[lvs-users] Real server not responding back

Hi, I'm trying to get LVS/IPVS to work for my desired configuration, but facing a weird problem, most likely due to a simple mistake somewhere. For now, I've created one load balancer VM (running Ubuntu 18.04 with LVS director 1.28-3) and one real server VM (running Ubuntu 18.04). Both the VMs a

Re: [lvs-users] Real server not responding back

Thanks for your reply, Per. Wait - you say "hitting the real server, and the real server responding > back to the client IP with a zero length response (ack?)", but > then "but the web server doesn't intercept and respond to the > request" ? > By 'web server' I meant the python web server softwar

Re: [lvs-users] Real server not responding back

Thanks for your reply Andrew. > > It sounds like the server's responses aren't making it through, > meaning that a TCP three-way handshake cannot be completed. > > What is sitting in front of the real server, and *is it stateful*? A > router? A firewall? > > There's no firewall in-front of the re

Re: [lvs-users] Real server not responding back

Thanks Per. I tried rp_filter=2 but it made no difference. Cheers, Nick On Tue, 31 Mar 2020 at 21:12, Per Jessen wrote: > Nick Wilson wrote: > > > rp_filter is disabled (set to zero for all interfaces) on the real > > server. > > On my real servers, rp_filter=2 fo

Re: [lvs-users] Real server not responding back

I can ping the VIP on the real-server. Cheers, Nick On Tue, 31 Mar 2020 at 22:21, Graeme Fowler wrote: > On 31 Mar 2020, at 08:47, Nick Wilson wrote: > > Please chime in if anything else comes to mind. > > A couple of things spring immediately to mind: > > 1. If you setup a

Re: [lvs-users] Real server not responding back

Thanks for explaining it Andrew. My guess is the same -- it's to do with cloud routing/networking, but the cloud hosting company says that their infrastructure and equipment have no restrictions in place, and tunneling should work fine. >> Could you test using a proxy style load balancer? That wa

Re: [lvs-users] Real server not responding back

Hi Julian, >I have an old document for tunnel troubleshooting. I just added > > some configuration examples including recently supported tunnel modes, > HTH: > > > > http://ja.ssi.bg/TUN-HOWTO.txt > > > > At the moment with LVS, VIP on the real-server is no

Re: [lvs-users] Real server not responding back

Thanks for your notes. If you see traffic on tunl0 then the IPIP header is already > removed and you see CIP->VIP TCP packet. Before that, you should see > IPIP DIP->RIP packet on the ens3 (input device). > > My bad, I can see IPIP with a wider tcpdump filter. Flow is like: ens3: DIP -> R