need suggestion

[sateeshk10]

Hi,

Planning to have routed access layer. need sample configuration for access switch and distra.

Vlan 10 – subnet advertised by all the switches, how traffic flow will be for specific server.

Example: For vlan 10 best path from distra to access is access switch 1, but it supposed to reach server connected to second pair switch

please give me the sample configuration for vlan and distra-access.

Please refer the diagram for further information.

Regards

Kumar

[Jon Marshall]

You cannot do what you are proposing in your diagram.

If you want to use L3 in the access layer then you cannot have the same vlan or more specifically the same IP subnet on multiple access switches.

So if vlan 10 is using the same IP subnet on both access switches it won't work (same applies to vlan 20 as well).

Jon

[sateeshk10]

Thanks jon,  even i got a same thing in my mind but may i am wrong so, i thought to check in forum.

If you have any suggestions on  how to achieve in routed access layer the same setup please let me know ( i am fine with static routes on access layer rather than dynamic).

One more going to have a TWO vlans only in access layer, but there are multiple pairs (One for VLAN 10 and other VLAN 20).

Regards

Kumar

[Jon Marshall · Accepted solution]

You can only make this work if each access switch uses a different vlan/IP subnet.

The problem is not with OSPF or static routes, it is that you cannot route within an IP subnet and you would need to able to do this for your design to work.

There are specific technologies that can be used to extend vlans across a L3 network but these are mainly DC or WAN technologies.

Jon

[sateeshk10]

Yes, i do agree jon.

Regards

kumar

[Julio E. Moisa]

Hi

I agree with Jon, a good practice is use layer 2 links between access switches to distribution or collapsed devices. 

My 2 cents.

:-)

[sateeshk10]

Jon,

Deicded to have one subnet per rack on access switches but i want to use static routes on accsw instead of having dynamic..

But i want to have a two default routes in access switch pointing to distribution-A and distribution-B..do i need enable load balancing command ? 

how the configuration looks like?

Regards

Kumar

[Jon Marshall]

The access switch should automatically use both routes on a per destination IP basis so there is nothing extra you should need to do.

Jon

[sateeshk10]

Can i have link between distribution switches if so, what are the pros and cons.

Because some of the design docs suggesting to have link and some are not.

Regards

Kumar

[Jon Marshall]

Can you provide a link to a doc where there is no link between distribution switches because I have not seen that before. 

You usually want a link whether L2 or L3. 

Jon