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DHCP messages

DHCP messages

Created: Oct 23, 2020 23:34:52Latest reply: Oct 27, 2020 23:04:13 692 9 2 0 0
  Rewarded HiCoins： 1 (problem resolved)
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Hi guys,


How are DHCP messages (Discover, Offer, Request, ACK/NAK) sent by Huawei devices and why? (Example: Unicast, Broadcast, Multicast, Anycast)


DHCP

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Zebra
Created Oct 24, 2020 07:43:10

Hope this help

DHCP

Des


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(1) (0)
chenhui
Admin Created Oct 24, 2020 01:58:12

Hi, 

For Huawei devices, the Discovery and Request are sent in multicast, Offer and ACK are sent in unicast.
When the DHCP client request a IP address from the DHCP server, it doesn't hold an IP and doesn't recognize the DHCP server IP address, so it send the packets with the multicast. For the DHCP server, it will send back the Offer and ACK packets to the IP which assigns to the client.

You can refer the packets capturing result below:

DHCP


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Herediano
Herediano Created Oct 24, 2020 16:44:12 (0) (0)
Hi @chenhui

Can you confirm if Discover and Request are Broadcast or multicast? I believe they are broadcast for the reasons described by @Zebra below.  
Herediano
Herediano Reply Herediano  Created Oct 24, 2020 16:45:22 (0) (0)
Also the packet capture shows 255.255.255.255 so I guess those two are Broadcast.  
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2#
DDSN
DDSN Admin Created Oct 24, 2020 01:18:21

Hi Herediano,
Please wait patiently. Our engineers are looking for answers to your questions.
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(1) (0)
3#
chenhui
chenhui Admin Created Oct 24, 2020 01:58:12

Hi, 

For Huawei devices, the Discovery and Request are sent in multicast, Offer and ACK are sent in unicast.
When the DHCP client request a IP address from the DHCP server, it doesn't hold an IP and doesn't recognize the DHCP server IP address, so it send the packets with the multicast. For the DHCP server, it will send back the Offer and ACK packets to the IP which assigns to the client.

You can refer the packets capturing result below:

DHCP


View more
  • x
  • convention：

Herediano
Herediano Created Oct 24, 2020 16:44:12 (0) (0)
Hi @chenhui

Can you confirm if Discover and Request are Broadcast or multicast? I believe they are broadcast for the reasons described by @Zebra below.  
Herediano
Herediano Reply Herediano  Created Oct 24, 2020 16:45:22 (0) (0)
Also the packet capture shows 255.255.255.255 so I guess those two are Broadcast.  
(2) (0)
4#
Zebra
Zebra Created Oct 24, 2020 07:43:10

Hope this help

DHCP

Des


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  • x
  • convention：
(1) (0)
5#
Herediano
Herediano Created Oct 24, 2020 16:45:56

Thank you @Zebra, pretty clear info.
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Zebra
Zebra Created Oct 25, 2020 06:20:47 (0) (0)
it's good to hear that.  
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6#
anyeEE
anyeEE Created Oct 24, 2020 18:27:52

Nice job, thank you!
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7#
paoladr
paoladr Created Oct 27, 2020 23:04:13

Great job!
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