07-08-2010 01:32 AM - edited 03-06-2019 11:56 AM
Hello,
I have a simple question that I can't answer.
I have a Cisco 3750 that whenever I pefrom the command "Show interface vlan2222 | i rate " I get the following output:
Cisco3750#show interfaces Vl2222 | i rate
Queueing strategy: fifo
30 second input rate 0 bits/sec, 0 packets/sec
30 second output rate 0 bits/sec, 0 packets/sec
There is definitely traffic passing on this L3 Swtich and I don't understand why it's not providing me with the weight of the VLAN.
Why is the input / output rate at 0? with 0 packets..??
MAV
07-08-2010 09:22 AM
Hello,
You will not see counters on this interface unless traffic is sent TO the IP address of interface vlan 2222 or if traffic is sent FROM the IP address of interface vlan 2222. Traffic that passes through vlan 2222 without hitting the layer 3 address should not generate counters. Try a test, ping the ip of that interface and then check it.
07-20-2010 04:57 AM
I tired perfroming the ping test are you absolutley right.
I began to see the counters..
The problem is that I don't see my traffic...
I checked and the VLAN's ip address configured on the switch is the default gatway for the device passing me traffic.. I don't understand why it's not counting it..
07-20-2010 09:01 AM
I am not sure because I am unaware of your topology and configs, but it could be that the destination host MAC address is already known by the source host thereby not needing to forward traffic to the default gateway. Just a thought, hope it helps.
07-20-2010 09:19 AM
Hello,
If the switch has already build CEF table and switching the data in hardware, then you may not see any increase in the interface counters as all the packets are handled in hardware. You could use the command "show interface stats" to see the traffic through the specific interface. You can also use "show interface accounting" to see type of packets that are punted to the CPU.
Hope this helps.
Regards,
NT
07-20-2010 09:23 AM
Hello,
To add to my earlier post, there is a software defect filed in this regard and the conclusion is that it is the hardware limitaion on the lower end platforms.
Here is the bug ID: CSCsi44166
Hope this helps.
Regards,
NT
07-21-2010 12:42 AM
Thanks again for all your help, it's only fair I shed some more light on what is going on.
The topology?
Cisco 3750 -------------> DSLAM
config of 3750 on interface
interface Vlan2222
description link to DSLAM in question
ip address 10.x.x.115 255.255.255.248
ip access-group 5555 in
no ip redirects
no ip proxy-arp
end
Where the DSLAM's ip address is part of the /29 network, the DSLAM is configured with 10.x.x.115 as the default route.
If I purform the following commands that were suggested this is the output:
show interfaces vlan 2222 stats
Vlan2222
Switching path Pkts In Chars In Pkts Out Chars Out
Processor 1396895 165390042 54579 32861660
Route cache 10202 843179 84 9410
Total 1407097 166233221 54663 32871070
show interfaces vlan 2222 accounting
Vlan2222 link to
Protocol Pkts In Chars In Pkts Out Chars Out
IP 1391534 165082859 49152 32322094
ARP 5505 330300 5512 330720
I think this is a hardware bug..
Let me know what you guys think..
Thanks again for all you help..
PR
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