can host insame subnet with different vlans to ping others witout router ?

[Dr.X]

hi ,

ihave a question ,

basic onfigure below ,

can hosts ping others ??

regards

[Raju Sekharan]

Yes. hosts can ping each other

Raju

[nspasov]

Yes, they can definitely ping each other. Now switch that port between the two switches to a trunk, then they will not as their packets will be vlan tagged.

[Dr.X]

hi ,

i mean relative to the figure above !!!!

there is not trunkl between the switches

please clarify how ?!!!

i thought they cant , because they are in different vlans ??

!!!!!

waiting ur clarify

regards

[AudiAthree_2]

did u assign vlan 5/vlan 2 IP addresses?

[Dr.X]

just based on the config   ,  can hosts ping others ?

[milan.kulik]

Hi,

yes, they can!

No VLAN assignment info is sent on access ports.

BR,

Milan

[Dr.X]

CAN YOU EXPLAIN WHY ???

do you mean traffic untagged ??

plz clarify

regards

[AudiAthree_2]

the originating port(Host) and the access port to the next switch, must belong to the same Vlan.  The ports that interconnect between the switches can be different or the same vlan

[milan.kulik]

Yes, exactly.

BR,

Milan

[Dr.X]

im sorry , i must be missunderstanding something.

can any one clarify how the traffic will be carried ???

i read that  hosts must be in same vlan so that they can communicate with others without router .

regards

[milan.kulik · Accepted solution]

Hi,

"So when Switch B recieved it it broadcast this packet to all the ports irrespective of vlan and the destination machine will acknowledge the packet."

This is not correct!

When switch B receives a frame on its access port, it looks to the destination MAC address field. Then it tries to find the same MAC address within its MAC forwarding  table for the VLAN to which that access port belongs. If found, the switch will send the frame only to the port with the destination MAC address assigned. If not found, the switch will broadcast the frame as an "uknown destination" to all ports (except the receiving one) within the VLAN. (The same behaviour is in a broadcast destination MAC address case.)

In any case, only the VLAN to which the receiving access port belongs is effected on switch B.

BR,

Milan

[InayathUlla Sharieff]

Yes you are correct ; sorry I didnt elebarate too much on this.

I forgot to mentioned about the unknown destination.

"Kindly let me know if you have my previous update as by mistake it is been deleted.

Thanks and have a nice day.

Regards

Inayath.

[milan.kulik]

Hi Inayath,

yes, I've got your previous update in my mail.

It was:

"

Hi CSCO,

You have the answer above. Anyway let me try to explain you:

In your scenario you have two switches: Switch A----- Switch B & they are connected through Access port.

( NOTE: Access port doesnt carry vlan information accross the switches.)

So when you have the same network across different vlan between switches you will be able to ping each other.

Eg:
Packets comes on F0/1 with IP address, Src mac and vlan info when it exist out of Port G1/0 the vlan information will be removed hence you will left out with the ip address , src mac, destination ip. So when Switch B recieved it it broadcast this packet to all the ports irrespective of vlan and the destination machine will acknowledge the packet.

NOTE: The scenario will change when you connect the switches using Trunk port or using different network.

To understand the packet flow do this on GNS or Packet tracer and capture the packet then you will be able to understand what will be inside the packet when it leaves the switch ports.

hope this helps. Let me know if this clarifies your doubt.

Regards
Inayath
* Plz rate if this helpfull'
"

BR,

Milan

[Dr.X]

hi , i would like to thank u all ,

thanks milan .

i nailed it down and understood it from ur example .

the best thing is to begin step by step how the switch deal with frames and i got it

with my best regards

Ahmad