topic Re: how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX? in ICX Switches

how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX?

Jeronimo — Thu, 30 May 2024 06:50:52 GMT

Hi Friends.

It assume it configured multiple subnet on a interfce ve 100 and needs dhcp relay at the int ve 100.

Ex. int ve 100, ip add 1.1.1.1/24, ip add 2.2.2.2/24 ip add 3.3.3.3/24

As a rsult of my test, relay agent ip(GIADDRESS) in dhcp packet is 1.1.1.1, the lowest IP address.

At cisco, it has primary ip, his ip address is relay agent ip(GIADDRESS).

But ruckus icx has no primary ip address.

How do I specify 2.2.2.2 or 3.3.3.3 as relay agent ip(GIADDRESS)?

Or not?

Regards.

Re: how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX?

Chandini — Fri, 31 May 2024 17:53:52 GMT

Hi Jeronimi

Thank you for reaching us

Based on the requirement mentioned could you please let me know if you are assigning multiple IP with different subnet to same vlan and then looking for setting DHCP helper address to accordingly assign IP to the end device ?

I would suggest creating vlan and assigning a separate IP address to that vlan instead of clubbing and supernetting all together.

Below is the link that will help you configure IP helper-address

https://docs.commscope.com/bundle/fastiron-09010-dhcpguide/page/GUID-643304A1-0198-432A-A36B-524D141D94DD.html

Please feel free to post if any concerns.

Thanks

Re: how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX?

Jeronimo — Mon, 03 Jun 2024 00:42:09 GMT

Hi Chandini.

Thanks for reply.

Ok, I also knew how to set ip help-address and supernetting.

However, some customers want to set up several different IP subnets on one interface.

In this case, if Cisco sets ip add 1.1.1.1/24, ip add 2.2.2.2/24 secondary 3.3.3.3/24 secondary, the relay IP address (giaddress) in the dhcp-request packet is sent to 1.1.1.1 because the primary IP address is specified as 1.1.1.1.

However, since the secondary IP cannot be specified in Ruckus ICX, the relay IP (giaddress) is sent to the lowest IP address on a interface.

For example, if it is set as 3.3.3.3/24 1.1.1.1/24 5.5.5.5/24, "1.1.1.1" is the relay IP (giaddress).

This will not give the customer the desired result.

If it were Cisco, the above case could be set to 3.3.3.3/24, 1.1.1.1/24 sec, 5.5.5.5/24 sec, and the relay ip address would be 3.3.3.3.

Do you understand this situation?

I want to know if there is a way to make 3.3.3.3/24 a relay ip address in the above example in ICX.

Regards.

Re: how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX?

Chandini — Mon, 03 Jun 2024 17:21:43 GMT

Hi Jeromico

Ack and Thanks for reaching us

Is 3.3.3.3 your DHCP server IP address ? If not what is the IP address of the DHCP server ?

Thanks

Re: how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX?

Jeronimo — Tue, 04 Jun 2024 00:00:06 GMT

Hi Chandini.

I assumed a topology like below.

On above, ICX send dhcp paket with lower ip address as relay agent ip.

Do you understand it?

Regards.

Re: how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX?

Chandini — Tue, 04 Jun 2024 17:12:12 GMT

Hi Jeromico

Ack and Thanks for sharing the details. Let me check about this and revert back to you.

Thanks

Re: how to specify a subnet of multiple subnet on same int ve to relay dhcp packet at ICX?

jim_laus — Thu, 05 Dec 2024 22:56:41 GMT

Did you ever find a solution to this? I am looking for info on this but for a slightly different scenario.

I have to change the ip scheme I use on my vlans. I would like to run dual subnets (Old subnet and new subnet) on the current vlan while I switch everything over, eventually removing the old subnet. I would like to control which subnet will be relayed for DHCP request during this process.

Thanks