04-22-2009 12:21 PM - edited 03-06-2019 05:19 AM
Does the 3750 FastEthernet ports provide any other queueing option than FIFO?
04-22-2009 12:58 PM
3750 supports fair-queuing and random-detect as well.
Rack1SW1#sh run int f0/1
Building configuration...
Current configuration : 72 bytes
!
interface FastEthernet0/1
switchport access vlan 14
fair-queue
end
Rack1SW1#sh int f0/1 | i Queueing
Queueing strategy: weighted fair
Rack1SW1(config-if)#random-detect
Rack1SW1#sh int f0/1 | i Queueing
Queueing strategy: random early detection(RED)
For more information, refer to the documentation:
HTH,
__
Edison.
04-22-2009 01:24 PM
Thanks much Edison.
Here's my problem. My 3750 does not have these queueing commands available for my FastEthernet ports.
Here's what I have
cisco WS-C3750-48TS (PowerPC405)
(C3750-IPSERVICESK9-M), Version 12.2(50)SE
04-22-2009 01:30 PM
That's odd. My output above was taken from a 3560 running 12.2(25)SEE - sorry I don't have a 3750 switch at the moment but both should share the same set of commands.
Do you have the port configured in layer2 mode (switchport) or layer3 mode (no switchport)?
__
Edison.
04-22-2009 01:40 PM
Layer-2 with Q-Trunking
interface FastEthernet1/0/1
description CONNECTION TOWARDS CHICAGO
switchport trunk encapsulation dot1q
switchport mode trunk
bandwidth 45000
load-interval 30
speed 100
duplex full
srr-queue bandwidth limit 10
spanning-tree portfast
04-23-2009 07:50 AM
Peter,
After further research, the commands I demonstrated on my original post are/were available in some version of IOS in the Catalyst switches but they aren't supported on that type of hardware.
The available queueing strategies are described in the link I provided, which are: WTD and SRR.
I see you are using SRR for bandwidth limiting and you can also use SRR for sharing and shaping of queues.
Please take a moment and read the link I provided on the 2 queuing options available. The 3750 has limited options in term of QoS as its marketed as a desktop switching solution, not a distribution|core switching solution.
You may also benefit from reading the QoS SRND:
http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.html
HTH,
__
Edison.
04-22-2009 04:00 PM
"Does the 3750 FastEthernet ports provide any other queueing option than FIFO?"
Yes and no. The 3750 provides 4 output FIFO queues per interface with weighted tail drop. The reference Edison provided explains further (although you should use the manuals for your release [which he didn't know at the time he provided it]).
PS:
Regarding Edison noting FQ support in his release but not found in yours, the configuration guide, for his version, notes in Appendix C, page C-5, it's an unsupported interface command, see http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_25_see/configuration/guide/3560SCG.pdf
04-23-2009 07:20 AM
Okay. So I downloaded the configuration guide, but I'm not really following you. Sorry.
I've read lots of manuals and couldn't find anything about queuing other than what I see defined on the interface by default (FIFO). Can someone show me on a 3750 running this release?
Thanks
04-23-2009 03:43 PM
Just want to confirm you've read: http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_50_se/configuration/guide/swqos.html.
When you write "what I see defined on the interface by default", what do you mean? QoS stats on this platform are not shown as they are on routers. What are you "seeing"?
04-27-2009 05:16 AM
Sorry about the delayed response. Here's a "show interface" output. Queueing Strategy is FIFO.
Peter
MRHONGCG01RGW01#show int fa1/0/1
FastEthernet1/0/1 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 000f.34f0.1b03 (bia 000f.34f0.1b03)
Description: CONNECTION TOWARDS CHICAGO
MTU 1500 bytes, BW 45000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, media type is 10/100BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:01, output hang never
Last clearing of "show interface" counters 4d16h
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/0 (size/max)
30 second input rate 6000 bits/sec, 8 packets/sec
30 second output rate 3000 bits/sec, 4 packets/sec
3366507 packets input, 595882008 bytes, 0 no buffer
Received 2440100 broadcasts (2440060 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 2440060 multicast, 0 pause input
0 input packets with dribble condition detected
1822391 packets output, 480478260 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
MRHONGCG01RGW01#
04-27-2009 06:47 AM
I suspect an "regular" show interface may not accurately depict output queuing on a 3750. You can also see in your stats "Output queue: 0/0 (size/max", and I doubt the maximum queue size is zero.
04-28-2009 01:13 PM
Okay. I appreciate your suppport.
So, where are we at. Not sure if we've answered the question on queueing strategy?
04-28-2009 01:34 PM
The 3750 supports 4 FIFO queues per interface. There are options on how each is dequeued relative to others, how buffers space is allocated, and various tail drops limits. The QoS chapter in the configuration guide explains these feature. If you have not read it, suggest you do. If you still have questions, post again.
05-04-2009 06:09 PM
Thanks. I plan on looking into this within the next few days.
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