Tailscale doesn't reconnect after WAN failover on upstream router - vpn

QUESTION:
Is there a way to trigger Tailscale to restart in a scenario like the following so that packets again flow to a remote Tailscale subnet over a backup ISP connection?
Scenario: Tailscale does not reconnect after my upstream router fails over to its backup ISP connection.
Prior to failover, local client machines can ping public IP addresses -- 8.8.8.8 for example -- as well as private IP addresses on the other side of a Tailscale subnet router -- 10.0.0.2 for example.
After failover, local clients regain public Internet access, but the private network on the other side of the Tailscale subnet router remains unreachable. The remote Tailscale subnet never becomes reachable again, even after waiting over 15 minutes.
The upstream router fails back after plugging the local WAN1 ethernet cable back in. Clients can still access the public Internet and can again reach the remote Tailscale subnet.
Test configuration:
Tailscale is running on a local Linux machine with IP forwarding enabled.
IP address is 192.168.0.2.
Default route is via 192.168.0.1.
Tailscale flags:
--advertise-routes=192.168.0.0/24
--snat-subnet-routes=false
--accept-routes
Local upstream router has two WAN ports configured for failover only.
WAN1 connects to a cable modem in bridge mode.
WAN2 connects to an LTE router in bridge mode.
LAN IP address is 192.168.0.1.
Static route to 10.0.0.0/8 via 192.168.0.2.
Tailscale is running on a remote EC2 instance in an AWS VPC with IP forwarding enabled.
IP address is 10.0.0.2.
Default route is via 10.0.0.1.
Tailscale flags:
--advertise-routes=10.0.0.0/8
--snat-subnet-routes=false
--accept-routes

tailscaled generally reacts to linkchange events, like links going up or down, and figures out which interface has the default route. If both interfaces remain up and both interfaces have a default route, it may not know which one to use.

Related

Set up a Direct Network between Host and Guest VMWare

I have a Soft PLC running inside a VMWare environment (Guest - Windows 8).
I want to connect to it from the Host (Windows 10) using the internal connections without having to set up a physical network switch.
My understanding of the documentation states that this should be achieved by Host only networking
https://docs.vmware.com/en/VMware-Workstation-Player-for-Windows/15.0/com.vmware.player.win.using.doc/GUID-93BDF7F1-D2E4-42CE-80EA-4E305337D2FC.html
And I've my PC Set up as:
The Network card in the Guest is set up as 192.168.0.244
On the Host, the network VMNet1 (Should be the DHCP Server) is Dynamic (DHCP) and resolved to 192.168.67.1 and VMNet8 (Should be the connection to the Guest) is also DHCP and has resolved to 192.169.73.1
All subnet masks are at 255.255.255.0 (DHCP defined?)
Even if I assign VMNet8 or VMNet1 to physical IP at 192.169.0.1 or 192.169.0.244 or 192.169.0.1 or even 192.168.0.12, I cannot ping the network card inside the host.
Am I missing something here with my setup? What am i doing wrong or has anyone got a step by step process for setting up a direct network connection between the Guest and host for testing communications without an external switch?
(I've disabled teh network connections between each setting change)
Found the issue.
The VM should have been set to NAT
The Network address of the adapter Inside the Guest set to the IP address I'm looking for
On my Host - VMNet 1 left alone as this is the DHCP Server
And set the VMNet 8 (Bridged connection between Guest and Host) to an IP address within a range of the subnet
And after disabling and re-enabling the connections, I can ping the PLC (192.168.0.1) running in simulation on the Guest from outside in the Host.
(Allows me to test node-red on the host connecting via OPC to PLCSim Advanced running on the Guest).

Accessing connected devices to a local network wirelessly

Hello Everyone!
I want to know that is there any way to access a photocopier machine which is connected to a computer through Ethernet wire and that computer is connected to my WiFi network?
P.S: What if I don't know the IP assigned to that Photocopier machine?
If the wireless network is part of the wired network you should have any problem reaching the photocopier.
If you don't know the IP address, you can reach it by host name if the DHCP and DNS are working properly. If you are on an Active Directory infrastructure and DHCP and DNS are integrated it should be transparent.
If you are on your home with a "home" router they usually do the hostname to IP resolve (DNS).
You can nslookup hostname in your machine to see if your dns is resolving the ip address. you can also ping hostname or ping ip address to test that you can reach the desired host. Some hosts block ping (ICMP) requests, please note that ping is ping does not respond is not a definitive solution.
Please note that in your home router you should use your router or default gateway to be the DNS also, and then add the google public DNS or your ISP.
Also when connecting the access point to an existing network you may have 2 DHCP servers providing IP addresses to hosts, you should disable DHCP on the Access Point and connect the AP to the network using the switch port and not the WAN port (the WAN port will try to do NAT and assign a different set of IP addresses).

The VM can ping the host machine, but can not ping other public IP

I in a remote Server (I call it host machine) setup the OpenStack Ocata.
And in the OpenStack Ocata I created a VM, the VM use the Security Group (named allow ping & ssh), which is created by myself:
Now, I can use my Mac ping the VM. but can not ssh connect to the VM.
And in the VM(it's IP is 192.168.1.4 and floating IP is 103.35.202.3), I can ping 192.168.1.1 and 103.35.202.1(the host machine's public IP), but can not ping google.com or other public IP.
Why in my Mac I can ping the VM but can not ssh to it?
Why in the VM I can ping the host machine, but can not ping other public IP?
where is the issue?
Currently the only Egress traffic allowed out is for ICMP. Egress is missing for TCP/UDP. Add in Egress rules for both UDP (should help resolve the DNS issue) and TCP (should resolve the SSH issue.)
After adding in the Egress rules for TCP - test ssh again.
After adding in the Egress rules for UDP - test DNS resolution, if you are still running into issues then you may want to verify the DNS servers used when configuring the network.

Server or router assigns ip address

Im new to networking,If I have a window server and in that server I have a normal soho router, will that server assign the ip address to each device? or will that router do it. What I've learned is that the server is suppose to be the DHCP but sometimes if you plug a router directly in the server it kicks the server off and the router starts to assign the ip address. If that is so, how would you fix that?
Most routers will take on the role of a DHCP Server out-of-the-box. That is, they will distribute ip addresses to whatever DHCP Client requests an address.
By default, a Windows server will not have set up a fully configured DHCP Server.
By default a Windows machine (either client or server) and most other networked devices will have set their network interface to be a DHCP Client.
Therefore, by simply plugging in your Windows server to one of your router's LAN ports will make the router set the Windows server's network interface to the next available ip address using DHCP.
If you were to connect more devices to the router's LAN ports it will still be the router that assigns those extra devices an ip address.
Ideally you want only one DHCP server in your network.
Also, if you want your Windows server to always have the same ip address you can do two things:
Log in to the router and set a fixed ip address for your Windows server network card's unique MAC address.
Modify the router's DHCP range (e.g. from .10 to .200) so it leaves some addresses free (e.g. .1 to .9 and from .201 to .254). Then set your Windows server network card's fixed IPV4 address to a fixed address (e.g. .210). You may also need to set a DNS server then.
This is only briefly skimming the subject of IPV4 networks, DHCP and friends so when you have some time try to read the wikipedia pages for them.
http://en.wikipedia.org/wiki/IPv4
http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
Server assigns your public IP address, in fact it assigns your router a public IP address.
While the router assigns each device connected a local IP address.
With respect to your router, the IP address server assigns it is its IPv4 address and the addresses router assigns to its clients are IPv6 address.
When you browse the internet through your router, the router reads your requests and responds according to that IPv6 address and when the router requests something to the server, server sees it as its IPv4 address. :)

Connect to a server on a private network

I am learning how to create an ubuntu server to use to host a database and run a script as a thread to do some things for my graduation project...
I installed ubuntu server with lamp environment and managed to connect it to an ethernet local network that connects to the internet .. my design looks like this
except the router is also connected to a dsl modem and to the internet...
I can easily connect to the server from the local network but how can I connect to it from outside this private network ?
I know the router public ip address and the server private ip address
You need port forwarding. mean, in your router settings you define that incoming requests to specific port/protocol will redirects to specific ip (of the ubuntu).
See https://en.wikipedia.org/wiki/Port_forwarding
You will need to set up port forwarding on the router such that the router's external port 80 is forwarded to the server's private port 80.
What router is it? Its guide should detail how to set up port forwarding

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