How to troubleshoot a routing issue
I am running into a weird problem suddenly. I have Windows 10 on my computer and I have a Hyper-V virtual machine on my computer that runs Windows Server 2019. Inside this, I am hosting a web site. All of the sudden, today, I cannot access my website from my Windows 10 host computer. Externally, it works fine.
My external IP address if 1.2.3.4 (this is fictitious). If I have my girlfriend open Chrome on her computer at home and she puts in https://1.2.3.4, the site comes up just fine. If I go to my Windows 10 host computer and open chrome and put in https://1.2.3.4, it doesn't work. It's like somehow my external address is getting routed differently on my local computer then it is with every other computer.
Is there some way I can diagnose this and maybe refresh my routing tables and/or trace the route to see exactly where my http request is going?
And just to let everyone know, this is a new issue. It worked perfect yesterday.
You are not providing anything to work with so I need to make assumption that
VM and Host are on the same broadcast domain and in the same IP subnet.
- From the host ping IP of the VM
- In the Host, check arp table for VM's MAC
- In the VM, check arp table for host's MAC
- If ARP tables show MACs correctly, L2 works
- If you are missing MACs in ARP you should capture packets to see which operating system has issue with ARP
- you may want to allow ICMP in both OSs just to make sure the pings will work as well, so you can confirm L3
- if L3 is working, then move layer up and see if the connection between two OSes is being established with
netstat -on - if the connection is OK, then you need to look what is happening in the web server... (this point can grow too wide without knowing details of your server)