From: gladston@br.ibm.com
Date: Thu Aug 11 2005 - 10:51:06 GMT-3
Thanks for the reply Chris,
That is interesting. On the case you showed, IOS does not complain.
But it really disable fair-queue on physical, as Wendell says:
Rack2R5(config)#int ser 0/1
Rack2R5(config-if)#fair-queue
Rack2R5(config-if)#random-detect
Rack2R5(config-if)#do sh run int ser 0/1
interface Serial0/1
ip address 148.5.135.5 255.255.255.0
random-detect
Rack2R5(config-if)#do sh int ser 0/1
Serial0/1 is up, line protocol is up
Hardware is PowerQUICC Serial
Internet address is 148.5.135.5/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 00:00:01, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: random early detection(RED)
5 minute input rate 2000 bits/sec, 0 packets/sec
5 minute output rate 2000 bits/sec, 0 packets/sec
1520 packets input, 1050047 bytes, 0 no buffer
Received 1516 broadcasts, 0 runts, 0 giants, 0 throttles
1 input errors, 0 CRC, 1 frame, 0 overrun, 0 ignored, 0 abort
2666 packets output, 1166529 bytes, 0 underruns
0 output errors, 0 collisions, 15 interface resets
0 output buffer failures, 0 output buffers swapped out
30 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
On the opposite hand, fair-queue is required under CBWFQ class-default to
enable WRED. That is curious.
Cordially,
------------------------------------------------------------------
Gladston
"Chris Lewis \(chrlewis\)" <chrlewis@cisco.com>
11/08/2005 10:39
To
Alaerte Gladston Vidali/Brazil/IBM@IBMBR, <ccielab@groupstudy.com>
cc
Subject
RE: WRED on Physical Interface and CBWFQ
Hi Gladston,
This looks like an order of operation issue. For the physical interface,
if you enter the commands in the same order as the class based
configuration is requesting them, the commands are accepted.
Starting here:
!
interface Serial1/0
ip address 131.108.50.1 255.255.0.0
!
The commands can be applied as follows:
R1(config)#int s1/0
R1(config-if)#fair-queue
R1(config-if)#random-detect
Chris
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
gladston@br.ibm.com
Sent: Thursday, August 11, 2005 8:10 AM
To: ccielab@groupstudy.com
Subject: WRED on Physical Interface and CBWFQ
Hi,
Do you know what is the logic behind the following behavior of IOS?
Under class-default of CBWFQ, WRED requires fair-queue to be configured.
Under physical interface, WRED requires fair-queue to be removed.
Tests:
WRED applyed on class-default
Rack2R5(config-pmap)#class class-default
Rack2R5(config-pmap-c)#random-detect dscp-b fair-queue or bandwidth on
the class is required to issue this command
Rack2R5(config-pmap-c)#fair-queue Rack2R5(config-pmap-c)#random-detect
dscp-b
WRED applyed on physical:
Rack2R5(config-if)#int ser 0/1
Rack2R5(config-if)#fair-queue
Must remove RED configuration first.
This archive was generated by hypermail 2.1.4 : Sun Sep 04 2005 - 17:01:19 GMT-3