Now that I have made it through all of the videos, now it is time to go through all the labs to force myself to remember the commands that were reviewed in the training.
As I know that I will not be able to remember all the commands, I am going to put some rules in place to make sure that I am forced to research the commands and not just read the commands and blindly enter them.
- I cannot use the lab Answers
- Have to use the CLI help first
- Google answer next step
- Read notes taken from videos on this blog
- Lab 11 – Device Function
- Verify interfaces
- show ip int brief
- Find MAC address
- show int [interface
- Verify connectivity
- ping [IP address]
- This works for the lab but depending on real life setup pings can be mis-leading as ICMP is not always allowed.
- ping [IP address]
- Show dynamically learned MAC address on switch between routers
- show mac-address-table
- Clear mac address table
- #clear mac-address-table
- Do you see MAC address after clearing, why or why not?
- If you do a show quickly the table will be clear, but it is populated quite quickly as the devices (routers) and constinatly talking which re-populates the table.
- Show routes
- show ip route
- Configure IP address on interface
- conf t
- int [interface]
- ip address [ip address] [subnet]
- no shutdown
- I tend to forget this one, I will have to make a mental note to turn it on.
- Configure static route
- conf t
- ip route [destination ip address range] [subnet] [default ip of next hop]
- Example – ip route 10.10.30.0 255.255.255.0 10.10.10.2
- Verify interfaces
- Lab 12 – Life of a Packet
- Configure DNS server
- conf t
- ip name-server [IP address]
- So after I have completed and tested that it worked I went through the answer guide to ensure that I hadn’t missed anything. They had the command ip domain-lookup.
- Doing some research I found that this was on be default but many people use the “no ip domain-lookup” command as if you mis-type a command the device will attepmt to reach out to DNS to try and resolve the mis-typed info.
- Another tip given here by Peter Paluch:https://community.cisco.com/t5/switching/no-ip-domain-lookup/td-p/2705168
- What could be considered a more proper way of doing things, however, is this: Have the DNS server configured using the ip name-server command, and at the same time, on all lines (con 0, aux 0, vty 0 15), deactivate the automatic action of telnetting into all “words” that look like hostnames
- I am not sure if this “transport perferred” command is not in Packet Tracer but did not show in my tests.
- So after I have completed and tested that it worked I went through the answer guide to ensure that I hadn’t missed anything. They had the command ip domain-lookup.
- View ARP cache
- show arp
- Configure DNS server
- Section 13 – Troubleshooting Methodology
- This lab didn’t have real right/wrong steps, but started with: Troubleshoot Connectivity to DNS Server
- Steps I took
- Ping DNS server, failed
- Pinged gateway, success
- Traceroute to DNS server, reached gateway but no other hops.
- Check gateway router with “ip int brief” found interface down
- performed “no shut” on interface and tested with ping, success
- Test ping to another device with name, failed unrecongnized host/address/protocol on IP address 10.10.10.1
- IP address in correct
- Added correct address
- Tried again and still when to same 10.10.10.1
- Removed 10.10.10.1
- Tried ping by name and reached 10.10.10.10
- Still did not work
- Checked DNS server and DNS service was off
- Turned on DNS server
- Test and had success
- Steps I took
- At first it bothered me to be tested on the DNS server being off but it is a great reminder that networks can be perfectly setup but services can make it appear that it is the network that not working correctly. I have found this many times while supporting the Symantec/Bluecoat ProxySG. You must look at all aspects of the network not just the devices that you are responsible for.
- This lab didn’t have real right/wrong steps, but started with: Troubleshoot Connectivity to DNS Server
- Lab 14 – Router and Switch Basics
- Router and Switch inital Configuration
- Change hostname
- conf t
- hostname [name]
- Set IP addres on interface
- conf t
- int [interface#]
- ip address [ip address] [subnet]
- no shut
- Set management IP on switch
- After trying to assign a interface an IP address, I had to look this one up as I was quite sure it was not vty line…
- So the first search took me to a Cisco fo dummies, kind of funny: https://www.dummies.com/programming/networking/cisco/cisco-networking-switch-management-interface-configuration/
- So the first thing that it reminded me, switch ports cannot have IP address assigned to them and that IP address needs to be assigned to VLAN
- conf t
- int vlan 1
- VLAN 1 is the default VLAN
- ip address [ip address] [subnet]
- -Tested ping from another and it did not work
- Did a show “do ip int brief” and found that I forgot the “no shut” command
- no shut
- Working
- After trying to assign a interface an IP address, I had to look this one up as I was quite sure it was not vty line…
- Default gateway
- ip default-gateway [ip address]
- Add description for interface
- conf t
- int [interface]
- descritption [text]
- I made the mistake of putting the description on the VLAN as that is what I had configured for the mgmt interface.
- Verify the speed of the interface
- show int [interface]
- Manually configure interface
- conf t
- int [interface]
- duplex full
- This brought the link down, set the duplex on the router that the interface was connected to to match and everything came back online
- speed [speed]
- What version of IOS on switch
- show version
- Change hostname
- CDP (Cisco Discovery Protocol) Configuration
- Verify neighbors
- show cdp neighbors
- Disable CDP to one router on switch
- (config-int)#no cdp enable
- Clear CDP cache
- This was a little of a cheat since the lab exercise gave me that answer in the steps
- (config)#no cdp run
- (config)#cdp run
- Verify neighbors
- Router and Switch inital Configuration
- Lab 15 – Device Management
- Factory Reset
- Display running config
- show run
- Factory reset router and reboot
- erase startup-config
- The lab had the command “write erase” which does the same thing.
- reload
- I had to google this one as I missed the command in help…
- erase startup-config
- Display running config
- Password Recovery
- Set enable secret password
- (config)#enable secret [password]
- Boot into the rommon prompt
- Another on the that I had to look up but on this page it talks about tftp server and the rommon:
- https://www.sysnettechsolutions.com/en/recover-cisco-router-ios-using-rommon-mode-in-cisco-packet-tracer/
- List of all the config-register codes: https://www.cisco.com/c/en/us/support/docs/routers/10000-series-routers/50421-config-register-use.html
- (config)#config-register 0x2100
- #reload
- The lab had a step doing a “copy run start” but I did not complete this as it was not asked for, will see if nessary to recover the password
- Also they used 0x2120 opposed to 0x2100 that I used.
- It appears that the 0 at the end is the important designator that causes the device to boot into ROMmon, but it appears that 2120 sets console speed to 19200 where I believe 2100 stays at 9600
- Another on the that I had to look up but on this page it talks about tftp server and the rommon:
- Ignore the startup-config when booting
- rommon > confreg 0x2142
- rommon > reset
- Exit wizard – copy start-config to running-config
- copy start run
- So when I was doing the lab I did “copy run start” which copied everything over and broke the lab and basically set the device back to factory default
- copy start run
- Remove password
- (config)#no enable secret
- Set the router to boot normally
- (config)#config-register 0x2102
- #copy run start
- #reload
- Set enable secret password
- Configuration Backup
- Backup running config to flash
- copy run flash:
- show flash
- Backup startup config to tftp
- copy start tftp:
- Enter IP of TFTP server
- Backup running config to flash
- IOS System Image Backup and Recovery
- Backup the IOS system images
- #copy flash: tftp
- Enter source filename
- Enter tftp address
- Enter destination filename wanted
- Delete system image and reload it.
- del [filename]
- confirm name
- confirm deletion
- copy tftp flash
- enter tftp address
- tftp file name
- name that it should be called when it is copied back to device.
- Made a mistake in reading insturctions, they didn’t want the file reloaded back out the device they wanted the device to be restarted.
- Backup the IOS system images
- The lab redirects you to an article to give you steps to restore the device instead of asking question that you need to know.
- Load file from tftp
- Set vaiables
- IP_ADDRESS=[device ip]
- IP_SUBNET_MASK=[device subnet]
- DEFAULT GATEWAY=[Gateway IP]
- For our lab there was no gateway since TFTP server was on the same subnet as device, so we used the IP address of the device.
- TFTP_SERVER=[TFTP IP]
- TFTP_DESTINATION=flash:
- TFTP_FILE=[file name]
- Set vaiables
- Start Download
- tftpdlnd
- Yes to continue.
- Unable to complete due to Packet Tracer limitations
- tftpdlnd
- Load file from tftp
- IOS Image Upgrade
- Verify device version
- #show version
- Use tftp to upgrade device
- copy tftp flash
- (config)#system boot [file name]
- #write mem
- reload
- Verify device version
- Factory Reset