Skip to main content

/32 subnets on Ethernet via DHCP





Is it possible to assign to an ethernet host via DHCP a subnet mask of only the host itself, e.g. 192.168.1.123/32? Do common operating systems support this kind of configuration?



I'd like for the hosts to send all of their traffic to the router (and not directly to some other host on the same segment), but still for them to be able to communicate (so no "client isolation"); effectively creating a point-to-point link, but without any client-side configuration.



Update: My intention is to configure a home router running dd-wrt so that all the traffic has to pass through the IP stack on the router, so it can be filtered by some ipfilter rules. I'd hoped for a general solution, some standard way to implement point-to-point Ethernet connections that still can be automatically configured by DHCP for all commons operating systems.




Based on the responses so far, this doesn't seem to be that easy; I'll read some more about VLANs and then reconsider my plans.


Answer



First of all, in order to create point-to-point link, you need at least 4 addresses, so you'll have to use a /30 mask. For example: 192.168.1.0/30




  • Network address: 192.168.1.0/30

  • 1st point address: 192.168.1.1/30

  • 2nd point address: 192.168.1.2/30

  • Broadcast address: 192.168.1.3/30




You'll have to place each host on a different /30 subnet and implement inter-subnet routing on your gateway.



Edit:
You don't write much about your infrastructure or the scalability you want to achieve with this configuration. I suppose your router supports the use of subinterfaces.



Also, no additional client-side configuration will be required if you use a DHCP server in order to distribute the addressing scheme.


Comments

Popular posts from this blog

linux - iDRAC6 Virtual Media native library cannot be loaded

When attempting to mount Virtual Media on a iDRAC6 IP KVM session I get the following error: I'm using Ubuntu 9.04 and: $ javaws -version Java(TM) Web Start 1.6.0_16 $ uname -a Linux aud22419-linux 2.6.28-15-generic #51-Ubuntu SMP Mon Aug 31 13:39:06 UTC 2009 x86_64 GNU/Linux $ firefox -version Mozilla Firefox 3.0.14, Copyright (c) 1998 - 2009 mozilla.org On Windows + IE it (unsurprisingly) works. I've just gotten off the phone with the Dell tech support and I was told it is known to work on Linux + Firefox, albeit Ubuntu is not supported (by Dell, that is). Has anyone out there managed to mount virtual media in the same scenario?

hp proliant - Smart Array P822 with HBA Mode?

We get an HP DL360 G8 with an Smart Array P822 controller. On that controller will come a HP StorageWorks D2700 . Does anybody know, that it is possible to run the Smart Array P822 in HBA mode? I found only information about the P410i, who can run HBA. If this is not supported, what you think about the LSI 9207-8e controller? Will this fit good in that setup? The Hardware we get is used but all original from HP. The StorageWorks has 25 x 900 GB SAS 10K disks. Because the disks are not new I would like to use only 22 for raid6, and the rest for spare (I need to see if the disk count is optimal or not for zfs). It would be nice if I'm not stick to SAS in future. As OS I would like to install debian stretch with zfs 0.71 as file system and software raid. I have see that hp has an page for debian to. I would like to use hba mode because it is recommend, that zfs know at most as possible about the disk, and I'm independent from the raid controller. For us zfs have many benefits,

apache 2.2 - Server Potentially Compromised -- c99madshell

So, low and behold, a legacy site we've been hosting for a client had a version of FCKEditor that allowed someone to upload the dreaded c99madshell exploit onto our web host. I'm not a big security buff -- frankly I'm just a dev currently responsible for S/A duties due to a loss of personnel. Accordingly, I'd love any help you server-faulters could provide in assessing the damage from the exploit. To give you a bit of information: The file was uploaded into a directory within the webroot, "/_img/fck_uploads/File/". The Apache user and group are restricted such that they can't log in and don't have permissions outside of the directory from which we serve sites. All the files had 770 permissions (user rwx, group rwx, other none) -- something I wanted to fix but was told to hold off on as it wasn't "high priority" (hopefully this changes that). So it seems the hackers could've easily executed the script. Now I wasn't able