Configure SNMPv3 on Cisco Router

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/configuration/xe-16/snmp-xe-16-book/nm-snmp-cfg-snmp-support.html

How to configure SNMP v3 on Cisco Switch, Router, ASA, Nexus (bestmonitoringtools.com)

Enter configuration mode

enable
conf t

Everything in bold you should look at changing.

snmp-server view ViewDefault iso include
snmp-server group GroupName v3 priv read ViewDefault
snmp-server location address
snmp-server user MyUsername GroupName v3 auth sha AuthPass1 priv aes 128 PrivPass

Exit and save changes

exit
write

Now we can verify the snmp details with

show snmp

Setup Remote Syslog on Cisco

Configure Logging

First we need to drop into configuration mode

conf t

Now we run the following command. Change ip-address to the address of you remote syslog server.

logging host ip-address

You will want to make sure that your time/timezone is correct.

https://community.cisco.com/t5/networking-knowledge-base/how-to-configure-logging-in-cisco-ios/ta-p/3132434

Set timezone

Change UTC and 0 to your your timezone and how many hours off UTC you are. For example for EST you would do EST -5

clock timezone UTC 0

Here are just the commands

terminal config
logging on
logging logserveraddress
clock timezone UTC 0
quit
wr

Cisco, Reload in X Minutes and Canceling

Cisco’s can be rebooted with the reload command. The reload command allows you to specify how many minutes like

reload 5

to reload in 5 minutes. We can also reload at a specific time. For instance

reload 13:30

will reload the router at 1:30PM.

For a Cisco config to remain permanent, we have to “write” i.e. save the config. By default, making changes, for instance an IP address on an interface, will get wiped on a reboot or reload.

We can take advantage of this behavior to “test” changes on a Cisco router.

Example:

  1. Run the command “reload 10” to reboot the router in 10 minutes. The plan is to cancel the reload after making sure our changes work
  2. Make the needed changes to the Router.
  3. After verifying that everything is working, run the “reload cancel” command to cancel the reload
  4. Now we can run “write” to save our new config

To recap reload 10 will reload a router in 10 minutes
If we loose access to the router while making changes, once 10 minutes has expired, the router will reload, returning it to the last know working state.
The reload cancel command will cancel the reload.
write will make our config persistent across reboots/reloads

https://superuser.com/questions/1080513/cisco-router-auto-restart-in-x-seconds

What is 802.11R (Fast Roaming, Fast Transition, FT PSK)

Fast BSS Transition is a method for a device to seamlessly move between Basic Service Set (BSS) AKA a Wireless AP’s, inside of an Extended Service Set (ESS) AKA, WLAN deployment.

This can help prevent Voip calls from dropping while someone is walking across campus or between buildings.

FT PSK is a Password option for Cisco equipment.

Some more resources for learning more.

https://evanmccann.net/blog/2021/11/unifi-advanced-wi-fi-settings

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/80211r-ft/b-80211r-dg.html

https://en.wikipedia.org/wiki/IEEE_802.11r-2008

What is Cisco VTY?

vty stands for Virtual Teletype. What is Teletype?

The teletype, or teleprinter, is a device used for communicating text over telegraph lines, public switched telephone network, Telex, radio, or satellite links.

Wikipedia explanation of teletype

https://en.wikipedia.org/wiki/Teleprinter

This means vty is essentially like a virtual computer screen plugged into the router that we can remotely access.

Both SSH and Telnet use this virtual monitor to let you see the router/switch.

The command

line vty 0 4

Configures 5 of these virtual teletypes (vty’s) for us to use. Can think of it having 5 monitors connected to the router. When you SSH to it, you are claiming one of these monitors. Cisco devices support up to a maximum of 16. 0-15

RSTP Alternative Port vs Backup Port

The following is some basic info on STP and RSTP. This list is not comprehensive. Refer to the link at the bottom of the page for more in depth details.

RSTP Priority

Default Priority is 32768 + VLAN ID

For example, if we are using vlan 10, then our default priority is 32768 + 10 = 32778

RSTP Priority can be set from 0 – 61440 in increments of 4096.

RSTP Port Roles

Ports can fill 1 of 4 roles.

Port RoleDescription
Root PortPort closest to the Root Bridge (Switches going to the Root switch)
Designated PortPorts going away from the Root Bridge (To clients)
Alternate PortA “backup” port for the Root port. If the Root Port fails, this port takes over
Backup PortEssentially a backup port for the designated port
RSTP Port Roles

RSTP Port States

A port can be in one of 3 states. Well technically 4 states if you include down/unplugged.

Port StateDescription
DiscardingPort discards packets (Alternate and Backup Ports)
LearningPort learns MACs and doesn’t forward data
ForwardingPort forwards data and learns MACs
RSTP Port States

RSTP Port Types

There are 3 port Types. Not to be confused with port States or Roles.

Port TypeDescription
Point to PointSwitch to Switch
Point to Point EdgeEdge of Network. Connected to a PC, Printer etc.
SharedHalf Duplex, Port connected to a Hub
STP/RSTP Port Types

RSTP Timers

There are three RSTP timers. STP has the same timers, but the MaxAge is 10 seconds, and the Forward Delay is used for both Learning and Listening states which takes a total of 30 seconds to complete.

Timer NameDefault ValueDescription
Hello Timer2 SecondsTime between Hellos created by Root
MaxAge6 Seconds (Hello Timer * 3)How long a Switch should wait before trying to readjust the network
Forward Delay15 SecondsDelay used for Learning/Listening in STP. Shouldn’t be necessary if legacy bridges are not used.
RSTP/STP Timers

Port Cost

There are technically two types of cost. The newer cost values were introduced so we could use faster ethernet speeds.

By default Cisco switches use the old cost values, but they can be changed to use the new ones.

spanning-tree pathcost method long
Ethernet SpeedOld CostNew Cost
10 Mbps1002,000,000
100 Mbps19200,000
1 Gbps420,000
10 Gbps22000
100 GbpsN/A200
1 TbpsN/A20
STP/RSTP Path Cost

More information can be found at the following link.

https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/24062-146.html