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Hold the Door!!! CCIE 25938: CCIE Routing & Switching, Security,Voice, and latest CCIE Datacenter. Python+SDN is on going

Saturday, January 28, 2012

Cos-to-DSCP:
By default CoS-to-DSCP :
CoS-DSCP map :

cos:   0     1      2      3       4      5     6      7
---------------------------------------------------------
dscp :0    8    16    24    32    40    48    56


Using following command to change this map on switch:

switch(config)# mls qos map cos-dscp dscp1 dscp2 dscp3 dscp4 dscp5 dscp6 dscp7 dscp8

DSCP-to-CoS:
By default DSCP-to-CoS map:


DSCP CoS
0~7 0
8~15 1
16~23 2
24~31 3
32~39 4
40~47 5
48~55 6
56~63 7

Use following command to check switch map table:
swtich#show mls qos maps dscp-qos

To change DSCP -to-Cos map , use this command:

switch(config)# mls qos map dscp-cos dscp1 dscp2 dscp3 dscp4 dscp5 dscp6 dscp7 dscp8 to cos


Summary: 

DSCP Value DSCP Name COS Value
0 Default (BF) 0
8 CS1 1
10 AF11 1
12 AF12 1
14 AF13 1
16 CS2 2
18 AF21 2
20 AF22 2
22 AF23 2
24 CS3 3
26 AF31 3
28 AF32 3
30 AF33 3
32 CS4 4
34 AF41 4
36 AF42 4
38 AF43 4
40 CS5 5
42   5
44   5
46 EF 5
48 CS6 6
56 CS7 7

Note: EF is matching DSCP=46; COS=5 is matching DSCP=40

AF Drop Level

RFC 2597 leavingcisco.com defines the assured forwarding (AF) PHB and describes it as a means for a provider DS domain to offer different levels of forwarding assurances for IP packets received from a customer DS domain. The Assured Forwarding PHB guarantees a certain amount of bandwidth to an AF class and allows access to extra bandwidth, if available. There are four AF classes, AF1x through AF4x. Within each class, there are three drop probabilities. Depending on a given network's policy, packets can be selected for a PHB based on required throughput, delay, jitter, loss or according to priority of access to network services.
Classes 1 to 4 are referred to as AF classes. The following table illustrates the DSCP coding for specifying the AF class with the probability. Bits DS5, DS4 and DS3 define the class; bits DS2 and DS1 specify the drop probability; bit DS0 is always zero.
Drop Class 1 Class 2 Class 3 Class 4
Low 001010
AF11
DSCP 10
010010
AF21
DSCP 18
011010
AF31
DSCP 26
100010
AF41
DSCP 34
Medium 001100
AF12
DSCP 12
010100
AF 22
DSCP 20
011100
AF32
DSCP 28
100100
AF42
DSCP 36
High 001110
AF13
DSCP 14
010110
AF23
DSCP 22
011110
AF33
DSCP 30
100110
AF43
DSCP 38 

Thursday, January 19, 2012

Avocent Cyclades ACS console server password reset or reset unit factory defaults

Avocent Cyclades ACS console server password reset or reset unit factory defaults

The Avocent Cycaldes ACS console servers are great little units that run Linux and even give you full root console access. The root password is “tslinux” by default, but if it has been changed then you can boot the unit into single user mode by supplying the argument “single” to the Linux kernel selection during the boot process (make sure you put a space between the existing Kernel parameters and “single”) which will drop you to a root prompt.
On my unit, this line comes up as right at the start of the boot process:
Linux/PPC load: root=/dev/ram ramdisk=0x0001F000
So you would type ” single” (remember the space!) to give you:
Linux/PPC load: root=/dev/ram ramdisk=0x0001F000 single
Then just hit enter and the unit will boot up into single user mode and give you the root prompt.
At this point, if you want to restore the entire unit to the factory default settings which will erase all of the configuration, then just run “defconf” and then reboot the unit.
If you want to keep the existing configuration intact but just reset the password then you can just use the traditional Linux passwd tool to edit /etc/passwd:
[root@(none) /]# passwd
New password:
Re-enter new password:
Password changed
[root@(none) /]# saveconf
Checking the configuration file list…
Compressing configuration files into /tmp/saving_config.tar.gz … done.
Saving configuration files to flash … done.
[root@(none) /]# reboot
[root@(none) /]# Restarting system.

 Original link : http://new.spheron1.co.uk/2010/11/06/avocent-cyclades-acs-console-server-password-reset-or-reset-unit-factory-defaults/