35
votes
Accepted
My global IP address is 192.168.1.xxx?
I am using Ubuntu and found out that my global IP address is…
It's not global. Do not pay much attention to scope global; that field within 'ip addr' never had any significance to IPv4 entries (and ...
- 436k
12
votes
Accepted
Subnet or Not with 20 mask?
Yes. If the subnet mask is smaller than 255.255.252.0 (CIDR /22) all devices with IP addresses 192.168.1.x and 192.168.2.x belong to the same subnet and don't need a router to communicate with each ...
- 4,574
4
votes
How routing works on Internet
So your question is awfully broad as stated, so I'll barely scratch the surface, but I think the thing you are missing is that the route is not decided in advance (in fact multiple packets in a ...
- 35.4k
3
votes
Accepted
How can I add a permanent IP routes that survives a network restart (systemd-networkd)?
It looks like you are running netplan (see second line of your log output), which creates config files in /run/systemd/network/ for systemd-networkd to use, which means your /etc/systemd/network/ens3....
- 841
3
votes
How routing works on Internet
The $30 home router does a lot less then you may think. Cutting it down to its minimal requirement it needs to
Be able to read the ethernet frame and identify the destination ip of the traffic (and ...
- 69.6k
3
votes
Accepted
Why a packet is sent with a wrong source IP address when setting fwmark using iptables mangle to change routing table?
First an explanation of what you are experiencing and why it behaves like that:
When the application generates the packet, the fwmark is not set yet. Since the application does not specify a source IP,...
- 841
3
votes
Resolving IP conflicts when connected to an OpenVPN server
Yes, extremely well known problem, and therefore it has a very proven simple solution. Renumber one of networks so they don't clash. This is by far most recommended solution and if you don't have any ...
- 2,634
2
votes
Accepted
is it possible that packet loss could be causing VoIP software to fail?
Yes and no! Its possible, but unlikely the issue here.
Packet loss CAN cause failures, but this almost certainly not the case here.
A few things to unpack first -
VOIP typically uses UDP which is &...
- 69.6k
2
votes
Why Ubuntu prefers RA route to directly connected interface?
The OS used in this issue is Ubuntu 22.04.1 LTS which is using systemd-networkd 249.11-0ubuntu3.4.
According to the man page, it should not add RA with a metric of 100. It should be 1024 by default:
...
- 131
2
votes
Accepted
How to recover connectivity to remote PC after messing IP settings sharing vEthernet (WSL) adapter to my physical one instead of the other way around
A gateway is not needed to reach addresses that are on the machine's own subnet, so you need to find a way to make your VNC connection appear as if it's coming from the router's LAN IP address instead ...
- 436k
2
votes
Accepted
Determine which IP address will be used for default route in Powershell
For PowerShell (at least the built-in PowerShell 5) you have Find-NetRoute. You do have to specify the destination you want to determine a route for, and optionally also the source address – the tool ...
- 436k
2
votes
Subnet or Not with 20 mask?
can 192.168.2.x network use the 192.168.1.1 gateway because of the 20 mask?
Yes, because they are not separate networks – both addresses are within the same 192.168.0.0/20 network.
You're too used to ...
- 436k
2
votes
Accepted
Routing WireGuard peer's traffic via another peer
The via <gw> part of your route cannot do anything here, as WireGuard is a L3 tunnel which doesn't carry any L2 (MAC) addressing inside. Instead the WireGuard interface itself selects which peer ...
- 436k
2
votes
Accepted
How routing works on Internet
But how the router (e.g. this simple router in home bought for 30$) can know all appropriate hops that will lead the HTTP request to appropriate machine?
In your case, as a residential customer – it ...
- 436k
2
votes
With Two WireGuard VPN interface clients, route dummy iface via VPN0 and normal eth0 iface via VPN1, is it possible?
Assuming you mean incoming traffic on eth0 and Dummy should be forwarded via respective wireguard ifc:
ip rule add iif Dummy lookup 100 prio 100
ip route add default via a1.a2.a3.a4 dev VPN0 table 100
...
- 76
2
votes
Resolving IP conflicts when connected to an OpenVPN server
If I connect to my home network using OpenVPN (tap, not tun) and try to access my machine on (for example) 192.168.1.197, I'm pretty sure my client won't know where to route these packets as the same ...
- 436k
2
votes
pfSense and OpenVPN client but traffic exits through the WAN interface
Now my problem is that currently all my local network traffic goes through the WAN interface, I want to send packets with a destination IP address that is in a firewall alias group through the VPN ...
- 436k
2
votes
Accepted
Ethernet device not reachable when WIFI is on
It sounds like your IoT device and your Mac's Ethernet interface are on a standalone Ethernet LAN, which is not actually connected to your larger home LAN that your Wi-Fi is attached to.
Unfortunately ...
- 103k
2
votes
traceroute does not show the network my public ip is in
The NAT gateway handling your public IP address, as well as the next-hop router beyond it, also have other IP addresses they use. Routers always have multiple IP addresses. As long as they send their ...
- 103k
2
votes
Accepted
Routing table behaviour coupled with bound sockets - unexpected behaviour
When binding to the interface, unless adequate routes are found on this interface and then reused (for their gateway), the packet is always emitted to the interface even without proper route. So this ...
- 5,497
2
votes
Accepted
Allow access from 192.168.1.* to 192.168.2.*
Your current problem is the following (in layman's terms):
Router 2 sends all destination IPs outside of 192.168.2.0/24 (or with whatever subnet mask you are using, I assume it's 24 bits) to router 1. ...
- 9,981
2
votes
Provide access to the Internet via NAT on the one router from the network separated by another router
According to mr. @u1686_grawity's recommendations in the comments, I've checked with tcpdump all the interfaces in my network topology and it appeared that there were no route to 192.168.57.0/27 on ...
- 21
1
vote
Accepted
VPN client cannot access network behind VPN server(wireguard)
The post
Can't reach networks behind Wireguard VPN server. Split-tunneligt config on client
has this answer :
Solution was quiet simple.
There is no need of any scripts to get split-tunneling.
1. Add ...
- 464k
1
vote
Accepted
access second router network from the first router
Your route seems to be correct; most likely as TomYan mentioned the problem is with the router's firewall configuration.
Practically every "home wireless router" is built with the assumption ...
- 436k
1
vote
Accepted
IP Routes to connect to every subnets in the local network
Would it be possible to create IP routes to get all the packets in my local network without changing the IP address and the subnet ?
No, routes will not help you get all the packets. They only help ...
- 436k
1
vote
How do I connect two LANs via routing?
You're likely asking for
Ethernet Bridging,
described as:
Ethernet bridging essentially involves combining an ethernet interface
with one or more virtual TAP interfaces and bridging them together
...
- 464k
1
vote
Accepted
Access Devices On Different Subnet
I'm going to assume you mislabeled the box from the ISP and that it's not merely a modem, but actually a home gateway router (with integrated modem) that does NAT and DHCP for your LAN. That is, I ...
- 103k
1
vote
Accepted
Ubuntu VM gets "destination host unreachable" for network, yet host is able to reach network
I have no idea why this was necessary or if this was the right way to go about this, but I solved it by manually adding a route:
Site A: sudo ip route add 192.168.1.0/24 via 172.20.0.1
Site B: sudo ip ...
1
vote
Accepted
Home network traffic monitoring and routing solutions?
Regarding port forwarding I came across this piece of software called ngrok, which enables me to do exactly the thing I want. My only concern is that it uses their external DNS servers in order to ...
- 436k
1
vote
Accepted
nftables: isolate VLANs with some exceptions
You really don't need any special tables or chains:
Start with the default forward chain in the default 'inet filter' table that your OS usually fills in in the distributed /etc/nftables.conf example ...
- 436k
Only top scored, non community-wiki answers of a minimum length are eligible