Multicast support

[astronomy]

@robinsmidsrod
Thank you for your prompt response, it's got me thinking at least in the right direction... I am going to reply here but I feel that I've torn this thread off topic a little, Im still working to rethink my multicast setup. I'm not having much luck. For now I'm sticking with sanboot from http since it is working (so long as I don't boot more than 20 machines at once...) I've created a small test network consisting of my laptop, the server, and one gigabit unmanaged switch inbetween. I then run apachebench to attempt to find weaknesses. ab -kc 100 -t 30 http://192.168.10.1/ibmcd.iso seems to be working, though the first few times I ran it, nothing seemed to happen on the server but now the server shows sending ~23.5MiB/s (then down to 0 and back up each second, though I don't really understand that...) just as it does at work with the full network connected and 20 machines booting. I know if I go for more than 20 machines at once my server output drops to 1MiB/s or lower (just like with the tftp)... I also noticed on my last batch of 100 (the size of the network was reduced from 120 for unrelated reasons) that 3 machines in particular would cause server output to drop below 100KiB/s. I got around this by disconnecting those machines until the others were finished downloading the image (the second the problem machine is disconnected all others immediately go back to the expected speed).

I'm going to take your suggestion and setup AoE and vblade, though I'm not sure how I can test that from home for 100 concurrent connections. I've been researching how to identify bottlenecks in my network but I'm coming up pretty short. I'm simply connecting 7 Cisco 2950's (24port 10/100 managed switches) to one central unmanaged gigabit switch, the server is connected to the central switch. For the cisco switches I load factory defaults, disable STP on vlan1 then enable portfast on all ports. There is nothing else present in the network, and no bridging/forwarding from the server. It's only job is this.

I also notice that if I use WoL to boot them all simultaneously I get a lot of issues with the initial undionly.kpxe download... which still suggests to me that my network is having trouble with all that traffic. A lot of the machines time out on the initial DHCP as well. In addition, if it's a CMOS setting utility that's being run I also load up an undi for dos driver and a packet driver then use wget to let the server know it completed... this can fail as well if too many machines are going at once (for my last batch, all 100 failed to get an address in dos when booted one at a time each 3 seconds). I definitely feel like I'm doing something wrong with my network, should 100 simultaneous dhcp requests be a problem? I would appreciate any point in pretty much any direction. Also, thank you for your ipxe menu example you prepared for the world! It helped me quite a bit when converting my dynamic pxelinux menu to work with ipxe's menu system (which rocks!).

Edit: I just realized my cable connecting my server to the gigabit switch wasn't allowing gigabit!!! swapped that out and obviously i'm getting 10x the speed out of the server now. I have a feeling I'm too novice at networking yet to handle such a project efficiently but hopefully I'll slowly get there. I'm going to rerun a couple wires at work and make sure i'm getting gigabit to the server. What an obvious oversight. This certainly doesn't explain my congestion issues (draggin the whole network down to sub KiB/s ranges, then when that connection gets terminated the rest jump back up to the expected speeds)