InterVLAN Routing Issue

[jeremiah.nelson]

Hello.  My lab setup is like this.

Computer(vlan12) -> Switch 1 (vlan 5 and 12) -> Switch 2 (vlan 5) -> Switch 3 (vlan 5)

This the physical setup of the devices in use.

I cannot get to VLAN 5 on switch 2 and 3 from my computer.  I can access vlan 5 on switch 1 from my computer.

The DG of Switch 3 is Switch 2 (vlan 5) and the the DG of Switch 2 is Switch 1 (vlan 5).  The DG of the computer is Switch 1 (vlan 12).

From switch 1 I can access switch 2 and 3.

Here is the output from "show ip route" on switch 1.  It has been edited for the relevant information.

C       10.223.7.0/24 is directly connected, Vlan5

C       10.223.8.0/23 is directly connected, Vlan12

Here are the settings for all the trunk ports between each switch.

switchport trunk encapsulation dot1q
switchport trunk allowed vlan 5,12
switchport mode trunk

Any ideas?  If you need any other information please let me know.  Thanks.

Jeremiah Nelson

[Antonio Knox]

Make sure that the native vlan matches across the trunks and also make sure that there is one VTP server and make the rest of the switches VTP clients.  That's where I'd start.

[Sebastian Helmer]

Hi Jeremiah,

I think it is a routing missunderstood, e.g. Switch 3 aks the DG Switch 2 but Switch 2 did not know the way to VLAN 12 in your case.

Try to set on SW 2 and 3 as DG SW1 and try again.

If you try from SW 1 to connect SW 2 & 3 the switch use always the interface vlan5 as source. If you want to test that first without changing the DG try it by extended Ping or Trace.

what kind of switche do you use? Just for the case that you want to go on with you setup..

regards,
Sebastian

[jeremiah.nelson]

@Sebastion

I am using 3750x as switches 2 and 3.  I am using a stack of 2-3750g switches as switch 1.

The DG of switch 2 is switch 1.  I am able to access switch 2 and 3 from switch 1 but not from the computer.

@Antonio

I tried with the native vlan matching on all 3 and still the same response.

Jeremiah Nelson

[Sebastian Helmer]

You said it's a lab, would you be so kind and post the config?

[jeremiah.nelson]

It is a lab but it is has the security information for my company on it as it will be put into production.  Is there specific information you would like?  I can post the parts of the config if you'd like.

Jeremiah Nelson

[Sebastian Helmer]

I know that just a DG is not enough on multilayer switches to "route"...

try to add a static route 0.0.0.0 0.0.0.0 10.223.7.X (default gateway IP) on Switch 2 and 3..

thats all in the moment, otherwise I had add the config to my lab and just try something but is ok if you have special config inside..

we find a solution in another way

[glen.grant]

   On the switches you are having trouble with make sure you have created the layer 2 vlans , check with the show vlan command.   If trying to ping pc's make sure all firewalls are off .  The default gateway  for  clients  should be whatever vlan 5 is defined on switch 1 .  Anything related to vlan 5 , the gateway should be the SVI address on switch 1  for vlan 5  as its doing the routing for everything in vlan 5.

[jeremiah.nelson]

@Sebastian

Isn't the DG and the ip route statement pointing towards the DG redundant?  I will give it a whirl though.  Sorry for having a super secret special config. 

If there are parts you need I'd be happy to post them.

@glen

When doing a show vlan on both switches it shows the vlans.  I am attempting to connect to the switches from the computer to configure them remotely.  There is nothing else attached to the switches.

Jeremiah Nelson

[Sebastian Helmer]

OK! got deep into me and review my post

Is there ip route enabled on Switch 2 and 3 if yes you need the route command, if not there is a nother problem I did not see in the moment..

VLAN settings should be ok because you can access all switches from switch 1.

[Sebastian Helmer · Accepted solution]

OK Guys I did a small easy lab to focus on that problem..

add the no ip routing command or add the ip route command i post...it will work..

post the "sh ip redirect" or "sh run I no ip routing", "sh interface trunk"..

regards,

sebastian

[jeremiah.nelson]

Worked like a charm.  Thank you very much for your assistance.

Jeremiah Nelson