topic Re: Configuring DHCP server for a multiple subnet in Operating System - HP-UX

Configuring DHCP server for a multiple subnet

Balaji_3 — Tue, 16 Apr 2002 07:42:23 GMT

Hi All,

One of my colleagues desires a help reg.,Configuaring DHCP Server for Multiple subnets.
So far we implemented DHCP server for Single subnet and its works fine.
Now we need to configure 1 HP9000 Kclass 10.20 as a DHCP server for multiple subnets.
The following are subnet and subnet mask of N/W
specified in Router interface:
Ethernet E0 : 19.195.136.0 255.255.254.0
Ethernet E1 : 19.195.148.0 255.255.254.0
Ethernet E1 : 19.195.152.0 255.255.254.0

DHCP Server is placed in 19.195.136.0 subnetwork.

The requirement is to configure DHCP server in 19.195.136.0 subnet and machine in 19.195.152.0
subnetwork should take 19.195.152.1 to 19.195.152.254 range of ipaddress,machines in 19.195.148.0 subnetwork should take 19.195.148.1 to 19.195.148.254 range of ipaddress,machines in 19.195.136.0 subnetwork should take 19.195.136.1 to 19.195.136.254 range of ipaddress.

First step i created 3 group....and what are the things i have to do in Router..and in Unix server.

Just guide me....

Re: Configuring DHCP server for a multiple subnet

Clemens van Everdingen — Tue, 16 Apr 2002 07:44:37 GMT

Hi,

Solution in thread:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x2fa503bbece8d5118ff40090279cd0f9,00.html

C.

Re: Configuring DHCP server for a multiple subnet

Rainer von Bongartz — Tue, 16 Apr 2002 07:49:26 GMT

Link in above reply might be your solution but keep in mind it is a configuration for 11i and not 10.20.

Regards
Rainer

Re: Configuring DHCP server for a multiple subnet

Steven Gillard_2 — Tue, 16 Apr 2002 07:53:05 GMT

You need to configure your router as a 'DHCP/bootp relay agent', which will also require that you specify the DHCP server's IP address. Refer to your routers documentation on how to do this (if you have a Cisco I can help).

On the server you simply configure separate pool groups for each subnet in /etc/dhcptab as the link in Clemens post shows. The server will use the 'gw' (gateway tag) in dhcptab as the key - the relay agent fills in gateway information on any packet that it relays to the server, and the server will use this information to decide which pool group to use.

Regards,
Steve

Re: Configuring DHCP server for a multiple subnet

U.SivaKumar_2 — Tue, 16 Apr 2002 08:23:21 GMT

hi,
In the server side , better configure DHCP
through SAM.
If your router is a cisco router you can try this ,
#config>interface "dhcp client side ethernet intferce" ( eg. E0 )
on same interface mode give this set of commands.
no ip broadcast address 0.0.0.0
ip broadcast address 255.255.255.255
ip helper-address "your dhcp server's ip"
exit
#config>interface "dhcp server side interface"
(eg . E1 )
no ip broadcast address 0.0.0.0
ip broadcast address 255.255.255.255
exit
#config>ip forward-protocol udp 67
#config>ip forward-protocol udp 68
#config>ip forward-protocol udp 53
#config>exit
#copy run start

regards,
U.SivaKumar

Re: Configuring DHCP server for a multiple subnet

Balaji_3 — Tue, 16 Apr 2002 11:24:10 GMT

As per refernce of follewing forum,
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x2fa503bbece8d5118ff40090279cd0f9,00.html

Mine subnet is 19.195.136.0 and gateway is 19.195.136.1, but the above link i have seen difference i.e.,subnet is 10.134.192.0 but gateway is 10.134.207.253

Its differentiating me,please let me clarify anyof U

Thanks for all ur co-ordination.

Re: Configuring DHCP server for a multiple subnet

Steven Gillard_2 — Tue, 16 Apr 2002 11:33:53 GMT

Thats correct, because the subnet mask in that example is 255.255.240.0. So, 10.134.207.253 is on the same subnet as the address range of 10.134.192.1 -> 10.134.192.254.

Regards,
Steve