CRS - Trunk-Port with all VLANs including those, which are not configured

RouterOS General
1

Hi!

I want to replace some switches with CRS-switches.

Is there any possibility to setup “trunk-ports” wich always hold all VLANs and

  • where every new vlan is instantly available tagged
  • where every unknown vlan is forwarded to, that enters another trunk-port?

Dell switches e.g. handle VLANs on ports this way, if they are configured with:
switchport mode trunk

Thank you for your help
Stril

2

The answer might depend on which exactly CRS device are we talking? If we’re talking about CRS3xx, then the answer is likely: “can be, but not using single command”.

The reason being: VLANs on CRS3xx are configured like this:

/interface bridge vlan
add bridge=bridge vlan-ids=AAA-BBBB tagged=portA
add bridge=bridge vlan-ids=CCC tagged=portA untagged=portB

The problem is, that you can only have one command with combination of bridge= vlan-ids= … and if you configure it initially like this:

add bridge=bridge vlan-ids=1-4094 tagged=ether1

you can’t later on add an access port

/interface bridge vlan
add bridge=bridge vlan-ids=666 untagged=ether13
/interface bridge port
add bridge=bridge interface=ether13 ingress-filtering=yes pvid=666

as the combination bridge=bridge vlan-ids=666 overlaps the combination bridge=bridge vlan-ids=1-4094 already in use.


Essentially this way you can create a trunk with “wildcard” VLANs, you can even create a few such trunks and switch will forward “wildcard” VLANs between such interfaces, but you can’t add an access port later on (or a “non-wildcard” trunk port) … in that case, you’d have to drop all VLAN config and start to create smaller VLAN chunks to allow that one exceptional port.

3

Hi!

Yes, it’s about the CRS3xx models.

Thank you for your hints. That’s not, what I hoped, but maybe scriptable. It would be great to have an option to set a port to mode “contains all VLANs”.