Posts tagged cisco




Voilà comment faire une configuration Radius sous IOS XR dans une VRF


VTY access-class dans une VRF




Est-ce que vous avez aussi un problème pour mettre une access-list sur un accès SSH ou telnet d’un router qui se trouve dans une VRF ?





Comment faire alors ?

Il faut utiliser l’option vrf-also dans l’access-class in


Et voilà !




Cisco Tricks


Have an unsupported gbic module ?


Hot adding or removing a Cisco 3750 from a stack


When using a Cisco 3750 stack connected through stackwise technology you can add or remove a Cisco switch while the stack stays on. If you are adding or removing a switch from the stack, it is very important that the switch is turned OFF. The rest of the stack can keep doing its business.

For adding a switch to the stack follow these steps:

Step 1) On the new switch give the global command: switch stack-member-number provision type

Type is the type of switch you are adding to the stack.

When adding for example a third Cisco switch to the Cisco stack, use the following command:

switch 3 provision ws3750g-24t

Step 2) Power off the new stack member

Step 3) Connect the new member to the Cisco stack using the stacking cables, 1 loop at a time.

Step 4) Power on the new stack member. The switch will come alive and will receive the Cisco IOS version from the master, when that is completed it will be ready to service network requests.

For removing a member switch from the stack use the following steps:

Step 1) Power off the stack member to be removed.

Step 2) Remove the stackwise cable from the switch.

Step 3) Issue the following command on the stack master: no switch stack-member-number provisiontype

Cisco – Port mirroring


Voilà comment faire pour mirrorer un port:


Il est également possible de mirrorer un VLAN


Cisco IOS Tips and Tricks


Il est toujours utile de connaitre les raccourcis clavier. Cela permet d’aller plus vite 🙂


Keyboard Shortcuts

Voici celles que j’utilise le plus

Ctrl+A Move cursor to the beginning of the line
Ctrl+E Move cursor to the end of the line
Up Retrieve last command from history
Down Retrieve next command from history
Ctrl+W Erase previous word
Ctrl+U Erase the entire line
Ctrl+C Exit configuration mode
Ctrl+Z Apply the current command and exit configuration mode

Modifying output

On peut modifier la sortie d’un show à l’aide des commandes “begin, include, exclude et section”.


Il est aussi possible d’utiliser des expressions régulières dans les show

Cisco IOS – Google power


Google power search

By the “Power of Google”, you can do anything and averything you want:-).

Juste copy paste this command to find IOS

or just click below



Cisco feature set upgrade


Error: The image in the archive which would be used to upgrade Error: system number 1 does not support the same feature set.

Cisco it seems included this sanity check,as of 12.2(35), to prevent you from accidentally changing the feature set during a IOS upgrade, not a nice thing to happen on a production switch, when things go belly up.

You will get the above error when upgrading the IOS and changing the feature set. IE if you upgrade the image from IPBASE 12.2(35)SE5 to ADVIPSERVICESK9 12.2(25)SEE4.

So to bypass this, you can add the /allow-feature-upgrade parameter, to the archive download-sw command.

Example :

If you need more info on how to upgrade the IOS on a Cisco 3560, visit

Cisco – Spanning Tree


Identifying a Bridging Loop

Suspect a loop if you see the following:

  • You capture traffic on a link and see the same frames multiple times.
  • All users in a bridging domain have connectivity problems at the same time.
  • There is abnormally high port utilization.

To remedy a loop quickly, shut redundant ports and then enable them one at a time. Some switches enable debugging of STP to help in diagnosing problems. The following commands are useful for isolating a bridging loop


Spanning-Tree Best Practices

To optimize data flow in the network, design and configure Spanning Tree in the following ways:

  • Statically configure switches to be the primary and secondary root bridges by setting priority values.
  • Consider which interfaces will become designated and root ports (possibly set port priorities/path cost).
  • Tune STP using the tools detailed in this section.
  • Enable UDLD aggressive mode on all fiber interfaces.
  • Design STP domains that are as simple and contained as possible by using multilayer switches and routed links.
  • Use PVRST+ or MST for the fastest convergence times.
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