DHCP server in my LAN not handing out IP to VPN clients

[showstoppre]

Hi

I have a Softether VPN server running on my PC which is connected to my router. VPN hub is bridged to my LAN. So when I connect to my vpn server I expect the router to hand out IP to the client but it doesn't.

I can assign an IP manually that is part of the network and I'm able to ping my router and other devices in LAN. So there is not a problem with bridging.

When I sniffed the Virtual Adapter I noticed that DHCP offers were actually made by the router but they were considered as error.

Any Help would be appreciated

[thisjun]

Could you show captured result?

[cmulk]

Same issue here. I had everything working for a long time with a Linksys home router acting as my DHCP server. Now I have switched to a Belkin AC750 router as my DHCP and softether will no longer accept the address for VPN clients. Similar to the OP, I actually see the proper DHCP requests and reply in tcpdump

root@raspberrypi:/home/cmulk# tcpdump port 67 or port 68
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes

09:24:28.582920 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:c8 (oui Unknown), length 277

09:24:28.584432 IP 192.168.3.1.bootps > 192.168.3.104.bootpc: BOOTP/DHCP, Reply, length 548

09:24:28.841347 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:c9 (oui Unknown), length 283

09:24:28.842659 IP 192.168.3.1.bootps > 192.168.3.106.bootpc: BOOTP/DHCP, Reply, length 548

09:24:28.843998 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:ca (oui Unknown), length 283

09:24:28.845372 IP 192.168.3.1.bootps > 192.168.3.110.bootpc: BOOTP/DHCP, Reply, length 548

09:24:29.102263 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:cb (oui Unknown), length 283

09:24:30.419249 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:cb (oui Unknown), length 283

09:24:30.851723 IP 192.168.3.1.bootps > 192.168.3.113.bootpc: BOOTP/DHCP, Reply, length 548

09:24:30.852735 IP 192.168.3.1.bootps > 192.168.3.113.bootpc: BOOTP/DHCP, Reply, length 548

09:24:30.853428 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:cb
(oui Unknown), length 289
09:24:30.854743 IP 192.168.3.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 548
09:24:32.424341 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:cb (oui Unknown), length 289
09:24:32.425793 IP 192.168.3.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 548
09:24:33.998420 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:cb (oui Unknown), length 289
09:24:33.999854 IP 192.168.3.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 548
09:24:35.571153 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:cb (oui Unknown), length 289
09:24:35.572642 IP 192.168.3.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 548
09:24:35.862424 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ca:d2:4c:db:5c:c8 (oui Unknown), length 269

[thisjun]

Could you show the packet log of SoftEther server and verbose output of the tcpdump?

[cmulk]

Attached the requested logs here. Just seems like the belkin DHCP does something that Softether doesn't like

In the meantime, I've figured out a workaround based on other forum posts by using two virtual hubs - one to bridge to the real network and one to provide DHCP in a specified range (but without NAT). I'll post a write up on that since it has been working well.

Edit:
See workaround here: https://sites.google.com/view/softether-dhcp-bridge
Actually, the idea came from you!: http://www.vpnusers.com/viewtopic.php?f=7&t=5396#p14599