Routing help

[richbrowncardiff]

Hi All,

 

quick question on routing...

 

I have an edge router 8-pro so far setup (working well)

Eth0 Lan 192.168.1.1/22 gateway 192.168.1.1

 

several vlans setup on this interface

 

we will say vlan 20 = 192.168.16.1/21, vlan 21 = 192.168.24.1/21 vlan 30 - 192.168.4.1/23 and vlan 40 = 192.168.6.1/23 etc

 

eth 7 out to Internet router

 

what I would like to do is move the vlans from Eth0 to their own physical interfaces to improve performance.

 

when I do this I can ping each gateway fine but clients don't get their ip addresses from dhcp.

 

the dhcp relay is set on eth0 then on each of the vlans such as eth0, eth0.20, eth0.21 etc

 

The default route is 0.0.0.0/0 next hop wan ip.

 

i'm obviously missing something when I change vlans to individual interfaces but can't see where I'm going wrong any ideas ?

 

Many thanks

[FN-GM]

Just to confirm, the issue is they don't get a DHCP address when you move the VLAN onto a physical port?

 

You need to put the DHCP Helper / Relay onto the new physical port.

[richbrowncardiff]

Thanks yes thats right. I did but thinking about it now now you've said it I guess I need to add the helper to all ports not just the perceived "incoming" port. Doh ! thanks will give it a go sure it will work then.

[FN-GM]

The easy rule is, the helper sits on the same interface (virtual or physical) as the IP address on the VALN (same IP that is used as the default gateway of VLAN).

 

Above you have it on eth0.20, the virtual interface. So that same logic applies when you have it on a physical interface.

Edited October 29, 2017 by FN-GM

[richbrowncardiff]

@FN-GM Many thanks for your help not working yet though.

 

Do I need to add an additional static route so the interface "see" each other ? I can see traffic on the interfaces but they dont get dhcp. Its really strange as traffic is passing and with the stacked approach all is ok but when I separate them out it stops working. I must be missing something

[FN-GM]

If traffic is passing when using a static IP it won't be the routing

 

Where did you put the IP Helper?

[richbrowncardiff]

The IP helper has been on both (tried both) physical and virtual,

Just so i'm clear so if i connect eth2 give it the gateway IP same as vlan now and put vlan ID onto the physical port with no ip on the vlan then put the helper on the physical interface it should work?

[ReBoot]

So Eth0 was originally a trunked VLAN interface and traffic from the VLANS then passed untagged onto Eth7 to your gateway.

 

What was connected to the other end of the VLAN trunk on Eth0 and how has it been reconfigured to put the traffic onto the new separate physical interfaces ?

 

Do you still need VLAN IDs on the new physical interfaces on the Edge Router 8-pro I would have thought it simpler to make these interfaces untagged.

 

It would be really helpful to have a diagram of your network. If the helper was working for the trunked interface it should work on the new physical ports provided it is configured on each port. I suspect something may be wrong with you basic setup of VLANs and trunking.