Failing to gain IP address from DHCP after a few days.

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buscseik
Posts: 2
Joined: Fri Apr 06, 2018 11:00 am

Failing to gain IP address from DHCP after a few days.

Post by buscseik » Fri Apr 06, 2018 11:35 am

Hi All,

I have an Softether server set up for simple use of access to my network from anywhere...
My VPN hub is bridge to my local network, and my local DHCP server provide IP for connected clients.

Most of the time it is working without any issue, but sometimes it just stop working. The client still can connect to VPN server, but does not gain IP from DHCP server. To resolve the issue I have to restart completely my server(I am not able to restart the VPN hub only at that stage). This issue occur every few days and make my VPN network very unreliable.

I am not quiet sure which log Should I provide. so I start with this:

Example of log when VPN works fine:

2018-04-06 11:48:26.228 [HUB "VPN"] The connection "CID-2-E4C1A58820" (IP address: 46.7.127.82, Host name: 46.7.127.82, Port number: 2442, Client name: "SoftEther VPN Client", Version: 4.20, Build: 9608) is attempting to connect to the Virtual Hub. The auth type provided is "Password authentication" and the user name is "KriszLaptop".
2018-04-06 11:48:26.228 [HUB "VPN"] Connection "CID-2-E4C1A58820": Successfully authenticated as user "KriszLaptop".
2018-04-06 11:48:26.228 [HUB "VPN"] Connection "CID-2-E4C1A58820": The new session "SID-KRISZLAPTOP-2" has been created. (IP address: 46.7.127.82, Port number: 2442, Physical underlying protocol: "Standard TCP/IP (IPv4)")
2018-04-06 11:48:26.228 [HUB "VPN"] Session "SID-KRISZLAPTOP-2": The parameter has been set. Max number of TCP connections: 2, Use of encryption: Yes, Use of compression: No, Use of Half duplex communication: No, Timeout: 20 seconds.
2018-04-06 11:48:26.238 [HUB "VPN"] Session "SID-KRISZLAPTOP-2": VPN Client details: (Client product name: "SoftEther VPN Client", Client version: 420, Client build number: 9608, Server product name: "SoftEther VPN Server (64 bit)", Server version: 425, Server build number: 9656, Client OS name: "Windows 10", Client OS version: "Build 16299, Multiprocessor Free (16299.rs3_release.170928-1534)", Client product ID: "--", Client host name: "KriszE7440", Client IP address: "192.168.0.17", Client port number: 2442, Server host name: "Kriszvpn2.softether.net", Server IP address: "46.7.19.181", Server port number: 446, Proxy host name: "", Proxy IP address: "0.0.0.0", Proxy port number: 0, Virtual Hub name: "vpn", Client unique ID: "87864C23C480FBBD5872BE7A370AE6EB")
2018-04-06 11:48:26.903 [HUB "VPN"] Session "SID-LOCALBRIDGE-1": The DHCP server of host "DC-53-7C-AE-AA-9F" (192.168.2.1) on this session allocated, for host "SID-KRISZLAPTOP-2" on another session "00-AC-7B-6D-40-BD", the new IP address 192.168.2.171.
2018-04-06 11:48:27.733 On the TCP Listener (Port 443), a Client (IP address 46.7.127.82, Host name "46.7.127.82", Port number 2457) has connected.


Example when VPN fails:

2018-04-06 11:37:13.764 [HUB "VPN"] The connection "CID-19-20FE800A74" (IP address: 46.7.127.82, Host name: 46.7.127.82, Port number: 2297, Client name: "SoftEther VPN Client", Version: 4.20, Build: 9608) is attempting to connect to the Virtual Hub. The auth type provided is "Password authentication" and the user name is "KriszLaptop".
2018-04-06 11:37:13.766 [HUB "VPN"] Connection "CID-19-20FE800A74": Successfully authenticated as user "KriszLaptop".
2018-04-06 11:37:13.766 [HUB "VPN"] Connection "CID-19-20FE800A74": The new session "SID-KRISZLAPTOP-8" has been created. (IP address: 46.7.127.82, Port number: 2297, Physical underlying protocol: "Standard TCP/IP (IPv4)")
2018-04-06 11:37:13.766 [HUB "VPN"] Session "SID-KRISZLAPTOP-8": The parameter has been set. Max number of TCP connections: 2, Use of encryption: Yes, Use of compression: No, Use of Half duplex communication: No, Timeout: 20 seconds.
2018-04-06 11:37:13.774 [HUB "VPN"] Session "SID-KRISZLAPTOP-8": VPN Client details: (Client product name: "SoftEther VPN Client", Client version: 420, Client build number: 9608, Server product name: "SoftEther VPN Server (64 bit)", Server version: 425, Server build number: 9656, Client OS name: "Windows 10", Client OS version: "Build 16299, Multiprocessor Free (16299.rs3_release.170928-1534)", Client product ID: "--", Client host name: "KriszE7440", Client IP address: "192.168.0.17", Client port number: 2297, Server host name: "Kriszvpn2.softether.net", Server IP address: "46.7.19.181", Server port number: 446, Proxy host name: "", Proxy IP address: "0.0.0.0", Proxy port number: 0, Virtual Hub name: "vpn", Client unique ID: "87864C23C480FBBD5872BE7A370AE6EB")
2018-04-06 11:37:15.198 On the TCP Listener (Port 443), a Client (IP address 46.7.127.82, Host name "46.7.127.82", Port number 2300) has connected.


Could anyone help me with this?

Thank you

thisjun
Posts: 2247
Joined: Mon Feb 24, 2014 11:03 am

Re: Failing to gain IP address from DHCP after a few days.

Post by thisjun » Fri Apr 27, 2018 2:42 am

What OS do you use for VPN server?
I think localbridge doesn't work properly.
Please check IP table on SoftEther VPN server when IP assigning fails.
If you can't see hosts on LAN in the IP table, the localbridge fails.

buscseik
Posts: 2
Joined: Fri Apr 06, 2018 11:00 am

Re: Failing to gain IP address from DHCP after a few days.

Post by buscseik » Tue Jun 26, 2018 7:18 am

The client IP does not appear on the server's route table, see output lower



###### IP table on server ##############################################

===========================================================================
Interface List
8...00 ac 66 31 7a 1f ......VPN Client Adapter - VPN
11...40 61 86 00 14 c6 ......NVIDIA nForce Networking Controller
7...00 50 56 c0 00 01 ......VMware Virtual Ethernet Adapter for VMnet1
6...00 50 56 c0 00 08 ......VMware Virtual Ethernet Adapter for VMnet8
1...........................Software Loopback Interface 1
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.2.1 192.168.2.129 25
127.0.0.0 255.0.0.0 On-link 127.0.0.1 331
127.0.0.1 255.255.255.255 On-link 127.0.0.1 331
127.255.255.255 255.255.255.255 On-link 127.0.0.1 331
192.168.2.0 255.255.255.0 On-link 192.168.2.129 281
192.168.2.129 255.255.255.255 On-link 192.168.2.129 281
192.168.2.255 255.255.255.255 On-link 192.168.2.129 281
192.168.49.0 255.255.255.0 On-link 192.168.49.1 291
192.168.49.1 255.255.255.255 On-link 192.168.49.1 291
192.168.49.255 255.255.255.255 On-link 192.168.49.1 291
192.168.121.0 255.255.255.0 On-link 192.168.121.1 291
192.168.121.1 255.255.255.255 On-link 192.168.121.1 291
192.168.121.255 255.255.255.255 On-link 192.168.121.1 291
224.0.0.0 240.0.0.0 On-link 127.0.0.1 331
224.0.0.0 240.0.0.0 On-link 192.168.49.1 291
224.0.0.0 240.0.0.0 On-link 192.168.121.1 291
224.0.0.0 240.0.0.0 On-link 192.168.2.129 281
255.255.255.255 255.255.255.255 On-link 127.0.0.1 331
255.255.255.255 255.255.255.255 On-link 192.168.49.1 291
255.255.255.255 255.255.255.255 On-link 192.168.121.1 291
255.255.255.255 255.255.255.255 On-link 192.168.2.129 281
===========================================================================
Persistent Routes:
None

IPv6 Route Table
===========================================================================
Active Routes:
If Metric Network Destination Gateway
1 331 ::1/128 On-link
7 291 fe80::/64 On-link
6 291 fe80::/64 On-link
11 281 fe80::/64 On-link
6 291 fe80::151:fd9b:1a4f:d511/128
On-link
11 281 fe80::3571:af30:362f:9d32/128
On-link
7 291 fe80::514b:f7da:7319:16cf/128
On-link
1 331 ff00::/8 On-link
7 291 ff00::/8 On-link
6 291 ff00::/8 On-link
11 281 ff00::/8 On-link
===========================================================================
Persistent Routes:
None

###### IP on client###### ##############################################
Unknown adapter VPN - VPN Client:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VPN Client Adapter - VPN
Physical Address. . . . . . . . . : 5E-8D-DB-AE-90-37
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::dcc:627c:6c9d:5e9b%16(Preferred)
Autoconfiguration IPv4 Address. . : 169.254.94.155(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 727616987
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-22-C1-A6-0A-EC-F4-BB-0F-0D-F6
DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
fec0:0:0:ffff::2%1
fec0:0:0:ffff::3%1
NetBIOS over Tcpip. . . . . . . . : Enabled

thisjun
Posts: 2247
Joined: Mon Feb 24, 2014 11:03 am

Re: Failing to gain IP address from DHCP after a few days.

Post by thisjun » Wed Sep 05, 2018 6:21 am

Could you show the IP table of the virtual hub in "Manage Sessions"?

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