networking – netplan configuration not applying ethernet LAN

After a power cycle, I’m unable to see my ethernet interfaces in ifconfig with the following netplan configuration. ethMine shows up in ip link show, but is not upped.

$ cat /etc/netplan/01-netcfg.yaml 
# See also: https://netplan.io/reference
network:
  version: 2
  renderer: networkd
  ethernets:
    ethMine:
      addresses:
        - 192.168.1.67/25
  vlans:
    ethA.200:
      id: 200
      link: ethA
      addresses: ("192.168.1.167/26")
  wifis:
    abcd:
      dhcp4: yes
      dhcp6: no
      addresses: (10.10.10.15/24) 
      gateway4: 10.10.10.1
      nameservers:
        addresses: (8.8.8.8, 8.8.4.4)
      access-points:
        "myssid":
          password: "mypasswd"
  • On Ubuntu desktop.
  • There are no other netplan configs.
  • /etc/network/interfaces is commented out
  • Only after a sudo netplan apply does the interface come up.
$ dmesg | grep ethMine
(    2.881002) r8169 0000:26:00.1 ethMine: renamed from enp38s0f1

after sudo netplan apply:

$ dmesg | grep ethMine
(    2.881002) r8169 0000:26:00.1 ethMine: renamed from enp38s0f1
(  359.512589) r8169 0000:26:00.1 ethMine: Link is Down
(  362.332948) r8169 0000:26:00.1 ethMine: Link is Up - 1Gbps/Full - flow control off
(  362.332977) IPv6: ADDRCONF(NETDEV_CHANGE): ethMine: link becomes ready

Can I force my netplan apply to run later in case there is a race?

ESXi network behavior host losing connection to LAN

I have an esxi host with 2 virtual machine, if i switch on both VMs my host loses connectivity to the LAN but sill pinglable from the VMs. If i switch off one of the VMs, my Host is pingable from LAN and the VM that is still on.

networking – Error connecting Windows 10 PCs to a MAC on a LAN

The Setup:

1x Mac Mini (MM), running OS X El Capitan Version 10.11.6(not Mac server)

5x Windows 10 (W10) PCs

1x LAN wifi

1x LAN ethernet

The Challenge:

Connect all 5 PCs to the MM over the wired LAN or Wifi and map folders on the MM as additional Drives (Eg, P, Q, R etc) on the W10 PCs, as so as to share files stored on the MM. BTW: The MM is not used as a workstation, more as a “server” or pseudo-server.

The Method:

From the PCs Command prompt on the W10 PCs run “net use T: “1nn.nnn.1.14ffffff” /persistent:yes. (real values hidden for security)

The Initial Outcome:

2 of the 5 PCs connected and drive letters assigned – no problems,

3 of the PCs could not connect, error message 71, “No more connections can be made to this remote computer at this time because there are already as many connections as the computer can accept.”

Attempted Solution:

On the W10 PCs; increased the number of currentlogons in the registry from 10 to 100, but this made no difference. I think i should be doing something like this on the MM…

Second Outcome:

No effect.

Question:

How do I increase the number of (network?) connections that the MM can accept? I believe this would solve the issue, but if I’m barking up the wrong tree, I would gladly be pointed to another one.

Thanks in Advance
Dave

networking – Using 2nd router as extension of my main router, LAN works but WLAN doesn’t and after “x” time it just refuses to work at all

I recently followed a guide how to use an old router to extend my network at home. Everything was smooth, made sure the range I have set the DHCP Server won’t conflict with anything (Main Router, from my ISP.) I’ve used 192.168.1.30 – 192.168.1.254.

Moving on to the old router. I’ve disabled it’s DHCP so it wouldn’t conflict with the server, set the old router’s IP Address as 192.168.1.15. I’ve setup the wireless options as well, made sure it has a different SSID, even changed the channel selection so it wouldn’t collide with anything. The LAN interface works, at the moment I’m connected to it as I’m typing this question. The only problem I’ve had is whenever an I try to connect to it wirelessly via an Android or iPhone it has limited connectivity. I am connected to the network, but I do not have an internet, the LAN ports work however. The 2nd/old router acts like a switch it seems. Any advice how to set this up properly?

networking – LAN connection problem

I am running into an issue that my campus LAN connection is not getting connected.I am using Ubuntu 20.04.It was fine 2 days ago but now it shows authentication problem even though i enter correct credential.The LAN connection requires no CA certificate.I just need to enter my credentials.Even after entering correct credentials,it again prompts me for entering password without showing whether password was correct or not.As of password,i am pretty much sure that it is correct.

To diagnose issue, I ran the following command in terminal

nmtui-connect

it then showed me the available wifi and ethernet connection.But when i tried connecting to ethernet,it says

Could not activate connection:
Connection ‘Profile 1’ is not
available on device enp2s0
because device has no carrier

enter image description here

here Profile 1 is the name for ethernet connection i am using.How can i solve this problem ?Thanks

network – Does a LAN to LAN with different subnet configuration is secure?

I plan to implement the following network configuration :

Internet ((cable A))

Router A
(192.168.0.x)((WAN:cable A)(LAN1:cable B)(LAN2:)(LAN3:)(LAN4:))

Router B
(192.168.1.x)((WAN:)(LAN1:cable B)(LAN2:)(LAN3:)(LAN4:))

The first LAN port of router A is connected into the first LAN port of router B, but both routers are in a different subnet.

Usually, when I setup two routers together, I do a double NAT configuraton (LAN to WAN) or a LAN to LAN in the same subnet.

I know the following facts:
In a double NAT configuration such as this one,

Internet ((cable A))

Router A
(192.168.0.x)((WAN:cable A)(LAN1:cable B)(LAN2:)(LAN3:)(LAN4:))

Router B
(192.168.1.x)((WAN:cable B)(LAN1:)(LAN2:)(LAN3:)(LAN4:))

Hosts from router B can communicate with hosts from router A.
Hosts from router A can’t communicate with hosts from router B.

In a LAN to LAN in the same subnet configuration, any hosts can communicate to any. It’s the same subnet.


In the network configuration I plan to implement, LAN to LAN but in a different subnet, I noticed that hosts from both network can’t be reached. Is this a secure way to isolate networks, at least better than double NAT ?

The connected router B gets an IP address in the router A subnet (192.168.0.x).

Also, I did not have to define any static routes to get internet access, I have difficulties to understand how this is possible since router A gateway does not ping.

networking – Assign LAN IP to Ethernet device on RPi

I’m trying to use a Raspberry Pi as an wifi-to-ethernet extender. I’ve followed this guide to get to where I am now, which looks like the following, where --- is Wi-Fi and === is Ethernet:

(Router, 192.168.0.1) --- (Laptop, 192.168.0.26)
    |
    + --- (Raspberry Pi, 192.168.0.10, 192.168.4.1) === (3D Printer, 192.168.4.2)

From my laptop, I am able to connect to the Pi at 192.168.0.10 (e.g. for ssh) just fine. Also, from the Pi, I can visit “192.168.4.2” and see the 3D Printer’s web page.

What I would like to do is visit “192.168.4.2” on my laptop and see the 3D Printer’s page. How can I do this? Is it a router setting I have to apply or something on my laptop, or both?

For reference, here is the Pi’s /etc/dnsmasq.conf:

interface=eth0
dhcp-range=192.168.4.2,192.168.4.250,255.255.255.0,12h

/etc/rc.local:

#!/bin/sh -e
_IP=$(hostname -I) || true
if ( "$_IP" ); then
  printf "My IP address is %sn" "$_IP"
fi

iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE

exit 0

Output of ip a on RPi:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether b8:27:eb:c6:b2:ef brd ff:ff:ff:ff:ff:ff
    inet 192.168.4.1/24 brd 192.168.4.255 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::bfc8:4ac7:f06f:20ce/64 scope link
       valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether b8:27:eb:93:e7:ba brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.10/24 brd 192.168.0.255 scope global dynamic noprefixroute wlan0
       valid_lft 86172sec preferred_lft 75372sec
    inet6 2601:154:c202:7570::2/128 scope global dynamic noprefixroute
       valid_lft 294221sec preferred_lft 294221sec
    inet6 2601:154:c202:7570:b50b:1c11:45c:f51f/64 scope global dynamic mngtmpaddr noprefixroute
       valid_lft 294447sec preferred_lft 294447sec
    inet6 fe80::f9bd:f939:b142:b8fb/64 scope link
       valid_lft forever preferred_lft forever

And output of ip a on laptop:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: wlp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 9c:b6:d0:e3:d7:e1 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.26/24 brd 192.168.0.255 scope global dynamic noprefixroute wlp2s0
       valid_lft 83501sec preferred_lft 83501sec
    inet6 2601:154:c202:7570::1/128 scope global dynamic noprefixroute
       valid_lft 291539sec preferred_lft 291539sec
    inet6 2601:154:c202:7570:d4c9:339a:8311:c494/64 scope global dynamic noprefixroute
       valid_lft 294446sec preferred_lft 294446sec
    inet6 fe80::e2bd:4076:6b15:6f47/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

router – Devices on LAN unable to connect with each other

I am using a Medialink Router, and access to the internet is working perfectly. For some reason, none of the devices on the LAN are unable to connect with each other (I have tried ping, ssh, and VNC). I contacted Medialink, who are saying that they will send me a new unit. What could the issue be?

ubuntu – TCP handshake failed after forward LAN connection through VPN

We have some secured web services(including websites) that are only accessible when connected to a VPN provided by the service owner. Since the VPN account is only allowed to be connected by one user at a time, we planned to configure one of our machines in our LAN to be the gateway to handle the traffic towards the secured service.

  1. The VPN is connected via OpenConnect client on a machine running Ubuntu 18.04 bionic.

    It was verified proper route was added automatically after VPN is connected and we can get ping responses from the secured server address, we can also curl the content of the secured website.

  2. The interface of VPN is tun0, the interface of LAN is eth0

    We run the following command to enable LAN forward:

    sysctl net.ipv4.ip_forward

    iptables -A INPUT -i tun0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT

    iptables -A FORWARD -i eth0 -o tun0 -j ACCEPT

    iptables -A FORWARD -i tun0 -o eth0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT

    iptables -t nat -I POSTROUTING -o tun0 -d <secured_host> -j MASQUERADE

  3. We then added a static route to our router to set the next-hop of traffic to the secured service to be the machine running the VPN.

  4. When testing from other machines in the LAN, we can now get ping response from the secured server, but we cannot open the website in a browser. If we tried to curl from the secured server, we got:

    curl: (35) schannel: failed to receive handshake, SSL/TLS connection failed(curl from windows CMD)

  5. Checking tcpdump on the machine running VPN shows:
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
04:14:51.058123 IP <LAN_machine>.53902 > <secured_host>.https: Flags (SEW), seq 2060814575, win 64240, options (mss 1418,nop,wscale 8,nop,nop,sackOK), length 0
04:14:51.073952 IP <secured_host>.https > <LAN_machine>.53902: Flags (S.), seq 1469838894, ack 2060814576, win 4254, options (mss 1460,sackOK,eol), length 0
04:14:51.074936 IP <LAN_machine>.53902 > <secured_host>.https: Flags (.), ack 1, win 64240, length 0
04:14:51.077473 IP <LAN_machine>.53902 > <secured_host>.https: Flags (P.), seq 1:190, ack 1, win 64240, length 189
04:14:51.106822 IP <secured_host>.https > <LAN_machine>.53902: Flags (.), ack 190, win 4443, length 0
04:15:01.106027 IP <secured_host>.https > <LAN_machine>.53902: Flags (R.), seq 4255, ack 190, win 0, length 0
04:15:01.107200 IP <LAN_machine>.53902 > <secured_host>.https: Flags (.), ack 1, win 64240, length 0
04:15:01.122306 IP <secured_host>.https > <LAN_machine>.53902: Flags (R.), seq 1, ack 190, win 0, length 0

What else should I do to make things work? Many thanks in advance.

debian – Unable to connect to website on internal server within LAN

Complete noob with things like this so bare with me; all help is greatly appreciated.

I have a server at home that I intend on hosting multiple websites i’ll call website 1 & website 2.

Operating System: Debian 10
Webserver: Apache2
SSL Certs: Certbot
Website CMS: WordPress

So everything was working fine, I created all of the port forwarding rules in my router, virtual servers in Apache2 running fine, and both sites were accessible both internally and externally.

I needed something to manage mail for website 2, being a newbie I used my old method of using Microsoft 365. It has proven itself well for website 1’s needs.
I followed all of the instructions through the wizard, changed the nameservers to Microsoft’s four ns*.bdm.microsoftonline.com on my original domain provider and all seemed okay.

Yesterday when I tried to access website 2 to work on it, I get a “Server not found” error in FireFox. I turned wifi off on my mobile and it worked straight away, a friend elsewhere verified it worked on their computer at their house.
Website 1 however still works both internally and externally however it only works if prefixed with “www.” if I try without it does not resolve.

I have tried to log in using the local ip address which automatically turns into the domain for website 2; same when using the server’s hostname.


My Hosts file looks like this:

127.0.0.1 localhost website1.co.uk website2.co.uk

127.0.1.1 central


If anyone could help, I would be eternally greatful 😀

Thank you,
Joey.