Showing results for 
Search instead for 
Did you mean: 

Cause and effect of VLAN interface throttles?

Level 1
Level 1

I have a Cisco WS-C2950G-12-EI and I have incrementing throttles on my VLAN interface.  How does this impact the performance of the switch, for access ports in the same VLAN 50?  Is this a concern?

Vlan50 is up, line protocol is up
  Hardware is CPU Interface, address is 0021.1b6a.5dc0 (bia 0021.1b6a.5dc0)
  Internet address is
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output never, output hang never
  Last clearing of "show interface" counters 2w1d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 8000 bits/sec, 3 packets/sec
     1181165 packets input, 89737561 bytes, 0 no buffer
     Received 252717 broadcasts (0 IP multicast)
     0 runts, 0 giants, 96 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     4912078 packets output, 430277507 bytes, 0 underruns
     0 output errors, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out

1 Reply 1

paolo bevilacqua
Hall of Fame
Hall of Fame

First of all, the number of throttles compared to input is extremely small.

It happens because switches have very slow CPU and cannot keep up with packet burts.

However, it will not affect performances at all, because switches do switch packets in hardware without involing the CPU at all.

Review Cisco Networking for a $25 gift card