core routing

[Liam Dwyer]

this is probably an easy one to solve but at the moment it is not getting past my brain...

I have a P2P network set up to another building. that building is being collapsed and I want to bring that subnet back to my core switch.  

I have two stacked core switches one for each side of my building and 2960 switches doing all the desktop work.

I added a new vlan to the core switch as well as the vlan interface and added the gateway for the collapsed building pool to the vlan interface.  I then added the switch ports to that vlan.  

I am not getting the correct DHCP address when plugging in.

thoughts?

[Aaron Harrison]

Post up your config.

You've probably got the second building uplinked to an access port in the wrong VLAN, or some of trunking misconfig.

Aaron

[Liam Dwyer]

attaching the config of the second stack in the building where I am having the trouble.

vlan 160 is what I want them on and 10.100.x.x is where they should be pointing.

[Aaron Harrison]

Hi

So 10.100.x.x is on VLAN 160.

All your access ports on this switch have a default access VLAN - which is 1.

You'd presumably want  them to have 'switchport access vlan 160'.

You've not posted your core - have you added a VLAN 160 interface there as well? If so, does it also have the 10.100.0.1 IP? that would be a conflict...

Aaron

[Liam Dwyer]

Correct so I have the two core stacks then a 2960 doing all port access and uplinking to the 3850's.  

I am only testing on one port currently so g48 is pointed to vlan 160.

attached is the main core.

[Jon Marshall]

Liam

Looking at your configs I think all the routing for vlans is done the core in building1.

If you look at the building2 core switch config "ip routing" has not been enabled.

I suspect you have created vlan 160 on the wrong switch ie. you need to create the L3 interface (SVI) for vlan 160 on the main core switch and make sure that the trunk connection from the other core switch is allowing vlan 160.

I may have misunderstood what you are trying to do though.

Jon

[Liam Dwyer]

Jon, 

no, your assumption is correct but it was my assumption that that tengig trunk would allow all vlan even though it is not explicitly stated in the port config.

thanks!

[Jon Marshall · Accepted solution]

Liam

The trunk will allow all vlans if you haven't explicitly said which ones are allowed so that bit should be fine.

I think you just need to move the SVI for vlan 160 to the main core switch.

Jon

[Liam Dwyer]

sorry. meant to add that part.  I did move the SVI to the main core. I have to go test the port that is configured.  back soon.

thanks again

[Liam Dwyer]

Jon/Aaron, 

looks as though I was just a little backwards as I am all set!

thanks again for all the help!

Liam

[Liam Dwyer]

hey guys, 

is there anything on that config that would limit the bandwidth to that vlan?

I am not getting full throughput on that vlan and they are getting crushed.

thanks

[Liam Dwyer]

Hey Jon, should the int vlan160 be programmed all both cores and the desktop switch or just the main core?

thanks

[Jon Marshall]

Liam

As far as I can tell only the main core is actually routing between vlans so you only need an SVI for vlan 160 on that switch stack.

You don't need it and probably don't want it on the other core.

Jon

[Liam Dwyer]

thanks at one point this was working great then something happened and some people are unable to get a DHCP address.  I have removed everything relating to an int vlan160 in any other switch than the main core.  
 

All desktop ports are set to vlan 160.  it is very odd.

[Jon Marshall]

So clients could get an IP but now they can't ?

Is it specific to one switch ie. one of the client switches or is it spread across multiple switches ?

Jon