Cisco 3750X redundency setup Query

[avilt]

My current network setup is shown in the attached file which is not completely redundant.

I am replacing the current EOL switches with new one Cisco Catalyst 3750X for L3.

What is the way to implement redundency for L3 switches? Is it using 2 L3 switches in a stack? Do I need any SFP ports/cables between the 2 L3 switches, or just cascade enough?

[Leo Laohoo]

What is the way to implement redundency for L3 switches?

Each stack has two uplinks:  One to the primary 4006 and another to the secondary 4006.  Unfortunately, you can't use EtherChannel.  Both uplinks from the stack should not be from a single 3750X unit.

Is it using 2 L3 switches in a stack?

A minimum of two units of 3750X can perform a stack (or a mixture of 3750/3750G or 3750E).  Bear in mind that the entire stack should have the same IOS version and the same Feature Set or License set.

Do I need any SFP ports/cables between the 2 L3 switches, or just cascade enough?

Ok, now this I don't understand.  Can you elaborate further?

[avilt]

Please find attached the latest network diagram. Except one L2 switch (Floor 2) rest all switches are in the same floor in the close vicinity.

So I will use copper cables for uplinks between L3 and L2 switches in Floor-1.

To connect between one L2 switche in Floor-2 and L3 in Floor-1, what type of cable should I use? Is it MMF (multi mode fiber) or SMF (single mode fiber)?

Also, between two  L3 switches, I will use one as primary and another as backup to provide full redundency. So how should I connec these two L3 switches? Is it thru SFP ports or stack?

Thanks

[Leo Laohoo · Accepted solution]

To connect between one L2 switche in Floor-2 and L3 in Floor-1, what type of cable should I use? Is it MMF (multi mode fiber) or SMF (single mode fiber)?

It depends on what's been laid.  At this distance, multi-mode will suffice.

Also, between two  L3 switches, I will use one as primary and another as backup to provide full redundency. So how should I connec these two L3 switches? Is it thru SFP ports or stack?

Connect the two 3750X using the stacking cable.

[avilt]

Thank You,

So altogether I need just one SFP port on each L3 switch right?

[Leo Laohoo · Accepted solution]

You have three sets of switches:

1.  Floor 2
2.  Floor 1 Server VLAN
3.  Floor 1 Server Desktop VLAN.

If you are going to connect #1 to your new 3750X via fibre then you need at least 2 SFP on Floor 2 side and another 2 on the 3750X side.

If I understood your description #2 and #3 will be connected using copper.  To ensure you have GigabitEthernet connectivity make sure you use a Cat6 end-to-end.

[avilt]

One question on routing part.

We have 2 routers running OSPF(as shown in the previous diagram). One router will be connected to Primary L3 switch and another router to Secondary L3 switch. In this case is the Primary L3 switch going to use both router links?

I would like to use both routers for WAN traffic. Appreciate your feedback.

[Leo Laohoo]

Secondary L3 switch. In this case is the Primary L3 switch going to use both router links?

Why?  If your core switch is going to be stacked 3750X you have stack member 1 connected to router 1 and stack member 2 connected to router 2.

[avilt]

In my current setup, I have only one L3 switch and both routers are connected to the same L3 switch

In my future setup as I am going to use two L3 switches, can I use both WAN links with one router connected to stack member 1 and another to stack member 2 ?

I am new to this kind of setup. Please ellaborate.

[Leo Laohoo]

In my future setup as I am going to use two L3 switches,

If you mean two 3750X then, as in my previous post, stack the two together to form ONE logical unit to maximize redundancy through simpler configuration:  You configure both of them as a single unit rather than configuring them TWICE.

can I use both WAN links with one router connected to stack member 1 and another to stack member 2 ?

Of course you can.  I highly recommend it.