I have an ISP box connected to a Netgear WiFi router.
Internet <-->[WAN] ISP box [LAN]<-->[WAN] Netgear router [LAN]<-------> Win7 laptop 192.168.0.x/24 192.168.1.x/24
I successfully configured both to enable IPv6 connectivity to Internet (with IPv6 next-hops configured in ISP box towards the WiFi router, whatever). Very happy, but I probably screwed a few IPv4 things in network layers of my Windows 7 laptop. I suspect that they are corelated, but I cannot find the spot :-(
First, laptop connected via WiFi, Internet is accessible via IPv4 (192.168.1.x/24) and IPv6. I discovered that although I can connect to a distant private network via VPN (Forticlient, user/password accepted and connection established), no traffic is received; any ping -4 to the remote computers/routers fail:
C:\Windows\system32>ping 192.168.10.70 Pinging 192.168.10.70 with 32 bytes of data: Request timed out. Request timed out. Reply from 192.168.0.254: Destination host unreachable. Request timed out. Ping statistics for 192.168.10.70: Packets: Sent = 4, Received = 1, Lost = 3 (75% loss),
Notice that 192.168.0.254 is my ISP box (gateway for WiFi router), there is no such IP on remote network (VPN), where these packets are expected to go!
C:\Windows\system32>ipconfig Windows IP Configuration Ethernet adapter Local Area Connection 9: Connection-specific DNS Suffix . : Link-local IPv6 Address . . . . . : fe80::b8a8:bf09:275c:682c%31 IPv4 Address. . . . . . . . . . . : 192.168.250.17 Subnet Mask . . . . . . . . . . . : 255.255.255.255 Default Gateway . . . . . . . . . : [...] Wireless LAN adapter Wireless Network Connection: Connection-specific DNS Suffix . : lan IPv6 Address. . . . . . . . . . . : 2a01:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx IPv6 Address. . . . . . . . . . . : 2a01:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx IPv6 Address. . . . . . . . . . . : fd69:cdc6:cb9d::a6b IPv6 Address. . . . . . . . . . . : fd69:cdc6:cb9d:0:bcac:ce5b:6ae4:4caf Temporary IPv6 Address. . . . . . : 2a01:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx Temporary IPv6 Address. . . . . . : fd69:cdc6:cb9d:0:7d0a:715c:58db:8656 Link-local IPv6 Address . . . . . : fe80::bcac:ce5b:6ae4:4caf%12 IPv4 Address. . . . . . . . . . . : 192.168.1.239 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : fe80::xxxx:xxff:fexx:xxxx%12 192.168.1.1
The routing table seems normal:
C:\Windows\system32>route print -4 =========================================================================== Interface List 31...00 09 0f aa 00 01 ......Fortinet SSL VPN Virtual Ethernet Adapter 30...00 09 0f fe 00 01 ......Fortinet virtual adapter 24...xx xx xx xx xx xx ......Intel(R) Ethernet Connection I218-LM #3 16...xx xx xx xx xx xx ......Microsoft Virtual WiFi Miniport Adapter #2 14...xx xx xx xx xx xx ......Bluetooth Device (Personal Area Network) 12...xx xx xx xx xx xx ......Intel(R) Dual Band Wireless-AC 7260 1...........................Software Loopback Interface 1 =========================================================================== IPv4 Route Table =========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.239 10 << Default route 127.0.0.0 255.0.0.0 On-link 127.0.0.1 306 127.0.0.1 255.255.255.255 On-link 127.0.0.1 306 127.255.255.255 255.255.255.255 On-link 127.0.0.1 306 a.b.c.d 255.255.255.255 192.168.1.1 192.168.1.239 10 << VPN server @ a.b.c.d 192.168.1.0 255.255.255.0 On-link 192.168.1.239 266 192.168.1.1 255.255.255.255 On-link 192.168.1.239 10 << WiFi router 192.168.1.239 255.255.255.255 On-link 192.168.1.239 266 << WiFi address 192.168.1.255 255.255.255.255 On-link 192.168.1.239 266 192.168.10.0 255.255.255.0 192.168.250.18 192.168.250.17 1 << Remote net 192.168.14.0 255.255.255.0 192.168.250.18 192.168.250.17 1 << Remote net 192.168.250.17 255.255.255.255 On-link 192.168.250.17 257 << VPN connection 184.108.40.206 240.0.0.0 On-link 127.0.0.1 306 220.127.116.11 240.0.0.0 On-link 192.168.1.239 266 18.104.22.168 240.0.0.0 On-link 192.168.250.17 257 255.255.255.255 255.255.255.255 On-link 127.0.0.1 306 255.255.255.255 255.255.255.255 On-link 192.168.1.239 266 255.255.255.255 255.255.255.255 On-link 192.168.250.17 257 =========================================================================== Persistent Routes: None
I then noticed that when I disable the laptop WiFi and connect an Ethernet cable between the laptop and the LAN switch of either the router or the ISP box, the laptop fails at getting an IPv4 address (stays on APIPA 169.254.x.x).
According to Wireshark, it seems to send a DHCP request repeatedly but no answer is received. Traffic from other devices of the LAN is well seen on Wireshark trace.
I tried ipconfig /release then /renew with no more success. May it be necessary to use more intrusive methods to reset IPv4 stack to a cleaner state?
Comparison with another laptop
I tried all those tests on another Win7 laptop: it encountered no such issues at all.
- VPN connection is OK, ping 192.168.10.70 is successful.
- The routing table is similar (with some different IP addresses, as expected).
- Wired connection obtains an IP address with no delay.
All of that is strongly supposing that the issue is really located on the first laptop (and not router stuff). But now I need your help to investigate further...