Crashing Juniper M7i router by IP over ATM VC
Friday, June 2nd, 2006Today, my fiend and me already tested the IP over ATM capability with ATM-II interface in Juniper.
We used 2xM7i routers with these specification:
- RE Memory: 512 MB
- FEB memory: 128 MB
- ATM interface: 2x OC-3 ATM-II IQ, SMIR
We put both router in back to back configuration
Router1—–(IPoATM interface)——Router2
And these are the conclusion:
1. Maximum vci defined is 16346, excluding the reserved VCI number based on ATM forum standard.
2. we still able to do ping up to VCI number 11950.
3. This is status inside first router, without any configuration except this ATM interface:
admin@TEST> show chassis routing-engine
Routing Engine status:
Temperature 39 degrees C / 102 degrees F
CPU temperature 44 degrees C / 111 degrees F
DRAM 512 MB
Memory utilization 97 percent
CPU utilization:
User 95 percent
Background 0 percent
Kernel 5 percent
Interrupt 1 percent
Idle 0 percent
Model RE-5.0
Serial ID *********
Start time 2006-04-21 07:29:01 UTC
Uptime 42 days, 3 hours, 59 minutes, 50 seconds
Load averages: 1 minute 5 minute 15 minute
1.95 1.41 1.60
admin@TEST> show chassis cfeb
CFEB status:
State Online
Intake temperature 35 degrees C / 95 degrees F
Exhaust temperature 41 degrees C / 105 degrees F
CPU utilization 100 percent
Interrupt utilization 0 percent
Heap utilization 62 percent
Buffer utilization 28 percent
Total CPU DRAM 128 MB
Internet Processor II Version 2, Foundry IBM, Part number 164
Start time: 2006-04-21 07:30:30 UTC
Uptime: 42 days, 4 hours, 19 minutes, 48 seconds
4. I don’t know exactly about the maximum number of VC that can handled by second router, because the second router was crash. The second router was not as strong as first router because we have many other config inside there. There were some VRF and MPLS configuration inside second router.
Seems that all of those another configuration was decreasing the memory and cpu capacity.
This is the log in the console:
——————————-
panic: Loss of soft watchdog
panic(c042a696,d3,0,c040daa0,c29fc84) at panic+0×96
statclock(dad95fa0,8,d3,c040d64c) at statclock+0×141
rtcintr(0,0,a400002f,81f002f,bfbf002f) at rtcintr+0×14
Xresume8() at Xresume8+0×2b
— interrupt, eip = 0×8084c73, esp = 0xdad95fe0, ebp = 0xbfbfbc08 —
syncing disks…
done
Uptime: 10m29s
Selective dump
dumping to dev rad1s1b, offset 942616
ata0: resetting devices .. done
50 49 48 47 46 45 44 43 42 41 40 39 failed, reason: aborted from console
ata0: Spinning down devices. Please wait…
Automatic reboot in 15 seconds - press a key on the console to abort
5. The other important thing that we found is we can proof what JTAC said. Few days before, I have problem that I can only have up to around 500 VC.
From JTAC, thanks to them, we knew that the memory allocation for this ATM interface is divided into 512 ATM descriptor pages. Each pages can consist of 32 VCI in sequencial order.
So theoritically we can have up to 32 x 512 = 16384 VCI if the VCI is in sequential order and only 512 VCI if we have 32 in gap between VCI. And finally, we proofed it.
at-0/0/0.506 up up inet 10.12.31.146/30
at-0/0/0.507 up up inet 10.12.31.162/30
at-0/0/0.508 up up inet 10.12.31.178/30
at-0/0/0.509 up up inet 10.12.31.194/30
at-0/0/0.510 up up inet 10.12.31.210/30
at-0/0/0.511 up up inet 10.12.31.226/30
at-0/0/0.512 up up inet 10.12.31.242/30
at-0/0/0.513 up down inet 10.12.32.2/30
at-0/0/0.514 up down inet 10.12.32.18/30
at-0/0/0.515 up down inet 10.12.32.34/30
at-0/0/0.516 up down inet 10.12.32.50/30
at-0/0/0.517 up down inet 10.12.32.66/30
at-0/0/0.518 up down inet 10.12.32.82/30
6. I also do the test in term of VPI number, we still able to have more than 8 VP in one time.
7. The limitation definietely located in number of VC.
After being happy because successfully crashing this Juniper M7i, i am confused about how to restore the router from kernel panic. Each time i restart the router, the config is automatically loaded and make the router crash again.
After some trial and error and ask my friend, i tried to ctrl-c when the OS still in loading progress, and as standard FreeBSD, by pressing ctrl-c, all startup process is skipped. I finally able to log in to the system by using system root login but i can not access the JunOS CLI.
So, i tried to gunzip the saved old config in /config directory and copy it as juniper.conf
After issued command “shutdown -r now”, i get the router back in normal configuration.
-rendo-
