inter vlan access 1

[cooperchien]

I have a layer 3 switch 3550. I have enabled vlan 3 on interface 3 which connects to computer A and vlan 4 on interface 4 which connects to computer B. Inter vlan routing is working. computer A and B can ping each other.
Then I place a dummy switch on Vlan 3's interface. I connect computer A on that dummy switch.

Vlan 4's interface is still connecting to computer B.

Computer A and B cannot ping each other. Why?
Do I need to configure Vlan on the dummy switch? But that dummy switch is not a managed switch.....

 

[UnaBomber]

Is the Physical cabling ok?
Are you able to ping the default gateway?
What type of switch is the non-managed one, is it VLAN aware?

 

[vipergg]

Shouldn't matter if it is a non managed switch. Did you try clearing the arp and the mac tables while you doing this ?If you can ping between 3 and 4 with devices attached and you are just putting a switch into one of the ports it should work ok if you are sure it is a non managed switch. Do you have a link light on the non managed switch ? Do you have a link light on the 3550 when you connect the dummy switch? Start with the easy stuff , ping the default gateway of vlan 3 that is defined on the 3550. If it doesn't work then the dummy switch has a problem.

 

[cooperchien]

Here is the network diagram for my network.
I put a new Netgear switch that can configure Vlan on it. However, I have not done any Vlan configuration on it.

http://www.magicperson.com/VLAN_netgear1.gif

InterVlan communication is working on switch 3550. Computer 10.0.88.88 and computer 66.209.104.50 can ping each other. Computer 10.0.88.88 can ping computer 10.0.88.99. However, computer 66.209.104.50 cannot get ping-reply from 10.0.88.99. Why?

 

[vipergg]

Normally it should work if its in the default vlan , try setting the netgear in vlan 11 and see what happens . Make sure the link isn't in trunk mode , "show interface status" .

 

[UnaBomber]

InterVlan communication is working on switch 3550. Computer 10.0.88.88 and computer 66.209.104.50 can ping each other. Computer 10.0.88.88 can ping computer 10.0.88.99. However, computer 66.209.104.50 cannot get ping-reply from 10.0.88.99. Why

The reason why you can ping 10.0.88.88 --> 10.0.88.99 is because they are in the same subnet. 10.0.0.0/16

Without knowing your config, I presume you have layer 3 routing activated on the ints that 10.0.88.88 and 66.209.104.50 are on, thus you can route between subnets.

66.209.104.50 --> 10.0.88.99 has no uni-directional it seems because there is no route from 10.0.88.99 to 66.209.104.50.

What is the default gateway of 10.0.88.99? the pix or the int 10.0.88.1? (which by the way is in the same subnet as the pix)

vLAN taging will only happen when you enable a trunking protocol, such as 802.1q. A switch is aware of vLAN's through configuring of access-ports, a layer-3 device is able to route between subnets/vLAN's. a vLAN is just a logical representation of subnets, linked to ports on a switch.