The Right Count Way That Interface Traffic Count is Inaccurate Lies in Large Interface Traffic of USG3040

Publication Date:  2012-09-14 Views:  190 Downloads:  0
Issue Description
The 2 grade carrier uses USG3040 that hang many Internet users, but the traffic on external interface of USG3040 is small, it is found that the interface traffic reached 500M/s by network management soft. 
Alarm Information
NULL 
Handling Process
1. Command: disp interface GigabitEthernet 0/0
look up interface traffic count

    Last 5 minutes input rate 3845358  bytes/sec, 69792  packets/sec
    Last 5 minutes output rate 9827411  bytes/sec, 53967  packets/sec

From the interface traffic analysis, we can find that the out and in packets number of external network interface are 53967 pps and 69792 pps, traffic number are 9827411  bytes/sec和3845358  bytes/sec, they are small.

2. Clear interface traffic count, take the interface byte number divided by packets number, get: internal interface packets size is 854 bytes, external interface packets size is 185 bytes.

    Input: 291436 packets, 249158327 bytes
           0 broadcasts: 0.00 percent of all the input packets
           0 multicasts: 0.00 percent of all the input packets
           0 errors.
               0 runt error,    0 oversize error, 0 CRC error
               0 length error,  0 code error,     0 dribble error
               0 other errors
    Output:229714 packets, 42503047 bytes
           0 broadcasts: 0.00 percent of all the output packets
           0 multicasts: 0.00 percent of all the output packets
           0 errors.
               0 collision error, 0 late col.error
               0 ex col.  error, 0  FCS      error
               0 abort    error, 0  runt      error
               0 over size error

3. According step 1 and 2, take 5 minutes packets count number, the out and in packets number of external network interface are 450 Mpps and 75Mpps.
Root Cause
The count of interface traffic is small because of the count overbrimed overturn of interface byte number when the traffic is too much. 
Suggestions
NULL 

END