VLAN Client not getting ip from DHCP Server

[Energy]

This should be so simple but it seems that it isnt that simpel at all.

 

My test eqiupment.

SMC Switch SMC TigerStack II 10/100/1000 SMC8926EM/SMC8950EM

DHCP Server 2008 (IP - 172.10.5.50/24 - GW 172.10.5.1)

 

Running Running log (See attachment for full LOG)

VLAN database

VLAN 1 name DefaultVlan media ethernet state active

VLAN 2005 name VLAN2005 media ethernet state active

VLAN 2050 name VLAN2050 media ethernet state active

interface VLAN 2005

IP address 172.10.5.1 255.255.255.0

!

interface VLAN 2050

IP address 172.10.50.1 255.255.255.0

IP DHCP relay server 172.10.5.50

interface ethernet 1/1

switchport allowed vlan add 2005,2050 untagged

switchport native vlan 2050

interface ethernet 1/24

switchport allowed vlan add 2005,2050 untagged

switchport native vlan 2005

 

My Client is in port 1 and DHCP Server is in port 24

 

I can ping DHCP Server if i set the client ip to (also the dhcp server can pint client)

IP - 172.10.50.100/24

GW - 172.10.50.1

 

Funny fact is also that the DHCP Server actualy thinks it give out and lease to the client???

But it never recieves it?

 

I think my problem is something with the switch routing but i dont know?

SMC LOG.txt

Edited November 28, 2014 by Energy

[Energy]

Anyone??

[Davit2005]

Has the DHCP server had it's Default Gateway set to the ip address of Switch of its vLANs.

 

I've seen issues with that in a lab at home.

 

I.E if the server is on vlan 1, the vlan 1 ip address on the switch I think need be set as default gateway of the server.

[Energy]

well the DHCP server is on VLAN2005 and its gateway is the switch VLAN ip address.

 

So isnt the issue :-\

[DMcCoy]

You don't have routing enabled. The manual says this is "ip routing" which I don't see in the config.

[Energy]

Well that doesnt make much sence... Because i can ping from one vlan to another?

 

And the web interface even say its enabled?

[SHimmer45]

for each of the vlans i had setup on a 3com switch the default gateway for each vlan was set to the switches IP (no the vlans IP) with routing enabled and DHCP helper on and pointing to the DHCP server

[Energy]

Im not sure i understand you correct. But the switch ip is the VLAN switch ip adresse? So its kinda the same.

[SHimmer45]

i mean the IP your are connecting to manage the switch as a whole, which by default isnt part of any vlan.

[Energy]

When you setup a VLAN and give it a IP adresse it become the Gateway to the switch and you can manage it this way. if i just give it ip adresse it will just be on vlan1 as defualt and you can manage it from there 2. But this make no sence at all. Because if i set this to be my gateway i will never reach anything at all.

[localzuk]

For VLANs and inter-VLAN routing to work correctly, it should be set up so that a client on a VLAN uses the routing device (in this case your switch) as its default gateway. Each VLAN has its own IP address, and this should be used to differentiate each VLAN (so, a client on vlan 1 would have the IP address of vlan 1 on the routing device as its gateway, a client on vlan 2 would have the IP address of vlan 2 as its gateway and so on).

 

The routing device should have IP routing enabled, and should have a "default route" enabled, to handle any traffic that wouldn't be routed between the VLANs (eg. out to the internet).

 

On my HP switch, I have to define the DHCP address helper on each VLAN individually, it isn't a single setting for the entire switch - according to the manual for your switch, this is the case for it also. So, you need to add "IP DHCP relay server 172.10.5.50" to every VLAN you want to be able to get a DHCP address from.

 

Also, as you're using different VLANs, you have to define a matching DHCP scope in your DHCP server. So, if you expect a client on VLAN 1 to get an address, your DHCP server requires a scope which matches "172.10.5.1" to be able to hand an address out.

[SHimmer45]

 

The routing device should have IP routing enabled, and should have a "default route" enabled, to handle any traffic that wouldn't be routed between the VLANs (eg. out to the internet).

 

On my HP switch, I have to define the DHCP address helper on each VLAN individually, it isn't a single setting for the entire switch - according to the manual for your switch, this is the case for it also. So, you need to add "IP DHCP relay server 172.10.5.50" to every VLAN you want to be able to get a DHCP address from.

 

this is what i was very badly trying to get at

[Energy]

For VLANs and inter-VLAN routing to work correctly, it should be set up so that a client on a VLAN uses the routing device (in this case your switch) as its default gateway. Each VLAN has its own IP address, and this should be used to differentiate each VLAN (so, a client on vlan 1 would have the IP address of vlan 1 on the routing device as its gateway, a client on vlan 2 would have the IP address of vlan 2 as its gateway and so on).

 

The routing device should have IP routing enabled, and should have a "default route" enabled, to handle any traffic that wouldn't be routed between the VLANs (eg. out to the internet).

 

On my HP switch, I have to define the DHCP address helper on each VLAN individually, it isn't a single setting for the entire switch - according to the manual for your switch, this is the case for it also. So, you need to add "IP DHCP relay server 172.10.5.50" to every VLAN you want to be able to get a DHCP address from.

 

Also, as you're using different VLANs, you have to define a matching DHCP scope in your DHCP server. So, if you expect a client on VLAN 1 to get an address, your DHCP server requires a scope which matches "172.10.5.1" to be able to hand an address out.

 

That is exactly what i have done?

 

First of all i dont have any gateway yet so no defualt gateway because of that.

 

I have a Scope on my DHCP server that is 172.10.50.x/24

My client is on the 2050 vlan where the ip helper is set on the switch. Ofcourse i can't give my client a gateway..

[localzuk]

Hmm... So, your DHCP server has the gateway set to 172.10.5.1?

[teejay]

I'd also be checking you haven't got any firewalls in the way blocking UDP 67 or UDP 68.

[Energy]

Hmm... So, your DHCP server has the gateway set to 172.10.5.1?

 

 

Yes it is.

[Energy]

I'd also be checking you haven't got any firewalls in the way blocking UDP 67 or UDP 68.

 

I have no firewall enabled on the system for same reason.

 

--------------------------------------------------------------------------------------

 

I did find something odd, i tried to add a new Scope to the DHCP Server.

And know its trying to give the IP adresse from that scope to the client, but still client doesnt recieve it.

 

But it seems to be related to that vlan is not tagged correctly then? It should be givin a IP from VLAN 2050 instead.

[localzuk]

That is odd. Your config does appear to show that VLAN 2050 should be "untagged" on port 24, where your DHCP server is plugged in - and that is right. Your client is on port 1 and untagged for VLAN 2005, which is also correct. So, I'm at a bit of a loss!

[Energy]

If i do this it my client is actually getting and ip adresse.

 

interface ethernet 1/1

switchport allowed vlan add 2050 untagged

switchport native vlan 2050

interface ethernet 1/24

switchport allowed vlan add 2005 untagged

switchport native vlan 2005'

 

But then my next problem is that i actually want my client to access the VLAN2005 but if i add it again

 

switchport allowed vlan add 2005,2050 untagged

switchport native vlan 2050

interface ethernet 1/24

switchport allowed vlan add 2005,2050 untagged

switchport native vlan 2005

 

they client doesnt recieve and ip???

[localzuk]

The manual for this switch isn't particularly clear. With the changed config (ie, the first of the 2 blocks you just posted), is the client able to ping the dhcp server after getting its IP?

 

The reason I ask is, I don't think the "switchport allowed vlan" command does what you think it does. By default, it appears that all inter-vlan traffic is allowed on that switch (same with the HP switch I've got here). I'm pretty sure you'd only add multiple VLAN ID's if you're adding a trunk with "tagged" rather than "untagged" frame types, or if you're using GVRP to determine which VLAN is assigned to what.

[Energy]

I enabled GVRP and also on the ports. Also added those untagged VLANS and now everything works. The Client gets the right IP from DHCP VLAN2050 and can also ping the DHCP Server.

 

Thanks for the help.

Edited December 3, 2014 by Energy