[afnog] CFEB issues on juniper

Mark Tinka mtinka at globaltransit.net
Tue Feb 7 10:45:08 UTC 2012

On Tuesday, February 07, 2012 06:24:02 PM ibtisam jamal wrote:

> @SR01> show chassis cfeb
> CFEB status:
> Slot 0 information:
>   State                                 Backup
> Slot 1 information:
>   State                                 Master
>   Intake temperature                 25 degrees C / 77 degrees F
>   Exhaust temperature                31 degrees C / 87 degrees F
>   CPU utilization                    56 percent
>   Interrupt utilization               5 percent
>   Heap utilization                   84 percent

Yep, that'll be your problem.

Your heap utilization is very high, indicating
that the CFEB is running out of FIB slots, and
as such, cannot install the routing entries as
mentioned in the logs.

Unlike some Cisco devices, the Juniper won't
fall back to software forwarding, so any traffic
destined for the routes that couldn't get installed
in the FIB will be blackholed.

> @SR01> show chassis hardware
> Hardware inventory:
> Item             Version  Part number  Serial number     Description
> Chassis                                A3583             M10i
> Midplane         REV 06   710-008920   DC0193            M10i Midplane
> Power Supply 0   Rev 04   740-008985   TA50568           DC Power Supply
> Power Supply 1   Rev 04   740-008985   TB52654           DC Power Supply
> HCM 0            REV 04   710-010580   DE0720            M10i HCM
> HCM 1            REV 04   710-010580   DE0820            M10i HCM
> Routing Engine 0 REV 12   740-009459   1000672632        RE-5.0
> CFEB 0           N/A      N/A          N/A               Backup
> CFEB 1           REV 12   750-010465   AAAT6186          Internet Processor
> II

Yep, you also have the standard CFEB's that ship
with the M7i/M10i. If you want a lot more FIB
space, you want the Enhanced CFEB, which comes with
32MB RLDRAM (as opposed the the standard CFEB which
ships with only 8MB SSRAM).

These are your options:

	1. Maintain the CFEB you currently have but reduce
	   the number of routes (inet.0, l2vpn, l3vpn, vpls,
	   e.t.c.) that need to be installed in the FIB. Upgrade
  	   your standard CFEB to 256MB DRAM though (although 
	   that does not help with FIB exhaustion - that's just
	   for packet buffering).

	2. Maintain the CFEB you have now and reboot the
	   router. This is a very short-term fix. If your
	   routing remains the way it is now, chances are
	   you will run into the same issue again sooner
	   than you think. Upgrade your standard CFEB to
 	   256MB DRAM (although that does not help with FIB
	   exhaustion - those are just for packet buffering).

	3. Upgrade to the Enhanced CFEB. These days, if
	   you're buying new M7i's or M10i's, the Enhanced
	   CFEB is the only one that is shipped. Otherwise,
	   keeping costs down means pre-owned dealers will
	   more often sell you the standard CFEB.

Operators around the world will be seeing more and
more of these kinds of problems as the Internet routing 
table continues to explode, and older architectures (like
the standard M7i/M10i CFEB, older Juniper routers, older
Cisco 6500/7600 supervisor modules like the SUP720-3B,
SUP32, SUP2, e.t.c.) keep running the network.

Hope this helps.


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