rxstats.txt file on AVAYA ERS8600

Have you ever noticed a file on your ERS8600's PCMCIA card called "rxstats.txt"?

Well this file is written by the CPU before the port is shutdown by the CP-Limit feature.

You can display the file contents locally on the system with the "more /pcmcia/rxstats.txt" command or you can copy the file off to a server via TFTP/FTP eg "copy /pcmcia/rxstats.txt 10.0.0.2:rxstats.txt" to read with your favorite text editor.



Here is an example output of a rxstats.txt file.

================================================================================
 [MON JUN 24 02:39:07 2013 UTC]: Shutting down port 3/48 for crossing CPP Rate Limit Threshold
 ================================================================================
 
Multicast: 1617 Packets Per Second
Broadcast: 0 Packets Per Second 
 

 Rx Statistics based on Queue Priority
 --------------------------------------------------------------------------------
 
Counters as dumped at MON JUN 24 02:39:05 2013 UTC
 
RxQ#0:         3139
RxQ#1:          222
RxQ#2:         3653
RxQ#3:          749
RxQ#4:          217
RxQ#5:            0

Counters as dumped at MON JUN 24 02:39:07 2013 UTC
 
RxQ#0:         3143
RxQ#1:          222
RxQ#2:         3659
RxQ#3:         3994
RxQ#4:          217
RxQ#5:            0

 Rx Statistics based on Packet Type
 --------------------------------------------------------------------------------

                   
Counters as dumped at MON JUN 24 02:39:05 2013 UTC
 UNKNOWN                   54
 BPDU                       6
 ARP                        5
 OSPF_HELLO               158
 OSPF_DB_DESC              58
 OSPF_LS_ACK             3584
 OSPF_LS_REQ               34
 OSPF_OTHER               744
 SONMP                    157
 TCP_OTHER                  6
 ICMP_ECHO_REPLY            5
 ICMP_ECHO_REQ             30
 VLACP                   3139
 
Counters as dumped at MON JUN 24 02:39:07 2013 UTC
 UNKNOWN                   54
 BPDU                       6
 ARP                        5
 OSPF_HELLO               158
 OSPF_DB_DESC              58
 OSPF_LS_ACK             3590

 OSPF_LS_REQ               34
 OSPF_OTHER              3989
 SONMP                    157
 TCP_OTHER                  6
 ICMP_ECHO_REPLY            5
 ICMP_ECHO_REQ             30
 VLACP                   3143

So you have this file which has dumped a heap of information on your lap and you are probably thinking "Wow, thanks Avaya for providing me with such an informative log" or sometime along those lines.  Well I had the same feeling when I first glanced at this file, expecting the answer to hit me in the face.  Actually when you read the above example carefully you can notice there are two different timestamps throughout the file the first is the time that CP-Limit actually trigged, which in this case is MON JUN 24 02:39:07 2013 UTC and the second is MON JUN 24 02:39:05 2013 UTC, which just happens to be 2 seconds before the event.

So with this new information in hand we can now see clearly what actually trigged the event, which is the "OSPF_OTHER" counter. Two seconds before the trigger this counter value was a measly 744 packets and two seconds later its 3989 packets, which is an increase of 3245 packets. In our case the CP-Limit multicast pps was set to 1500 packets and the event triggered at 1617 pps.  We can roughly calculate this value by dividing the increase of OSPF_OTHER packets by the duration, which is 3245 / 2 = 1622.5.  

While I have obtained a value of 1622 pps I am happy that CP-Limit has saved the CPU on my ERS8600, though I do wish that Avaya would polish this interface to make it easier for people fault finding these types of events.



Please drop me a comment if you have found this post useful or if it requires more information.