DHCP multiple interfaces

Posted on 2003-02-23
Medium Priority
Last Modified: 2013-12-27
I'm having trouble setting up DHCP on multiple interfaces.

I have had DHCP on my primary external interface for almost a year and decided to add an extra leg to my network. I configured the second interface, brought it up and set up DHCP the same as for my primary but it doesn't recieve an address.

If anyone has any suggestions I would be grateful.

Question by:calic0
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Expert Comment

ID: 8013051
I really need some more info regarding the current setup, but I will go ahead and outline the process...

1)  First identify that you want dhcp on the second interface by "touch dhcp.hmeX" where the "X" is the suffix to whatever your interface name is (ie. hme, qfe, eri, etc...)

2)  Second create "/etc/hostname.hmeX" and make sure that the file is empty.

3)  Make sure that your "/etc/inet/hosts" file only has a line in it defining the localhost loopback "  localhost".

4)  Make sure the file "/etc/defaultrouter" is empty.

5)  Make sure the file "/etc/resolv.conf" is empty.

6)  Edit "/etc/nsswitch.conf" and add the entry for "DNS" to the line for hosts.  This will read:  hosts: files dns

7)  Reboot and enjoy

*If it doesn't come up at this point I would try and ping the server to make sure that you can access it in order to receive a dhcp addresss.


Author Comment

ID: 8014614
Actually I have no problem with setting up DHCP in general. I have had DHCP running on my primary interface for ages. My problem exists in the second interface. It just won't retrieve an IP even after all values in all needed files have been filled.

In general I assume that there shouldn't be any problems with a second interface recieving a DHCP address?

Accepted Solution

dmaloy1 earned 300 total points
ID: 8016059
I agree it shouldn't be a problem, but I have not tried it myself.

One thing you may try is to bring down the original interface and then see if you can get an address on the second one by starting S34dhcp.

Lastly, I would make sure that you have your route tables setup properly to ensure that you can even reach the server.
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Expert Comment

ID: 8019034
Hello friend,

I would suggest looking into this post:

I was having similar problems with DHCP and I think it might be related to my MAC address. I'll let you know if anything comes of my situation. Good luck.


Expert Comment

ID: 8164790
i think you did not plumb your interface..

type this

# ifconfig hmeX plumb

after that you need to run :

# ifconfig hmeX ip.add.re.ss broadcast + up

please replace hmeX with your interface..

and be sure that you have an entry with your hostname.hmeX
and hosts file.

Expert Comment

ID: 8164809
oops..a litle mistake..if you want to get an ip address from dhcp server..

the command should be

# ifconfig hmeX auto-dhcp

LVL 18

Expert Comment

ID: 10425922
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