or more PICs might fail to initialize.

  • The configuration checker looks for combinations of three affected PICs. If an Enhanced FPC contains four affected PICs, the script generates multiple warnings.

If you install a PIC into a router already running Junos OS, you can identify the presence of affected PIC combinations from messages in the system logging (syslog) file:

For more information about checking for unsupported PIC combinations, see the corresponding PIC guide for your router, the Junos OS Release Notes, and Technical Support Bulletin PSN-2004-12-002, PIC Combination Notes Summary on the Juniper Networks Support Web site at

For SRX Series Services Gateways

SRX5600 and SRX5800 devices support IOC or SPC on any given card slot, and there is no complexity in equipping the services gateways with the perfect balance of processing and I/O capacity. You can install up to 11 (on SRX5800) and 5 (SRX5600) SPCs and IOCs on the device. However, you must install at least one SPC on device. For more details, see SRX5600 and SRX5800 Services Gateway Card Guide.

SRX3600 supports a maximum of up to seven SPCs,three NPCs, six IOCs, and 11 NP-IOCs per chassis. However you must install at least one SPcs and NPC on the chassis. SRX3400 supports a maximum of up to four SPCs,two NPCs, four IOCs, and six NP-IOCs per chassis. However you must install at least one SPcs and NPC on the chassis. On SRX3400 and SRX3600 devices you must install PICs on the front slots of the chassis. For more details, see SR X1400 , SRX3400 , and SRX3600 Services Gateway Module Guide.