Forum Discussion
VMs on the same VNET can not talk to each other
In that case i suggest you file a ticket so the network can be checked in the back end.
There are couple of things that could be at work here.
When you say 'talk to each other', what do you mean?
You mentioned the VMs have internet connection so i am assuming you are able to access them via RDP. Can you Port Query the RDP port from one VM to another? if so whats the result?
Mean I can not ping between them or can not open TCP connection between them. Yes internet and routing to proper Internet works fine, just communication between them is not. I'm using IP addresses for communication, firewalls on hosts are disabled.
PS C:\Windows\system32> Test-NetConnection 10.0.0.4 -port 3389 WARNING: Ping to 10.0.0.4 failed -- Status: TimedOut WARNING: TCP connect to 10.0.0.4:3389 failed ComputerName : 10.0.0.4 RemoteAddress : 10.0.0.4 RemotePort : 3389 InterfaceAlias : Ethernet 2 SourceAddress : 10.0.1.5 PingSucceeded : False PingReplyDetails (RTT) : 0 ms TcpTestSucceeded : False
The same test running against VM on local subnet works fine as expected
PS C:\Users\cloudadmin> test-netconnection 10.0.1.5 -port 3389 ComputerName : 10.0.1.5 RemoteAddress : 10.0.1.5 RemotePort : 3389 InterfaceAlias : Ethernet 7 SourceAddress : 10.0.1.6 PingSucceeded : True PingReplyDetails (RTT) : 3 ms TcpTestSucceeded : True
OK.
Let do a 'Route Print' and 'ipconfig /all' on 10.0.0.4 to confirm there is no custom route diverting traffic on the OS level.
=========================================================================== Interface List 14...00 0d 3a 02 8d 68 ......Microsoft Hyper-V Network Adapter #2 1...........................Software Loopback Interface 1 15...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2 =========================================================================== IPv4 Route Table =========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 10.0.0.1 10.0.0.4 261 10.0.0.0 255.0.0.0 On-link 10.0.0.4 261 10.0.0.4 255.255.255.255 On-link 10.0.0.4 261 10.255.255.255 255.255.255.255 On-link 10.0.0.4 261 127.0.0.0 255.0.0.0 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 127.0.0.1 306 224.0.0.0 240.0.0.0 On-link 127.0.0.1 306 224.0.0.0 240.0.0.0 On-link 10.0.0.4 261 255.255.255.255 255.255.255.255 On-link 127.0.0.1 306 255.255.255.255 255.255.255.255 On-link 10.0.0.4 261 =========================================================================== Persistent Routes: Network Address Netmask Gateway Address Metric 0.0.0.0 0.0.0.0 10.0.0.1 Default =========================================================================== IPv6 Route Table =========================================================================== Active Routes: If Metric Network Destination Gateway 1 306 ::1/128 On-link 14 261 fe80::/64 On-link 14 261 fe80::8d2a:8b0e:c4ad:807b/128 On-link 1 306 ff00::/8 On-link 14 261 ff00::/8 On-link =========================================================================== Persistent Routes: NoneWindows IP Configuration Host Name . . . . . . . . . . . . : core-dc01 Primary Dns Suffix . . . . . . . : ecomply.local Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : ecomply.local Ethernet adapter Ethernet 2: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft Hyper-V Network Adapter #2 Physical Address. . . . . . . . . : 00-0D-3A-02-8D-68 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::8d2a:8b0e:c4ad:807b%14(Preferred) IPv4 Address. . . . . . . . . . . : 10.0.0.4(Preferred) Subnet Mask . . . . . . . . . . . : 255.0.0.0 Default Gateway . . . . . . . . . : 10.0.0.1 DHCPv6 IAID . . . . . . . . . . . : 335547706 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-21-F4-ED-77-00-15-5D-0A-1D-DE DNS Servers . . . . . . . . . . . : ::1 10.0.0.4 10.0.0.5 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter isatap.{4EA8D25B-523C-4E10-B0A9-3A7FE5508DC1}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes2 things that stands out in OS configuration.
1. The persistent route should be needed
2. Static IP for Azure VM should be setup from the portal and not in the guest OS
Also did the issue start after a change to the environment? (joined domain, etc...)
Since the issue is at the subnet level confirm no subnet NSG or User Define routes on subnet.