VLAN Interface Traffic Information

[D Prasanna Kumar Reddy]

Hi All,

Could anyone please advice which traffic does VLAN Interface shows ?

For example, I have  two interfaces in VLAN 10, and I have created Layer 3 Interface for VLAN 10.

If i monitor the VLAN 10 Traffic, Do i get both the interfaces combined traffic statistics?

Thanks,

Prasanna Kumar Desireddy

[Mark Malone]

Well if the span source is vlan 10 you will get both but if you set the destination as just say into g0/5 it will just capture that interface alone,are you using span in cli with wireshark or some other tool

[D Prasanna Kumar Reddy]

I am sorry Mark, I didn't get you.

Let me explain my question bit more clearly.

I have two interfaces in a switch -- Fa 0/1 & Fa 0/2. I have assigned these two interfaces to vlan 20.

And then i have created VLAN 20 interface(Layer 3).

If i give "sh interface vlan 20" command, it should show some traffic on interface (5 min or 30 sec).

That traffic is belongs to Fa 0/1 or Fa 0/2 or Both combined traffic ?

Hope you got my concern.

[Mark Malone · Accepted solution]

Oh sorry I thought you were talking about span monitor where you record the interface traffic combined under a vlan

To answer your question it will show the ip layer 3 traffic count in packets for all interfaces combined under the vlan so yes both interfaces will show at the layer 3 vlan interface , some platforms will also show some L2 information  as below and its shows 30 sec count on vlan interfaces but 5 minute count on the physical interface like FA0/1

Vlan149 is up, line protocol is up
  Hardware is EtherSVI, address is 0008.e3ff.fd90 (bia 0008.e3ff.fd90)
  Internet address is x.x.x.x/24
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:14, output never, output hang never
  Last clearing of "show interface" counters 24w4d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  30 second input rate 2134000 bits/sec, 381 packets/sec
  30 second output rate 2019000 bits/sec, 460 packets/sec
  L2 Switched: ucast: 30595061 pkt, 2268569227 bytes - mcast: 0 pkt, 0 bytes
  L3 in Switched: ucast: 5882988002 pkt, 1908218042989 bytes - mcast: 1623 pkt, 775020 bytes
  L3 out Switched: ucast: 5579358870 pkt, 1872959920772 bytes - mcast: 322 pkt, 138259 bytes
     5886751734 packets input, 1885010127367 bytes, 0 no buffer
     Received 0 broadcasts (28 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     5618600472 packets output, 1854023804196 bytes, 0 underruns
     0 output errors, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out

[D Prasanna Kumar Reddy]

Excellent Mark, Many Thanks :-)