Cisco Switches

How many buildings in your office and how many floors per office?

In general per design,

Every office building should have Layer3 switch and floors on the same building floors are connected thru L2 switch.

between office you can connect via fiber and connect L3 switches via dynamic routing protocol


Like below

Site 1

L3 switch ---> trunk port) ---> L2 switches --- different vlan users

site 1 Layer3 switch ---> fiber cable --- site 2 Layer 3 switch

#1 L3 switch ---> trunk port) ---> L2 switches --- different vlan users

In case each floor represent 1 VLAN (VLAN5 = Floor 5, VLAN16 = Floor 16), do I mean to create trunk port on L2 switches ?  I suppose I only need to create corresponding vlan port on L3 switch, any packet leaving and come in VLAN2 port will be tagged, correct?

eg. L3 switch (vlan 2 port)  <--> L2 switch (nothing configured)

#2 In case there one of the floor need to create with 2 VLANs, is my design below correct or not ? Do I need to enable routing protocol on both switch ?
L3 switch (trunk port)  <--> L3 switch (trunk port) --- (VLAN 2, 3..)

#3 When do I need routing protocol ? In case each floor is linked up by fibre, do I need routing protocol ? Tks

#1 In case each floor represent 1 VLAN (VLAN5 = Floor 5, VLAN16 = Floor 16), do I mean to create trunk port on L2 switches ?  I suppose I only need to create corresponding vlan port on L3 switch, any packet leaving and come in VLAN2 port will be tagged, correct?

Ans :-  

If you have only one vlan per floor, then you no need to configure trunk interface between L3 switch and L2 switch.

Like L3 switch -- vlan x --- L2 switch

At the same time, if you would like to have many vlan's per floor, then you need to configure trunk interface between L3 switch and L2 switch to pass all vlan's

// I suppose I only need to create corresponding vlan port on L3 switch, any packet leaving and come in VLAN2 port will be tagged, correct? //   -  Right

Pls refresh for my latest comment, Tks

#2 In case there one of the floor need to create with 2 VLANs, is my design below correct or not ? Do I need to enable routing protocol on both switch ?
L3 switch (trunk port)  <--> L3 switch (trunk port) --- (VLAN 2, 3..)

Ans:This is not a good design..  Both 2 Vlan's L3 will be configured in the L3 switch.  configure L2 vlans on the floor switch and configure trunk between L3 switch and L2 switch.

Sample config

L3 switch

conf t
vlan 10
name 10_Floor_sales

vlan 11
name 10_Floor_Support

int vlan 10
ip address 10.10.10.1 255.255.255.0
no sh

int vlan 11
ip address 11.11.11.1 255.255.255.0

int gi0/0
desc connecting to 10th Floor L2 switch
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk alowed vlan 10,11

10th Floor L2 switch

conf t

vlan 10
name 10_Floor_sales

vlan 11
name 10_Floor_Support

int gi0/0
desc connecting to L3 switch Main
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk alowed vlan 10,11


#3 When do I need routing protocol ? In case each floor is linked up by fibre, do I need routing protocol

If you have many buildings / many sites then you need a routing protocol to interconnect the sites.

within the same building, you no need to have routing protocol

Tks.

#1 For the other site, why not just configure it as VLAN (similar to than in the same building) to simplify the configuration.

#2 To increase the throughput between different floors in the same building, I'm thinking of configure 2 tunnel port. Can it make use of these port for data transfer ? Or should I configure lcap on these two port ? Alternatively, would it be more easy to configure fibre between each floor to link up the switches ?

Thanks again

#1 For the other site, why not just configure it as VLAN (similar to than in the same building) to simplify the configuration.

Ans:- Let me explain you the methods of connecting two offices are located in different region/location.

i)connecting the two sites via MPLS provided by third party service provider ( like AT&T/Verizon/Singtel/ etc); In this case you cant use the VLAN extension method because of the MPLS design.

Most of the companies(99%) used this design as its well known/well working design to connect offices

ii) connecting two sites via VPLS; Here you can extend the VLAN from one site to another sites. But mostly this design will be used for Datacenter to DR site


#2 To increase the throughput between different floors in the same building, I'm thinking of configure 2 tunnel port. Can it make use of these port for data transfer ? Or should I configure lcap on these two port ? Alternatively, would it be more easy to configure fibre between each floor to link up the switches

Ans:  If you would like to increase the link capacity between the floors on the same building, use etherchannel( either LACP or PAGP);

For point #1(ii), does it use MetroE to connect two site. In this case, I can create a trunk link to connect the switch from one site to another, similar to that in the same building, correct ?

#2 In case of bandwidth concern between different floor, should it be easier to use fiber rather than grouping few ports for etherchannel, any comment ?

Thanks.

Tks