Renew Default Security Keyring Cisco UCS

Step 1: UCS-A# scope security

Step 2: UCS-A /security # scope keyring default

Step 3: UCS-A /security/keyring # set regenerate yes

Step 4: UCS-A /security/keyring # commit-buffer

Factory Reset Cisco UCS 4.1 CLI

 ####You must use the local admin account in order for the option to be listed.

####Login through SSH to the FI VIP (or the current primary FI).

####Next connect to the local management CLI then execute the rease conifig command.

FI-A#local-mgmt

FI-A(local-mgmt)erase configuration

All UCS configurations will be erased and system will reboot. Are you sure? (yes/no):yes

####Make sure to do the same process on the other FI if you have a secondary.

####The configurations will be erased and the FIs will reboot.

Configure Gateway of Last Resort

1. First, log into the switch you wish to configure.
2. Next, escalate up to Configure Terminal and then type the following:
    a. #conf t
    b.  #ip default-gateway 172.16.X.X
    c.  #end
    d.  #write
3. Next you can direct your traffic through this route if you wish, as a gateway of last resort:
    a. #ip route 0.0.0.0 0.0.0.0 172.16.X.X
    b. #end
    c. #write
4. Verify by typing in the following:
    a.  #show ip route
    b.  Then verify you see a gateway of last resort listed.


Reference:
https://www.cisco.com/c/en/us/support/docs/ip/routing-information-protocol-rip/16448-default.html

Changing VLAN Root Bridge ID on a Layer 3 Switch

1.    First, you will need to identify the VLAN you wish to change. With Cisco switches (not sure about others yet), you can change the root bridge ID for each VLAN individually. Warning! This may/will cause a re-convergence on the network. My lab environment noticed very little issues, but again just a home lab and a medium/large network this can take down your network as everything tries to readjust. Again, all of my SOPs/tips have been done in a home lab, always follow proper procedures before performing changes on your live/home network.
2.    Make sure you design/choose your switch you wish to be root carefully. Usually, you want your big/fast switches to be the root so you don’t have your traffic handicapped at a small/slow switch. It is all depending on how you wish to design it.
3.    Once you identify your VLAN, perform the following to change the priority:
    a.    #configure terminal
        i.    #spanning-tree vlan XXX priority 4096
            1.    Numbers start from 0 and increment in the number 4096 intervals. So example: 0, 4096, 8192, 12288 etc.
        ii.    #exit
    b.    #write
4.    Sometimes this is quick, sometimes this can take a little time for the switches to readjust. Just a few simple commands, but can make a huge difference on the speed of your network.

Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_53_se/configuration/guide/2960scg/swstp.html

Configuring LACP EtherChannel on Cisco Switches

1.    First, identify which two interfaces on both devices you will be binding together. Our example we will do TenGigabit 5 and 6 on a Cisco 4500, and Ethernets 7 and 8 on a Nexus 5K.
2.    Once you identified your ports you wish to link together, then you can log into each of the switches you will be working on.
3.    Once you are logged in, first, shut down the interfaces you wish connect. This is Cisco best practice since EtherChannel can cause spanning tree loops if done incorrectly..
    a.    4500 Switch Commands
        i.    #conf t
        ii.    #int range tenGigabit 1/5-6
        iii.    #shut
    b.    Nexus 5K Commands
        i.    #conf t
        ii.    #int ethernet 1/7-8
        iii.    #shut
4.    Now that the interfaces are shut down, we can now continue with the configuration. First, we will do the Nexus 5K
    a.    #conf t (if not already there)
    b.    # int port-channel channel-number
    c.    #description TEST-EtherChannel
    d.    #exit
    e.    # int Ethernet 1/7-8
    f.    #switchport mode trunk
    g.    #(optional) switchport trunk allowed vlan vlan-number
    h.    #channel-group 11 mode active(it will attach to a port channel if already created and matching, if no port channel has been created previously, it will create one for you)
    i.    #exit
5.    Next, we will set up the same thing on the Catalyst 4500X. here, we will just jump straight to the interfaces and set up port-channel directly in the :
    a.    #conf t
    b.    #int range TenGigabit 1/5-6
    c.    #description test-EtherChannel
    d.    #switchport mode trunk
    e.    #channel-group 11 mode active
6.    Your Cisco switches now should be configured and ready to start linking. The last step is to turn on the interfaces. Remember, we shut them down first in order to protect the systems from spanning tree loops. This is especially true when you use the hard coding EtherChannel, but we shut them down anyways for Cisco best practice. Now go into each Cisco switch, select the interfaces in the EtherChannel again, and then turn on the interfaces. The following are the steps:
    a.    Cisco 4500X Example
        i.    #conf t
        ii.    #int range TenGig 1/5-6
        iii.    #no shut
    b.    Cisco Nexus 5K
        i.    #conf t
        ii.    #int Ethernet 1/7-8
        iii.    #no shut
7.    If you noticed, the Cisco Nexus you do not have to select a range for the interfaces. You can just select them. With the Catalayst, you must put in the range in order to select them.
8.    You should start seeing the connections come up. You can do the following to see the status:
    a.    Cisco Nexus 5K: #show interface status
    b.    Cisco Catalyst 4500X: #show ip interface status
   
References:

Cisco Nexus 5K
https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/interfaces/6x/b_5500_Interfaces_Config_Guide_Release_6x/b_5500_Interfaces_Config_Guide_Release_602N12_chapter_011.html

Cisco Catalyst 4500X
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/3-1-1SG/configuration/guide/config/channel.pdf

Changing/Adding DHCP Relay Nexus 5K

1.    First, you want to verify the DHCP relays in the Nexus 5K with the following command:
    a.    #show ip DHCP relay
2.    Verify the relay address of the IP addresses.
3.    Escalate up to configuration terminal. Then select the interface/VLAN interface you wish to change the DHCP relay address for:
    a.    #conf t
    b.    #int vlan xxx
4.    Now you have the VLAN/interface selected. If the interface already has a DHCP relay, first, remove the old relay address with the no command:
    a.    #no ip dhcp relay address x.x.x.x
5.    Next, you can add the new DHCP relay address to the interface/VLAN:
    a.    #ip dhcp relay address x.x.x.x
6.    Finally, test your device to verify the systems on the network are receiving IPs.

Common and Basic Cisco Commands

Common and Basic Cisco Commands

This list is just a quick list of tips and commands that are only for my reference. These are just quick inputs and notes, and these are not considered a walkthrough. This list will constantly be updated over time and when I have time to update it.

·         You type in something wrong and get the “Translating “your incorrect entry” …domain server (255.255.255.255), you can stop this in the middle of it by the following:

o   Ctrl+Shift+6 will abort this process.

·         To prevent the Cisco device from trying to resolve an incorrect entry into an IP address, you can put in the following:

o   Escalate up to “configure terminal” mode

o   Enter the following command: #no ip domain-lookup

·         You can see the previous history of entered commands by typing in:

o   #show history

o   If you want to change the size of the history, perform the following:

§  Escalate to configure terminal level

§  Select console line by typing the following: #line console 0

§  Next type in #history size 50. You can put in any number from 0-256 for how many lines you want history to remember.

·         You can exit by doing Ctrl+Z or by typing #exit.

o   Typing #end will take you all the way back to the beginning of the Cisco device privilege modes.

·         You can see what is on the hard drive or flash of a Cisco device by typing in #show flash.

o   If you want to remove files on the flash, execute the following:

§  #delete flash:’filename’

§  Confirm the deletion.

o   Sometimes files can be deleted by the following command (if they are still stored and not being deleted) #squeeze flash.

·         One vital command which is helpful is the ability to reload the router through CLI. This is performed by typing the following command:

o   #reload in 5

o   This reboots the router in 5 minutes. You can have it reboot in any amount of time you designate.

o   This allows you to wipe the configuration if you have not already committed the changes and saved to the flash.

o   #reload cancel cancels the reboot.

·         #show running-config to show the current configurations which are running on the Cisco device.

·         #show startup-config to show the configurations which will be loaded into the Cisco device upon boot.

·         #copy running-config startup-config” will give you the option to save your current running configuration to the startup configuration fle.

o   #copy run startup-config and #write memory commands also save the configurations (can also just type write).

·         #write erase will allow you to erase your saved configurations in NVRAM and take you back to factory defaults.

·         To kick users from the device execute the following:

o   #show users

o   #clear line vty #

·         To show spanning-tree information for priorities, if an interface is blocked, designated, or the switch is root, and other information:
“show spanning-tree” will display the information.