[ian5142]

Hello All,
I am trying to set up a DD-WRT PC (x86_64 build, most recent version), paid version. It is running on an AMD Phenom(tm) II X4 840T Processor with 16GB of RAM and an SSD. 2 PCI-E Ethernet cards are installed as well. 1 is four-port, 1 is one-port.

I need to subnet the network so that there is a DHCP Lease Pool of about 10,000 or so. 1,000 addresses might work with a really low lease time of 1 hour or something.

Attached a screenshot of the current DHCP settings that I have tried. I can't put a number larger than 254 in the maximum IP address block.

[kernel-panic69]

The lowest you can go is /22 because the max is 999 and you won't get all available addresses.

https://svn.dd-wrt.com/browser/opt/etc/config/base.nvramconfig#L63

[lexridge]

You may be able to set up 10 or more bridges on different IPs and assign a dhcp server for each one. You will probably also want to enable the recently added ARPd service.

[lexridge]

I just did some quick testing. I set up one additional bridge br1 and assigned the IP of 10.0.0.1/17. I then created a new dhcp server for br1 with a start IP of 2 and a max of 10000. Note, I did this on a router, not a x86 PC, but should work the same regardless.

I assigned wlan0.1 to br1 to test by connecting via my phone. I got an IP of 10.0.35.70 so it appears to be working. Also, the 254 limit doesn't seem to exist on additionally created dhcp servers under the Networking tab, as it does on the Basic Setup tab.

So it looks like you will only need to create one bridge and one new dhcp server attached to it to make this work.

EDIT: Also tested on a spare lan port on my pc and got an IP of 10.0.22.140/17. I simply assigned lan3 on the router to br1 to test this.

[egc]

You are talking about an installation with 10000 concurrent users and want to put them in one broadcast domain?

You must be joking.

I suggest you hire professional help and use professional equipment for that kind of installations

[lexridge]

[ian5142]

OK, progress.
I was able to do what Lexridge suggested about creating br1, the Ethernet ports are then unbridged from the main bridge (br0) and assigning a bunch of my Ethernet ports to it, br1. Then creating a second DHCP server for br1. The problem is, I tested the setup with 2 different computers.

br0 - IP 192.168.128.1 / 17, DHCP range start IP: 192.168.250.1 - 192.168.250.254
br1 - IP 192.168.128.1 / 17, DHCP range start IP: 192.168.129.2 - 192.168.130 ++, I didn't calculate it exactly but 4000 addresses total. To make it easier to tell, I also changed the lease time on br1 to 120 minutes.

The weird part is both computers get an IP address, but one is from the DHCP pool for br0 and the other from br1. They are both plugged into ports that should be getting IPs from br1.

Also, small GUI issue, can't see the Root MAC in br1, it is a � symbol or some other character, changes when the page reloads.

I can provide screenshots if required.

[DWCruiser]

Without fully understanding the issues involved, my first reaction to the stated overlapping networks in br0 and br1 would be a network design vulnerable to complications and confusions down the track.

While in theory a network of /17 would give you some 32,768 usable IP addresses, practical limitations RAMs and CPU power on a consumer-grade router, may result in its developers placing restrictions on the router's OS. Unbeknown to users.

It's simply a case of 'Horses for Courses'.

I note you are configuring it on a PC hardware platform, it runs on DDWRT. No necessarily designed for industrial usage. I may be wrong here.

As egc suggested, you may need professional help for scoping cover.

[kernel-panic69]

Using the same subnet for both br0 and br1 is going to cause problems.

[lexridge]

[Alozaros]

once you make it with the DHCP, than you have to fiddle with

Administration > Maximum Connections on my Dynalink are 24576 by default...but if you ve
30k addresses you may need to make it up high ---max is 1048576

same goes for DNSmasq if you use it..you'd need to increase
Maximum Concurrent Requests -- default is 150 but, you may need way more than that...i had a case where i needed to up the number to 350, i think with DNSmasq max is 500..and this is very busy network....with 30k clients..not very sure if DNSmasq can handle such a network...

I guess with decent CPU and lots of ram and good WAN pipe(SFP) you can handle the enterprise network....but, im curious for how long ... and what will be the overall performance...

[ian5142]

Yes, you were correct. My issue was that br0 and br1 were overlapping. I changed the subnet to /20. Then made br0 vastly different from br1.

Now both PCs get IPs from br1's DHCP pool, like they are supposed to.