Switching

Hi Guys,

 

Recently i was installing Juniper EX2200 with DHCP relay enable.

The DHCP server is using Microsoft server 2003 that act as AD and DNS server

 

in my configuration I have two vlans,

interfaces {
vlan {
        unit 100 {
            family inet {
                address 192.168.100.1/24;
            }
        }

        unit 110 {
            family inet {
                address 192.168.110.1/24;
            }
        }
    }
}

forwarding-options {
    helpers {
        bootp {
            server 192.168.100.252;
            interface {
                vlan.110;
            }
        }
    }
}

vlans {
    server {
        vlan-id 100;
        interface {
            ge-0/0/0.0;
   }
   l3-interface vlan.100;
}

    user {
         vlan-id 110;
         interface {
           ge-0/0/16.0;
    }
    l3-interface vlan.110;
    }
}

 

 

This is the result when troubleshooting

juniper@EX> show helper statistics
bootps:
Received packets: 554
Forwarded packets: 554
Dropped packets: 0
Due to no interface in fud database: 0
Due to no matching routing instance: 0
Due to an error during packet read: 0
Due to an error during packet send: 0
Due to invalid server address: 0
Due to no valid local address: 0
Due to no route to server/client: 0

 

Is this show that Juniper EX2200 has been forwarding packet to the DHCP server (192.168.100.252)?

DHCP server IP: 192.168.100.252/24 while the user network: 192.168.110.0/24

However the user is still failed to get IP from the DHCP server.

How do i configured the DHCP server (Microsoft server 2003) to distribute different IP pools to different vlan?

Sorry if this is a repost.

 

Thanks for any replies

 

This the the main checklist for all items that need to be configured in Server 2003 for DHCP.  Make sure all of the required items were performed on the server.

 

http://technet.microsoft.com/en-us/library/cc759445%28WS.10%29.aspx

 

In your case some possible reasons.

 

Is the DHCP server authorized in AD after installation?

 

Are the server level options correct? Do not include any variable that needs to change for the individual pools at the server level.  Make sure default gateway is handled by the pool.

 

Are the multiple pools created for the subnets of DHCP requests being relayed?  In Server 2003 you don't assign pools to vlans but the matching to pools is done based on a match between pool address scope and the subnet of the request origin in the DHCP relay.

Thanks spluuka for your quick reply. its really helpful.

 

From Juniper is it configured correctly?

forwarding-options {
    helpers {
        bootp {
            server 192.168.100.252;
            interface {
                vlan.110;
            }
        }
    }
}

Do i need to add

 

set forwarding-options helpers bootp source-address-giaddr

or

set forwarding-options helpers bootp relay agent-option

??

 

Can we monitor DHCP request from DHCP server?

For the Juniper side, if your vlan is setup with the ip address range you want to match the DHCP server you should be fine with that configuration.  KB11020 notes all the vlan settings needed.  You will need the source address if this is not a layer 3 vlan to pass an address for the server.

http://kb.juniper.net/InfoCenter/index?page=content&id=KB11020

For MS Server 2003

Enable DHCP logging

http://technet.microsoft.com/en-us/library/cc780941%28WS.10%29.aspx

The logs are in the windows\system\logs folder

The codes are listed here

http://technet.microsoft.com/en-us/library/cc776384%28WS.10%29.aspx

Thanks Spluuka. the problem is from MS server 2008, it wont reply DHCP request from another subnet except his own network.

Appreciate ur reply.

Do you have another scope configured for that subnet?

In this configuration there is only one scope for one subnet.

this problem is solved. there is an issue from the MS 2008. While testing using MS2003 it works perfectly.

 

 

Anyway Thanks

christiannh,

 

Did you find out what was the problem with ms 2008? We are having some problems with ms 2008 vs 2003 as well. Why does 2008 not work?