I have to configure multiple vlans served with a unique DCHP server . As first step, I just will The DHCP server to serve 2 vlans. The following is the hardware and configuration that I implemented :
Router (RV016 10/100 16-Port VPN Router) as gateway mode:
IP : 172.16.0.1/24
DHCP Server :
IP : 172.16.0.2/24 GW: 172.16.0.1
2 subnets :
172.16.1.0/24 GW: 172.16.1.1 to serve vlan 1
172.16.2.0/24 GW:172.16.2.1 to serve vlan 2
Switch (SG 300-10MP 10-Port Gigabit PoE Managed Switch) as layer 3 mode:
IP 172.16.0.254 (vlan 8 default)
Vlan 1 : 172.16.1.1
Vlan 2 : 172.16.2.1
1 device connected on each vlan
a workstation on the vlan 1
a laptop on the vlan 2
In this scenario (see the attached pdf file) the DHCP server is connected on a router, hosts on vlans dont receive any IP address.
But If I connect the DHCP server on a trunked switch port and adapt the DHCP server gateway 172.16.0.1 to 172.16.0.254, hosts receive ip address properly.
I have to connect the DHCP server directly to the router. How can I do that, what is wrong in the configuration ?
I hope the explanations are clear enough and my English too
Any help will be highly appreciated,
A couple observations. I do not see any mention of multiple subnet configuration on the RV016. I also do not see mention of the DHCP relay configured on the router.
Additionally, I am assuming VLAN 8 internet works fine but VLAN 1 and 2 internet does not work?
Hello Tom, thank you for your reply.
Multiple subnet option is enabled and configured on the RV016:
It is also configured on the sg 300-10 MP globaly and on each vlan interface.
DHCP relay is also configured on the RV016.
Indeed, Vlan 8 internet works but only if I set a static IP manually on the workstation otherwise no ip is received from DHCP server.
Vlan 1 and 2 clients dont receive any IP and of course no Internet connectivity even If I configure the adresses manualy.
Try adding a couple static routes on the router.
hop count 1
hop count 1
Also check to see if the port on the switch is configured with 8u,1t,2t.
I did what you asked me but unfortunately with no result.
Is It really true that the RV016 does not support the 802.1q protocol ? That'is why maybe it does'nt work, isn'it ?
This is correct, it does not support 802.1q.
However, since the SX300 is L3, static route on the router can address the problem.
The issue you're experiencing is the concept, the default vlan, 8 can go to and from the router. The additional vlans 1 and 2, they will leave the switch but once they go to the router, the router has no path back to assign the traffic correctly. Therefore it simply drops.
Yesss, I got it ! You are right Tom. Static route on the router can address the problem and indeed it does it. Each host now receives its ip address that correspond to the vlan it belongs to.
This is the change I did :
That's all !
However there is a problem : hosts don't have internet connectivity although they receive the dns ip address (the same that DC, DHCP server). I have internet connection on the server.
Maybe, what you have to know is the next hop after the rv016 is not the ISP router but an intermediate router and I can't directly connect the rv016 to the isp router due to the fact that it is located in a datacenter on another floor of the building.
So what do you think prevents internet connection on the hosts ?
Thank you for you advices,
Zoubeir, the internet connection applies the same concept. Devices connecting on the switch send traffic, but when the router receives, it does not know how to send it back to the different LAN subnets. The static routes should address both issues
The router is 192.168.2.254. My computer connects to fa2. My router can connect to any other port. I also tested behind the double nat but it gave me a nasty ping time.
Here is the working config.
On the switch the following config
set system mode router
int vlan 4
ip address 192.168.4.1 /24
int vlan 1
ip address 192.168.2.1 /24
switchport mode trunk
switchport trunk native vlan 4
I think I have a bit similar configuration but unfortunately I didn't figure out yet the appropriate static route I have to add. Please see the graph below where I included all relevant informations regarding the network configuration. Can you please find out the mistake ?
So the objectif is to get internet connection for all hosts beloging to the vlans. Now I have only internet on the server and device that belong to the range 172.16.0.0/24.
I think we are so close to the goal.