NETWORK PRESENCE ABOUT SERVICES PRODUCTS TRAINING CONTACT US SEARCH SUPPORT
 


Search
display results
words begin  exact words  any words part 

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [FW1] DHCP tbru FW1



If there is a router out on that subnet then you can use a helper. The Cisco
way is to enter interface config mode for that interface and enter :- ip
helper-address x.x.x.x (ip of dhcp server) This will turn the broadcast into
a unicast and send it to server (rules permitting). It will then allow the
dhcp server to return the address and all is lovely. The other option is
configure a nt box as a 'DHCP Relay Agent' and it can forward requests to
your DHCP server. These devices will both insure that an IP from the
approriate scope will be returned.

Hope that helps

Russell Goodwin

-----Original Message-----
From: James Edwards [mailto:[email protected]]
Sent: 24 October 2000 13:39
To: '[email protected]'; [email protected]
Subject: RE: [FW1] DHCP tbru FW1



I'm sure someone who knows more about this stuff will disagree with me or
have found some cool way to do this but we tried to do that very thing and
were completely unsuccessful.  

The problem is not the DHCP server but rather the original device (call it
A) and the nature of DHCP itself.  When a device that uses DHCP boots up, it
does not have an IP address and if it is told to use DHCP, it then
broadcasts a DHCP request out on the network.  A DHCP server listening on
that network then picks it an IP address out of its tables and sends it
back.  The only information contained in the original packets from A that
allows the DHCP server to answer it is the MAC address of the original
device.  The MAC address portion of the packet is changed everytime it
traverses a device like a router or switch or firewall so the DHCP packet
loses it originator as soon as it moves off the local network.

Save yourself a lot of trouble and make a little NT box that does nothing
but DHCP for that network.  We worked on it for weeks and never got it to
happen.

Once again, someone out there probably has a cool way to do this but it is
just simpler to put it on the same network.

Hope this helps

Jim Edwards

-----Original Message-----
From: [email protected] [mailto:[email protected]]
Sent: Monday, October 23, 2000 4:54 PM
To: [email protected]
Subject: [FW1] DHCP tbru FW1



Just curious, 

has anyone used a product sold via UUNET called IPLINK and passed
DHCP requests "thru" a FW1 to an internal DHCP server?

I need to be able to pass DHCP requests from a leg on the firewall to my
internal DHCP server and have it allocate addresses from the proper scope.
Any problems to watch out for? I haven't really done anything with
BROADCASTS,
although I noticed the network object has a checkbox to allow them.

Otherwise I might just have the router manage a pool instead.



============================================================================
====
     To unsubscribe from this mailing list, please see the instructions at
               http://www.checkpoint.com/services/mailing.html
============================================================================
====


============================================================================
====
     To unsubscribe from this mailing list, please see the instructions at
               http://www.checkpoint.com/services/mailing.html
============================================================================
====


================================================================================
     To unsubscribe from this mailing list, please see the instructions at
               http://www.checkpoint.com/services/mailing.html
================================================================================



 
----------------------------------

ABOUT SERVICES PRODUCTS TRAINING CONTACT US SEARCH SUPPORT SITE MAP LEGAL
   All contents © 2004 Network Presence, LLC. All rights reserved.