Routing between C9500 to C3850

[BVarwig]

I know this question or series of questions has been asked and answered with other examples but I'd like to see based on my issue.

Location A - C9500 - IP address 10.207.15.58 255.255.255.0

Location B - C3850 - Unknown IP address (meeting with their IT guy soon)

Location C - IE-4010 - IP address 10.151.15.30 255.255.255.0

I need to be able to communicate from Location A to Location C and not sure what I need to do on my end to allow that to happen.

On the location A C9500 I have the interface dedicated to the Location B switch trunked with the associated vlans across both networks but from there I'm not sure the routing steps from A to B that need to occur. Let me know what other information is needed to solve this. Thanks

[David Ruess]

Hello,

If it's a L2 connection, you will need to make sure Location B is allowing the same VLANs on its trunks to location A and C.

If it's a L3 connection, you will need to implement routing with either static routes or a routing protocol. A routing protocol will require you peer with Location B and that may not be likely. So I'll give the example with static routes.

At location A you will need a static route to your Location C network pointing to Location B. You will also need a static route at your Location C device pointing to the network of Location A with a next hop of Location B.

The person at Location B needs static routes to point to Location A and Location C networks pointed towards their respective interfaces.

Hope that helps

-David

You will need

[BVarwig]

I believe location B is trunked properly because we got a call from their IT Engineer asking why the network was getting flooded with broadcasts. (a whole separate issue that's happening). 

The scenario is we are installing a new network and integrating into an existing. The new network is communicating within itself as it should. Just when we went to ping across to location C's switch we were deader than dead. I was just trying to figure out the solution on my own before getting their IT Engineer involved to tell me how dumb I am. I've been messing around on packet tracer with the setup and haven't been successful which is why I came here.

So in my instance at least with the knowledge I have.. would my route from Location A to C be 
Location A
10.151.15.0 255.255.255.0 SWITCH B HOP
Location C
10.271.15.0 255.255.255.0 SWITCH B HOP?

[David Ruess]

Just to clarify when you say trunked do you mean a L2 connection with VLANs or does the interface have an IP?

If so then the VLANs need to be added to all switches and allowed on all connecting ports.

If It's a L3 then your config looks correct in your last post. This also means Switch B needs routes to your networks as well so you may have to involve the engineer at that location.

[BVarwig]

Correct, trunked with VLANs. I have my packet tracer model if you would like to look at it?

[Devaa]

Below is the simple solution for you with just L2 and SVIs. If you need L3, you need multiple IP subnets, static or dynamic routing. 

Simply you can create a VLAN for management purposes. For Example, let's say VLAN 100 with 10.207.15.0/24 subnet. 

Location A - C9500 - VLAN 100 - IP address 10.207.15.58 255.255.255.0

Location B - C3850 - VLAN 100 - IP address 10.207.15.59 255.255.255.0

Location C - IE-4010 - VLAN 100 - IP address 10.207.15.60 255.255.255.0

In the switch:

! Create VLAN 100
vlan 100
 name MGMT
 exit

! In trunk link make sure all or vlan 100 is allowed
int XYZ
 switchport trunk encapsulation dot1q
 switchport mode trunk

! Create L3 SVI for VLAN 100
int vlan 100
 ip add 10.207.15.XX 255.255.255.0
 no shut