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VLAN switch problem

Posted: Mon Jan 14, 2008 6:14 pm
by LatinSuD
I have a routeros with 2 lan ports: users and internet gateways. I'd like to have more ports to monitor and control all internet gateways independently.

I have a SMC 8024L2 VLAN switch and I try to set it up like this, but it seems not to work:
- Gateways go on untagged vlan ports (vlan2, vlan3, vlan4...).
- Routeros go on a tagged vlan port that belongs to all vlans (vlan2, vlan3, vlan4...).

The problem seems to be that routeros uses a single mac address for all vlan addresses, and for the switch a mac address can belong only to one vlan.
Is it possible to assign a different mac address to a vlan interface (i think it can be done in linux)?
Or have multiple mac addresses per ethernet interface?

Re: VLAN switch problem

Posted: Tue Jan 15, 2008 2:24 am
by Chupaka
I do not have such troubles even with D-Link 1226G switches. Look at switch settings - maybe there is too big security in MAC area =)

Re: VLAN switch problem

Posted: Tue Jan 15, 2008 6:11 am
by dankerr
On a Cisco or a Dell you'd need to put the switch port in trunk mode. You may also need to enable vlan sharing. The commands are different on each (sometimes from model to model); but I'm sure the SMC needs a similar configuration. On older SMC and Netgear switches I've worked on it was very close to to Cisco; so it'd be something like ""interface name" switchport mode trunk" from configure mode. The vlan command is similar; but I don't remember the exact syntax though I don't think you need it unless you want to limit which vlans are trunked.

On one Dell switch (I think a 6224) we also needed to put vlan1 on the RouterOS interface for the switch to see the other vlans. After a later firmware upgrade on the switch to fix a different issue we didn't need to do this.

Re: VLAN switch problem

Posted: Wed Jan 16, 2008 12:55 pm
by Diganet
I have a routeros with 2 lan ports: users and internet gateways. I'd like to have more ports to monitor and control all internet gateways independently.

I have a SMC 8024L2 VLAN switch and I try to set it up like this, but it seems not to work:
- Gateways go on untagged vlan ports (vlan2, vlan3, vlan4...).
- Routeros go on a tagged vlan port that belongs to all vlans (vlan2, vlan3, vlan4...).

The problem seems to be that routeros uses a single mac address for all vlan addresses, and for the switch a mac address can belong only to one vlan.
Is it possible to assign a different mac address to a vlan interface (i think it can be done in linux)?
Or have multiple mac addresses per ethernet interface?
You create the different VLANs you need on the MT. You give those interfaces a different IP/Subnet like (10.0.1.1/24, 10.0.2.1/24 etc.)
Set up a DHCP server on each VLAN. Then you attach the VLANS to one ethernet port (trunk).

On the switch you create the same VLAN tags on the trunk port. Then you assign the ports on the switch as untagged ports, so that port 1 belongs to VLAN 1, port 2 belongs to VLAN 2 etc. After this is done you should be able to put a PC in any port, get an IP address in the right subnet and control each subnet (VLAN) as you wish. You can also set up rules so that the different subnets can't see each other.

Regards

/Henrik