Lecture Notes for Day1 Switching Lab

Layer 4 - segments - Ports TCP/UDP
Layer 3 - packets - IP Address v4 32 bits - Router/Switch
Layer 2 - frames - MAC Address 48bits - Switch
Layer 1 - bits / bytes - Hub


default VLAN
-------------
1
1002
1003
1004
1005

#show flash:vlan.dat


- 1-4094

- Normal VLAN Range (2-1001) >> can create in which VTP mode ? >> vtp server / transparnet mode
- Extended VLAN Range (1006-4094) >> can create in which VTP mode ? >> vtp transparent mode

- what is VTP ? ( show vtp status )
- VTP Mode ( Server, Client, Transparent )
- vTP Client Mode >> Cannot create VLAN, delete VLAN

- IOS ( lanbase, ipbase, ipservices )

- startup config vs running config

POST
-----
POST: CPU Buffer Tests : Begin
POST: CPU Buffer Tests : End, Status Passed
POST: CPU Interface Tests : Begin
POST: CPU Interface Tests : End, Status Passed
POST: Switch Core Tests : Begin
POST: Switch Core Tests : End, Status Passed
POST: CPU Interface 2nd Stage Tests : Begin
POST: CPU Interface 2nd Stage Tests : End, Status Passed
POST: CAM Subsystem Tests : Begin
POST: CAM Subsystem Tests : End, Status Passed
POST: Ethernet Controller Tests : Begin
POST: Ethernet Controller Tests : End, Status Passed
POST: Loopback Tests : Begin
POST: Loopback Tests : End, Status Passed

- Blocking ( 20 secs ) , Listening ( 15 secs ), Learning ( 15 secs )

- how switch learns MAC address

- show mac address table vs show ip arp/show
- layer 2 broadcast (ff:ff:ff:ff:ff:ff)
- layer 3 broadcast (255.255.255.255)

Switch#show arp
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  10.1.1.3                0   10dd.b1c8.3a21  ARPA   Vlan1
Internet  10.1.1.1                2   2cd4.44b7.6c6a  ARPA   Vlan1
Internet  10.1.1.254              -   000d.bc91.7f80  ARPA   Vlan1

- Creation of Interface VLAN ( so called SVI- Switched Virutal Interface )
- Why interface VLAN ?


Switch#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#ip routing
Switch(config)#end

Switch#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

C    192.168.10.0/24 is directly connected, Vlan1
     10.0.0.0/24 is subnetted, 1 subnets
C       10.1.1.0 is directly connected, Vlan20
Switch#


Scenario
---------
- set all the PCs with IP Addresses and point to their respective gateway
- do the ping test from each pc and analyze the result
- configure "no ip routing" , the ping will fail
- that proves the difference between Layer 2 Switch and Layer 3 switch

Commands
--------
show run
show ver
show vtp status
show vtp password
show etherchannel summary
show int trunk
show spanning-tree
show ip route
show vlan brief
.

VLAN Simplified

Here you go for my drawing of " VLAN Simplified " ...

STP Five Port States

Each L2 port on a switch running STP exists in one of the these five port states shown in the figure :

Let's take a look at TCN when we issue "debug spanning-tree events" ...

"switchport host" command

Cat1(config-if-range)#switchport host
switchport mode will be set to access
spanning-tree portfast will be enabled
channel group will be disabled

Cat1(config-if-range)#do sho run int f0/9
Building configuration...

Current configuration : 81 bytes
!
interface FastEthernet0/9
 switchport mode access
 spanning-tree portfast
end

Cat1(config-if-range)#

rapid-pvst (root primary/secondary)

spanning-tree vlan 100,200 root primary      = spanning-tree vlan 100,200 priority 24576
spanning-tree vlan 300,400 root secondary  = spanning-tree vlan 300,400 priority 28672

VTP Pruning

VTP Pruning will eliminate unnecessary broadcast traffic on trunk links.  If a broadcast comes from VLAN X, and the neighboring switch does not have any access ports in VLAN X, this broadcast will not be forwarded to it, even if the VLAN is allowed on the trunk.
NOTE that this does not prevent a Spanning-Tree instance from being created for the VLAN X on the neighboring switch.  If there is a desire to limit the spanning-tree instances on the neighboring switch, manually removing (or as many people call it manually "pruning") the VLAN from the trunk port is the only way to do this.
Reference : CCNP to CCIE RS Transition Kit by IPEXPERT

Verifying DTP Setting

Cat1 Fa0/23 is connected to Cat2 Fa0/23 ...

CDP Exercise

- Operates at Layer 2;
- Send out periodic advertisements to the MAC multicast address 0100.0ccc.cccc;
- every 60 seconds by default;
.

MST (802.1s) Labbing

Designated Port, Root Port & Blocking Port

After spending 8 hours, I've done my notes regarding about "Analyzing Designated Port, Root Port & Blocking Port". As usual, I draw nicely with full of colors.

SOLUTION - 1

-----------------

Cat2(config)#int f0/24

Cat2(config-if)#spanning-tree vlan 10 port-priority 48

Cat2(config-if)#end

SOLUTION - 2

------------------

Cat1(config)#int f0/24

Cat1(config-if)#spanning-tree vlan 10 cost 18

cat1(config-if)#end

Best Regards,

Sai Linn Thu

When "TRUNK" meets "ACCESS"

When ISL meets 802.1q ...

Spanning Tree Load Balancing

I was asked in one of the interviews about Spanning Tree Load Balancing. Initially, I don't get what the interviewer is trying to ask me. I was thinking after the interview, then I assume what he was trying to ask is as below ???

For example :

CORESWITCH01

--------------------

!

spanning-tree mode rapid-pvst

spanning-tree extend system-id

spanning-tree vlan 10,30,50,70 priority 16384

spanning-tree vlan 20,40,60,80 priority 8192

!

CORESWITCH02

--------------------

!

spanning-tree mode rapid-pvst

spanning-tree extend system-id

spanning-tree vlan 10,30,50,70 priority 8192

spanning-tree vlan 20,40,60,80 priority 16384

!

Packaging for Cisco IOS Switches

Reference : http://www.cisco.com/en/US/prod/collateral/iosswrel/ps8802/ps5460/prod_bulletin0900aecd80281b17.html

10/100/1000 Mbps ???

cat5 - 10/100 Mbps

cat5e - 10/100/1000 Mbps

cat6 - 10/100/1000 Mbps

Preparation for EtherChannel Interview Question

STP

The question I was asked in one of the interviews. According to given topology, you need to define RP, DP and those ports which are in Blocking. The best interview technique for STP I've ever seen.

VTP

If you get bored to read books, please go to this link
http://www.cisco.com/warp/public/473/vtp_flash/

Make sure native VLAN for dot1q trunk

I'm studying Switching Section since I back from Narbik's bootcamp. My study method, which is according to Narbik's recommendation, is Narbik's Workbook 2.0 and follow by DocCD for respective technology/section.
This post is nothing special but it comes to my mind for Open Ended Question Preparation.
"Make sure the native VLAN for an IEEE802.1Q trunk is the same on both ends of the trunk link. If the native VLAN on one end of the trunk is different from native VLAN on the other end, spanning-tree loops might result."

Will VTP password propagate via VTP messages?

This is a simple question. But, we can face these kind of simple questions in Open Ended Section of Lab exam. Undoubtedly, Handling and Interpreting questions is one of the vital skills to pass the CCIE Lab exam. So, when I read the concept of technology, I try to ask questions to myself of what and how the questions will come. And I believe that this habit makes me more clear and understandable of technology what I've read.
Let's back to the answer of that question! VTP password will not propagate via VTP messages. You can verify by checking Configuration Revision. Configuration Revision does not change when you change VTP password. And so, the VTP password must be configured statically on all switches.