Routing from SG200 to SG300

[Miscues15]

Hey All,

Bit of an issue I'm having at the moment.  Have an SG300 in my network, which works fine with multiple VLANS and routes working as expected.  I just introduced another SG200 into my network, which I know isn't layer three, to support some POE and other devices.

IP address of both switches are in the 172.16.15.x space.  If I plug into the switch and set my host to 172.16.15.x I can get to all assets in my environment and all assets on the Layer 3 (SG300) switch.  The problem is if I change my IP address to be in the subnet I desire, 172.16.20.x, plugged into the SG200 switch, I can't get to any assets plugged into the SG300.  I can't even ping the SG200 at that point which lives in the 172.16.15.x space.  

Can someone make sure I'm doing my VLAN/Trunking correctly, please?  Any help or recommendations would be greatly appreciated.  Essentially what I'm trying to do is have all of my assets regardless of IP or VLAN on the SG200 get trunked to the SG300 for routing.  Screenshots attached.

One other note.  If I'm on an network that's plugged into the SG300 device, I can't ping the SG200.

[pwwiddicombe]

Can we see the similar config on the SG200?  It should have the trunk and same vlans allowed.

[Miscues15]

Yes, sorry.  Meant to attach that as well.

[pwwiddicombe]

Vlan 1 is the 172.16.15.x and 20 is 172.16.20.x; and I'm guessing 10 is 172.16.10.x ? 

It looks like the 200 switch only has 2 ports in vlan 20; and the rest are all trunk ports ?

Some old-style " show run int ... " with a few of the key interfaces as well as the VLAN interfaces (or show run, shortened without ALL the interfaces listed)  might make it clearer to some of us older folk.

(The same on the 300 as well - quite possible something's missing there as well.  The "quick GUI view" seems to indicate ports are set up, but routing and VLAN definitions we can only guess at)

[Miscues15]

Will post that well.  But one of the odd things is, regardless of which port I'm plugged into on the SG200 (if I'm plugged into those Trunk ports for example) I still can't get to any assets on the SG300 when I change my IP address to 172.16.20.x.  I can however get to everything if I set my IP address to 172.16.15.x.  

When running Traceroute, I get no route to host when I'm set to a 172.16.20.x address.

[pwwiddicombe]

On the trunk port, you didn't specify switchport mode trunk/access, so it will negotiate; and the default vlan for an access port is 1, since your PC doesn't negotiate as a trunk port.  In vlan 1, the only IP address range that will work properly is the 172.16.15.x.

[Miscues15]

Here is the show run int g20 (trunk port) on the SG300.

switch36b0ff#show run int ge20

interface gigabitethernet20

switchport trunk allowed vlan add 10,20

!