topic Re: Overlapping vlans !??? in Switches, Hubs, and Modems

Overlapping vlans !???

victor_162 — Wed, 19 Oct 2005 04:52:07 GMT

Hello,

I have a problem with 2524 switch, a configuration problem, i need to make 2 vlans, one vlan 1 with port 1 to 12, and another one with 13 to 18 ports. and ports 19 to 24 are assigned in both vlans (1 & 2).

Its called overlapping vlans.
But when i put a computer in vlan 1 and another one on port 21 (witch is in both vlans 1 & 2) its work perfecly, i can ping it ! But when i put my first computer in the second vlan, i cant ping my second (who is on port 21).

i just need two vlans, with several ports who are in both vlans to put servers for example.

my config (port assignments)

Port DEFAULT_VLAN vlan3 vlan20
---- + ------------ ------------ ---------
1 | No Untagged No
2 | No Untagged No
3 | No Untagged No
4 | No Untagged No
5 | No Untagged No
6 | No Untagged No
7 | No Untagged No
8 | No Untagged No
9 | No Untagged No
10 | No Untagged No
11 | No Untagged No
12 | No Untagged No
13 | No No Untagged
14 | No No Untagged
15 | No No Untagged
16 | No No Untagged
17 | No No Untagged
18 | No No Untagged
19 | No Untagged Tagged
20 | No Untagged Tagged
21 | No Untagged Tagged
22 | No Untagged Tagged
23 | No Untagged Tagged
24 | No Untagged Tagged

Please help me.
thx.

Re: Overlapping vlans !???

Manfred Arndt — Wed, 19 Oct 2005 13:49:34 GMT

Hello Victor,

Simultaneous access to multiple VLANs
only works with Servers that support tagged VLAN packets and requires additional configuration.

You will need to configure the server with 802.1p tagging and assign the VLANs (For Intel this is under the PROSet Advanced tab).

Alternatively, you can install two Ethernet cards into the server, with one an untagged member of VLAN 3 and the other an untagged member of VLAN 20. This may also give you higher server throughput.

Cheers

Re: Overlapping vlans !???

Preston Gallwas — Tue, 25 Oct 2005 17:40:56 GMT

Victor, unless you have the advanced featureset of your NIC enabled, you wont be able to use VLAN's on servers. Its a bit of extra config. I've attached a screenshow of how my machine is set up.

I do NOT know of a way to do this without the vendor tools (Intel PROSET has it, as well as BROADCOM, etc)

You go in, right click the device, and "ADD VLAN"

You must add both VLANs, and can mark them as tagged or untagged in your configuration on the device