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434
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10
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5
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DHCP ISSUE

Networking102
Beginner
Beginner

Hello good day I am trying to configure dhcp with 3 routers I configured the DHCP pool on the main router and established the helpwer addresses on the other two routers but I still am not receiving dhcp on the computers could you please help or explain packet tracer file is below 

1 Accepted Solution

Accepted Solutions

NetworkDave
Participant
Participant

@Networking102,

The HQ Router G0/1 interface (172.30.11.1/24) is connected to PC-Z. The HQ Router DHCP has no Pool set for the 172.30.11.0/24 network.

Both the B1 & B2 Routers have IP-helper-addresses set on their G0/1 interfaces. Remove the IP-helper-addresses from the G0/1 interfaces and configure them on the associated sub-interfaces.

It is important to understand that an IP-helper-address changes the client DHCP broadcast to a unicast message. Therefore the IP-helper-address must be configured on the client-side router interface or the packet will be dropped.

HTH
----------------------------------------------------------------------------------------------------
Remember to mark helpful posts and mark the correct answer as a solution; It helps other users with similar questions.

View solution in original post

5 Replies 5

NetworkDave
Participant
Participant

@Networking102,

The HQ Router G0/1 interface (172.30.11.1/24) is connected to PC-Z. The HQ Router DHCP has no Pool set for the 172.30.11.0/24 network.

Both the B1 & B2 Routers have IP-helper-addresses set on their G0/1 interfaces. Remove the IP-helper-addresses from the G0/1 interfaces and configure them on the associated sub-interfaces.

It is important to understand that an IP-helper-address changes the client DHCP broadcast to a unicast message. Therefore the IP-helper-address must be configured on the client-side router interface or the packet will be dropped.

HTH
----------------------------------------------------------------------------------------------------
Remember to mark helpful posts and mark the correct answer as a solution; It helps other users with similar questions.

Thank you i figured it out before bed last night lol and this was the exact problem I had to put the IP helper address on the sub interfaces and it worked perfectly. Thank you for your solution 

Georg Pauwen
VIP Master VIP Master
VIP Master

Hello,

on a side note, it is also good practice to configure the access ports with 'spanning-tree portfast', in order to have these ports skip the STP listening and learning states, and go into forwarding right away. With DHCP-enabled clients, not having this configured can cause the DHCP requests from the clients to time out.

I had been working on your file, and although @NetworkDave has given you the correct solution, I might as well post it (see attachment).

Thank you for the reply brother and I will take this advice into practice 

dashcam626
Beginner
Beginner

@Networking102 wrote:

Hello good day I am trying to configure dhcp with 3 routers I configured the DHCP pool on the main router and established the helpwer addresses on the other two routers but I still am not receiving dhcp on the computers could you please help or explain packet tracer file is below 


Common DHCP Configuration Problems

Server not giving out addresses. Clients receiving addresses already statically assigned to servers or reserved devices. Clients unable to reach external networks (off subnet) Clients unable to use the Internet with domain names.

Furthermore, do dashcams record audio?

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