topic Re: DHCP server icx 7750 in ICX Switches

DHCP server icx 7750

flemming_hansen — Sat, 20 Oct 2018 17:36:29 GMT

After upgrading icx 7750 from 08.0.40 to 08.0.80 My multiple DHCP servers is malfunctioning.

A PC can get a lease, but a iPhone or IP phone cannot get a lease.

What can be wrong?

Re: DHCP server icx 7750

hashim_bharooc1 — Sat, 20 Oct 2018 19:12:22 GMT

Hi Fleming,

So PC ONLY works and sounds like you have dedicated DHCP Dedicated servers?
Is that assumption is correct?

The more details the better for me to understand the issue.

If you compare the old configs from 8040 are they the same as new 8080 configs?

Re: DHCP server icx 7750

jardel_almeida1 — Sun, 21 Oct 2018 10:39:58 GMT

Hi,

What does not work?
Do devices not get IP? Run a wireshark to identify what is impacting the problem, or see the VLWN / WLAN / ICX settings.
Share your configuration here to verify.

Re: DHCP server icx 7750

martin_martin — Sun, 21 Oct 2018 17:39:50 GMT

I presume the PC is directly connected and the iphone via an access point.
Is the accesspoint working ? can you access it via the controller?

regards
Martin

Re: DHCP server icx 7750

flemming_hansen — Mon, 22 Oct 2018 00:13:46 GMT

Hi Thanks for your reply.

The iPhones are connected via WiFi, and the IP phones are hardwired. They will not optain an IP address. PC's get an IP address, via WiFi and hardwired.
I got a guest network on another VLAN, which has a DHCP server on a Palo Alto firewall, and the iPhone can get an IP from there.

I will find the configs.

regards
Flemming

Re: DHCP server icx 7750

electa_smith — Mon, 22 Oct 2018 05:09:00 GMT

I don't know how

Re: DHCP server icx 7750

electa_smith — Mon, 22 Oct 2018 05:10:13 GMT

After factory reset I can't sign in even with super and sp-admin

Re: DHCP server icx 7750

netwizz — Mon, 22 Oct 2018 11:56:47 GMT

Are they within a different VLAN?

If yes, did you not save before the reload and perhaps loose some configuration settings such as the ip helper addresses?

Re: DHCP server icx 7750

jijo_panangat — Sun, 11 Nov 2018 06:54:22 GMT

You may run a wire shark on the server/client and check if the iPhone gets an dhcp-offer from server, At least we will know in which phase it is failing in the DORA process.

Please open a tac case as this requires a troubleshooting session to isolate the problem.

Re: DHCP server icx 7750

PC_JP — Thu, 09 Jan 2025 04:11:20 GMT

I too faced the same issue today in version 08.0.95...
I created a dhcp pool in ICX7750 and then it is reached to WLC
from the Ruckus AP, the pc can get the dhcp ip address whereas the mobile phone donot receive the ip address or gets connects. both are in the same SSID.
Where as when i used the tplink router and enabled dhcp on it and when i passed it wlc both gets connected i dont know why? Anyone found the solution?

Re: DHCP server icx 7750

BenBeck — Thu, 09 Jan 2025 15:08:45 GMT

Can you pcap and check the DORA (Discover, offer, request, ack) process? Please try 8095q and if you see unexpected behavior, feel free to open a support case.

Re: DHCP server icx 7750

PC_JP — Wed, 15 Jan 2025 00:29:11 GMT

SW version is 08.0.95pT203

I have created 2 VLANS. For example vlan 100 and vlan 101
For vlan 100 I have used the dhcp pool created on ICX7750 and For Vlan 101 I used the TP-link router to provide DHCP. Both PC+ Mobile working fine with VLAN101 in SSID101 but VLAN 100 has SSID 100 in AP on which only PC get connects.

On checking via Wireshark:

--On Laptop (Wi-Fi)
--Receives DHCP Pool Address
DHCP Request:
*Option:(50) Requested IP address (192.168.92.4)
DHCP ACK:
*Option:(54) DHCP Server Identifier(192.168.92.1)

--On Mobile (Same Wi-Fi)
--Do not lease IP address, no Request and ACK, Only Discover is seen in Wireshark
*Option:(53) DHCP Message Type (Discover)
DHCP: Discover (1)
*Option:(61) Client Identifier
Client Mac Address:<------>
*OPtion:(12) Hostname
Hostname: <Redmi-12-5G>
*option:(55) Parameter Request list
Length:12
Parameter Request List Item: (1) Subnet mask
Parameter Request List Item: (3) Router
Parameter Request List Item: (6) Domain name Server
Parameter Request List Item: (15) Domain name
Parameter Request List Item: (26) Interface MTU
Parameter Request List Item: (28) Broadcast Address
Parameter Request List Item: (51) IP Address lease time
Parameter Request List Item: (58) Renewal time value
Parameter Request List Item: (43) vendor-specific Information
Parameter Request List Item:(114) DHCP Captive-Portal
Parameter Request List Item: (108) IPv6-Only Preferred

switch configuration:
ip dhcp-server pool vlan100
excluded-address 192.168.92.1
!
excluded-address 192.168.92.100 192.168.92.254
lease 1 0 0
network 192.168.92.0 255.255.255.0
option 3 ip 192.168.92.1
deploy
ip helper-use-responder-ip

interface ve 100
vrf forwarding abc
ip address 192.168.92.1 255.255.255.0
ip helper-address 1 192.168.92.1

also globally i have enabled
ip dhcp-server enable
ip dhcp-server relay-agent-echo enable

Re: DHCP server icx 7750

PC_JP — Wed, 15 Jan 2025 00:29:33 GMT

SW version is 08.0.95pT203

On checking via Wireshark:

--On Laptop (Wi-Fi)
--Receives DHCP Pool Address
DHCP Request:
*Option:(50) Requested IP address (192.168.92.4)
DHCP ACK:
*Option:(54) DHCP Server Identifier(192.168.92.1)

interface ve 100
vrf forwarding abc
ip address 192.168.92.1 255.255.255.0
ip helper-address 1 192.168.92.1

also globally i have enabled
ip dhcp-server enable
ip dhcp-server relay-agent-echo enable

Re: DHCP server icx 7750

PC_JP — Tue, 14 Jan 2025 23:54:13 GMT

@Benbeck

Please check it.