double tag dhcp ip allocation

  • 10 February 2016
  • 6 replies

we have summit x460-24t extreme networks switch . I want to trunk port to send and receive double tagged ports and allocate IP addresses via DHCP .
example : -say outer vlan (service vlan) is x and inner vlan (customer vlan) is y . Then it should allocate IP address from a particular pool .
Currently we have following setting for single tagged vlan which works well .

create vlan "vlan400"
configure vlan vlan400 tag 400
configure vlan vlan400 ipaddress
enable ipforwarding vlan vlan400
configure vlan vlan400 dhcp-address-range -
configure vlan vlan400 dhcp-options default-gateway
configure vlan vlan400 dhcp-options dns-server
enable dhcp ports 21-24 vlan vlan400

Thanks .

6 replies

Userlevel 6
Hi Sumeet,

I believe you are looking to provide IP-address to hosts which are present in the Customer VLAN.... where this customer VLAN is not present in the X460-24t and the switch only provides VMAN services... please correct me if my understanding is wrong on the same.

Hi Sumeet,

Please follow the link.

Manas Ranjan
sorry for my late reply .
to (Mohandoss, Karthik, Employee)
my system is connected to trunk port of switch .
I want that trunk port to accept double tagged packets and allocate ip addresses (from a pre-defined pool)) to macid requesting via dhcp .
For now , I can choose vlan (outer and inner ) which are not present on switch , so no conflict .
But , single tagged vlan's are already configured and running on other ports . I hope it won't be an issue.
i read the link you gave .

I have a few questions
(1)enable jumbo frame has to be done for all ports or only those involved in double tag vlan ?
(2) 'enable dot1p examination inner-tag port 24 ' does this allocate ip based on inner tag at port 24 ?
Userlevel 6

The inner tag would not be looked by the switch rather it would only look at the outer tag and if that VLAN is present in the switch and is configured to provide DHCP IP then it would.

Been a long time , sorry .
to Mohandoss, Karthik,
here is what I did
* X460-24t.4 # enable jumbo-frame ports all* X460-24t.5 # create vman vman1
* X460-24t.6 # configure vman vman1 tag 3050
* X460-24t.7 # configure vlan vman1 ipaddress
* X460-24t.7 #configure vman vman1 add ports 21-24 tagged
Then I gave IP to my device which sends packet with outer (service) vlan 3050 and iner (customer) vlan 1004 and ether type 0x8100. Note that vlan 1004 is not defined on extreme switch .
I tried to ping . did not happen.
When I try
enable dot1p examination inner-tags ports 21
I get
error:port 21 has dot1p examination enabled . disable dot1p examination and re-issue this command.
Also , note that single tag vlans in range 100 to 900 are already configured and running on ports 21-24 . Is that a problem ?
Does the dot1p examination command tell switch to ignore inner vlan for double tagged packets ?