Re: Shared DHCP pool for multiple VLAN interfaces
Simon <[email protected]>
| Newsgroups | gmane.network.dhcp.isc.dhcp-client |
|---|---|
| Message-ID | <764B18CB-4002-4B38-A511-790394B11223__11357.8011443437$1637859898$gmane$org@thehobsons.co.uk> |
Fabian Druschke <[email protected]> wrote: > Now i'm facing an issue which doesn't seem to be that simple. > > In my network topology i got a bunch of different VLANs, VLAN 405-480, and VLAN 700-750. > > The DHCP server should serve leases to requests, coming from these interfaces. But they should share a single DHCP range only, 10.20.0.0/16. > > Is it possible to accomplish this goal, serving DHCP leases on all these VLAN subinterfaces, and serving DHCP leases for this single subnet? The short answer is “it depends” ! The fuller answer is probably not very short at all. The first thing you need to clarify is the network topology - just saying “I have VLANS” is no more informative than “I have a number of LANS”. Specifically, how are they connected, how is the addressing done, and most importantly how do you differentiate traffic and route it to the correct VLAN ? I ask the latter as your question makes it sound like you have a number of separate networks (VLANs), all sharing the same IP subnet (10.20.0.0/16). That’s a tricky one to pull off reliably. I can see a situation where (e.g.) a host with address 10.20.10.20/16 in VLAN 405 talks via a router at 10.20.0.1/16 to communicate with another host at 10.20.10.21/16 which also talks via a router at 10.20.0.1/16. As general IPv4 addressing goes, that just isn’t going to work - principally because IPv4 doesn’t have the concept of on-link and off-link prefixes like IPv6 does, and hence the two devices would not know they needed to go via the router to talk to each other. Unless the router does a lot of proxy-ARP which itself could be interesting with that size of network. So more information needed before anyone can usefully answer your query. Simon _______________________________________________ ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. dhcp-users mailing list [email protected] https://lists.isc.org/mailman/listinfo/dhcp-users