SRX Services Gateway
SRX Services Gateway

Traffic stopped all of a sudden!

[ Edited ]
‎05-27-2018 08:21 AM

Today we have encountered an interesting problem; the SRX3400 (Software Version: 12.1X46-D25.7) device has stopped all traffic going through its all ports.


We could not understand why it happened as symtopms were below;

- We can ping the Juniper SRX from internal network

- We cannot ping Juniper SRX from DMZ (which we should have)

- We cannot reach Juniper using SSH and Web Management, only Console is working

- We cannot ping local devices from other local devices connected to Juniper SRX of different ports

- When trying to connect by SSH it does somehow accept the connection but hangs for a while and then connection drops

- We can ping or reach to any device connected to Juniper from Juniper SRX device

- The uplink interface was UP however we cannot ping peering IP

- When we look at routing-engine it says; 0.01 Load with %50 memory usage and everything is OK

- There are no alarms in chassis

- There are no alarms in system

- There are no changes in config

- We restart the machine and the problem is gone (!)

- The system was up for 750 days


I am suspecting a hardware failure but I am not sure about it.


What do you think the problem is ?


Additional info:

As I investigate I found thousands of "SIP ALG decode packet error" coming from the same IP address. And when I search it on google, I found this KB:


I believe this caused a DoS.

SRX Services Gateway

Re: Traffic stopped all of a sudden!

‎06-04-2018 09:34 PM

Since you mentioned that console access was available, did you happen to check the RE CPU during the issue (kernel/user % and not load average)?


Also did you check if any particular process was running high CPU?