strange VLAN problem

macwhizard

i'm able to ping other hosts in different vlans on the same switch. : i've tried IP ROUTE command and ping stat became request time out, but after a reboot, IP ROUTE doesn't have any effect. Is this normal ?.

hectorjhrdz

you can't see them because they are in other networks!!!!!!

if you want to ping them from the same SW it would have a MSFC (layer 3 SW). To ping host from different VLANs you need to establish a trunk with a router and create Sub-interfaces on it, each one related with a vlan. Then perform routing issues

rakem

macwhizard wrote:

i'm able to ping other hosts in different vlans on the same switch. : i've tried IP ROUTE command and ping stat became request time out, but after a reboot, IP ROUTE doesn't have any effect. Is this normal ?.

if you can ping hosts from different VLANs on the same switch, and you dont have a lyer 3 device, then i dont think you have your VLANs set up properly because its not possible...

computerguy9355

Are you using a layer 3 switch ? if yes, then it is possible since it can perform layer 3 routing. But if it is a layer 2 device, unless you got router on a stick configured, its not possible.

macwhizard

i'm using layer 3 SW, 3550..... I haven't configured any trunk ports, just created a couple of vlans, plugged router ethernet and hosts to vlans, assigned ip's on routers.

the problem is, IP ROUTING works sometimes, so having a L 3 SW is of no use for labs.... i guess.

Danman32

L3 switch isn't covered on CCNA, except in passing.
Remember that switches don't normally route, so each VLAN has to be treated separately as if they were part of a different switch. You have to route somehow from one VLan to another, either through a trunk, or descrete connections from each VLan to the router(s). I sometimes I forget that, just as I forget routes back when configuring routes out.

macwhizard

The problem is, i'm not allowed to use any other switches.

When you create multiple vlan's on the same switch, to the hosts in a vlan, the switch acts like a total stranger to other vlan's, even though it knows (thus, does not pass any requests to other vlan's) and when you trunk vlan's spanning several switches, vlan's having same vlan id behaves like they're one switch(or connected together). Is that correct ?.

if, so, my switch should not allow / pass any requests to other vlans. But i'm able to ping

Router A, e0

---

>Switch (vlan 1, ports 1~4)
````````````````````````````(vlan 2, ports 5~9)<

---

Router B e0

Hosts 1,2,3

---

>vlan 1``````````vlan 2<

---

Hosts 4,5,6

serial ports shutdown, not using any protocols.

rossonieri#1

hello,

i think you wont be able to ping also - unless something strange happens :P
like accidently you have a route to other network.

cheers.

Danman32

What can you ping? Are you establishing trunking between Router A and the switch, or router B and the switch? Any intrinsic connection between router A and router B that might be causing pings to route, such as a route to the internet?