Need help with bringing up a new switch

[Damon2021]

Hi,

I am bringing up a new L3 switch and I am missing something as the L3 vlan is not ping-able from internal network.

See diagram.

The core is existing and in production. I added a new L3 switch and would like to be able to ping 10.10.10.1 from internal network. I would like the ping to traverse the p2p link between switch and core (gi1/1). Please advice.

Thanks

[Flavio Miranda]

Hi

  10.10.10.1 is on L3 switch on the Core? 

check

show ip int br

make sure all vlan is up up.

According to your draw, looks like the network 10.10.10.0 is under the core and you created it again on the L3 switch.  If that is true, you are not going to ping.

[Damon2021]

10.10.10.1 is on the L3 switch only. The left side config block is for the L3 switch and right one is for the core.

Show ip int bri

on L3 switch shows up up for all vlans.

[Jon Marshall]

You don't need a network statement for 10.10.10.0 on the core switch if the subnet only exists on the new L3 switch. 

Jon

[Jon Marshall]

You can't route to the same subnet so either - 

1)  use a different IP subnet for management on new switch which would mean adding that subnet to the OSPF configuration on the new switch 

or 

2) add vlan 10 to the trunk link between the switches but if that is meant to be just routing between the switches you may not want to do that. 

Jon

[Damon2021]

What do you mean by "You can't route to the same subnet". Subnet 10 is only on L3 switch.

[Jon Marshall]

Yes, realised that after you responded. 

So adding vlan 10 to the trunk link would only work if you added the device you were pinging from to vlan 10 which I don't think you want to do so you may as well remove it.

What subnet is the device you are pinging from in because you need to add a network statement for that subnet to the core switch as I don't think your new switch has a route back. 

Jon

[Damon2021]

The core has many vlans and all are already advertised. I should be able to ping it from any subnet. The subnet I am using is already advertised and reachable from inside the network.

[MHM Cisco World]

core have vlan but new L3SW don't have any idea about subnet behind Core, 
either you advertise the VLAN subnet OR

default-inforamtion (0.0.0.0)

advertise from Core to new L3SW.

[MHM Cisco World]

there area you enter is 0.0.0.0 it not area 0 you need area 0
the trunk must allow also vlan 10

[Damon2021]

I updated the configs per recommendation but still no luck.

  - Changed area from 0.0.0.0 to area 0

  - Add vlan 10 to p2p trunk link

See update diagram:

[MHM Cisco World]

please see my above comment 

[MHM Cisco World · Accepted solution]

I think I found issue here, 
internal network is not advert via OSPF and here the New L3 SW don't know the subnet of internal users.
you need in OSPF to advert the internal users subnet or

default-information

in ospf of core do the job.

[Damon2021]

The existing core has other networks too in the ospf 1 and I wonder if adding this command will cause any issue with the existings.

[MHM Cisco World]

according to this config this good but 
in L3 SW do 

show ip route

 
do you see the internal subnet ??
if the OSPF not advertise the internal subnet and you can not config

 ospf default-information 

how new L3 SW know the internal subnet ??
this is the Q here.