Questions tagged [iproute2]

iproute2 (ip) is a tool used to manipulate network configurations.

Filter by
Sorted by
Tagged with
0 votes
0 answers
23 views

How to access Public VM IIS from internet in AZURE?

I have below things: 2 VM inside 2 subnet all are in Vnet1. VM1 has enable IIS, VM1 and VM2 Assign public IP. VM1 has assign public IP and I need all traffic from public IP of vm1 from VM2. INTERNET &...
user avatar
0 votes
1 answer
23 views

Why "vlan: 3 parent interface: en0"

I have created a VLAN: Linux vconfig add en0 3 ip addr add 192.168.126.5/24 dev en0.3 ip link set up en0.3 can be translated to macOS by e.g. MacOS ifconfig vlan0 create ifconfig vlan0 vlan 3 vlandev ...
user avatar
  • 145
0 votes
1 answer
70 views

List "hardware" Network Interfaces Controllers

When using ifconfig or ip link show commands, it lists not only hardware interfaces, but also software interfaces - I would expect only the physically interfaces? Note: I am running on MacOS. ip link ...
user avatar
  • 145
0 votes
0 answers
178 views

Wireguard networking issues

I'm having some wireguard networking issues and hope you guys can help me. My goal is to build a side to side vpn. For that I have host A (public) and host B (private). Below is my config to create ...
user avatar
2 votes
2 answers
106 views

In Linux how to add a route to a prefix via a specific device with certain destinations in that prefix going via default route?

I'm currently dealing with a VPN which connection endpoint lies within the subnet which prefix shall be tunneled via that specific VPN. Essentially the problem thus boils down to match against a (...
user avatar
  • 259
0 votes
1 answer
44 views

Redirect specific traffic through a VPN interface

I, I would like to redirect specific ports through a specific interface. Until now what I accomplished it was cat /etc/iproute2/rt_tables | grep "200 force.route" > /dev/null if [ $? != ...
user avatar
0 votes
1 answer
55 views

Send response back through same device for connections coming in through Wireguard

I have a server lanserver running in my private LAN that is connected to a public server publicserver using Wireguard. publicserver forwards TCP connections to certain ports to lanserver through the ...
user avatar
  • 841
0 votes
1 answer
162 views

Why I get "cache" in the output of `ip route get`?

I'm using kernel 5.11.0 and in the ip-route manual [1] it can be read: Starting with Linux kernel version 3.6, there is no routing cache for IPv4 anymore. Hence ip route show cached will never print ...
user avatar
0 votes
1 answer
102 views

Unable to use fwmark on Debian 11 (bulleyes) to change routing behavior

I have a recipe I already use on many cases, but this time doesn't works on Debian 11 (kernel 5.10.0-10-amd64) my setup is basically an internal interface eth0 for a RFC1918 LAN, and two external ...
user avatar
  • 356
0 votes
1 answer
250 views

Force new process to use the specific network interface (using netns/network namespaces)

I have a number of interfaces available on Ubuntu 20.04 machine. Among others enx0c5b8f279a64 and usb0 with the later being used as the default one. I want to make sure that a particular process ...
user avatar
  • 11
0 votes
1 answer
215 views

Ubuntu server as both a private NAT router and a public router

I am attempting to do something I've never tried before. I have a Dell PowerEdge 540 that I've installed Ubuntu on. I got a Comcast Business line installed, and have the following physical network ...
user avatar
0 votes
0 answers
15 views

iproute2 policy route same subnet wrong ttl value

I have a Linux PC has two NICs: 1st name is ens192, ip is 192.168.0.2/24 gw is 192.168.0.1 also default route, major NIC 2nd name is ens256, ip is 192.168.1.50/24 gw is 192.168.1.1, and with follow ...
user avatar
0 votes
0 answers
93 views

How to mark and separate connections?

I have a issabel Linux (based on Centos 7) with 3 ethernet, and I want this scenario: eth0 with IP 172.16.3.30/16 ----gw(172.16.0.1)----> (I want to use as Default Gateway) eth1 with IP 10.1.5.102/...
user avatar
0 votes
1 answer
59 views

How to switch linux interface to trunk-only mode?

I'm trying to configure linux interface into trunk-only mode, that means 'accept only vlan-tagged traffic', and most importantly, ignore all untagged traffic. I'm pretty successful at having tagged ...
user avatar
0 votes
1 answer
152 views

how to mark connections to route multiple gateways?

hi i am having trouble setting up permanent routes for my network interfaces, i have : os : linux (centos 7) eth0 : IP 172.16.3.6 -- Gateway : 172.16.0.1 eth0:1 : IP 10.1.5.102 -- Gateway : 10.1.5.101 ...
user avatar
2 votes
1 answer
394 views

Linux: What causes static ARP entries to flush on link down

This is a question about a difference in networking behavior between Debian Buster (kernel 4.19.0-18) and Debian Bullseye (kernel 5.10.0-9). On Buster, proxy arp entries survive if the link on the ...
user avatar
  • 1,680
0 votes
1 answer
78 views

How to add a routing rule that only match "dport"?

In my OpenWrt box, I want to route only a specific protocol(tcp:1888) to a tun interface only for one PC(192.168.28.2), so I do as following: ip rule add from 192.168.28.2 dport 1888 lookup 123 ip ...
user avatar
  • 137
0 votes
0 answers
141 views

How to configure new (DHCP configured) interface with non system default route using systemd/networkd?

I am trying to configure Linux system, so during boot/adding new modem (visible as usb0 interface ) any software binding to modem interface (usb0) IP# will use offered by modem GW/routing instead of ...
user avatar
  • 1
0 votes
1 answer
30 views

Within a gateway node how to route traffic to the outside world via a specific interface consistently?

I have linux ec2 instances with two nics (eth0 and eth2). Both the nics have public ip's attached to it and are able to get out to the internet. This linux instance is acting as a gateway node for me, ...
user avatar
0 votes
2 answers
161 views

How do i modify route tables in EC2 instance to send traffic via eth1?

I have an ec2 AmazonLinux2 instance. It has a primary nic on eth0. I went ahead and attached another eni (with an associated public ip) eth1. I would like to make sure that I can send traffic via the ...
user avatar
0 votes
0 answers
24 views

Clients couldn't query DNS server listening on router interface's secondary IP

I have a router where its interface has two IPs $ ip addr br-lan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000 link/ether <MA> brd ff:ff:ff:ff:ff:ff ...
user avatar
  • 167
0 votes
0 answers
75 views

default route does not work

root@kolla02:~/dev-env# ip r s default via 192.168.1.101 dev eno1 10.0.0.0/16 dev eno2 proto kernel scope link src 10.0.0.1 10.1.0.0/16 dev virbr2 proto kernel scope link src 10.1.0.1 10.230.0.0/16 ...
user avatar
2 votes
0 answers
85 views

Routes in route6-eth0 don't apply [closed]

I made a file /etc/sysconfig/network-scripts/route6-eth0 with the following contents: default dev eth0 src ****:****::**** metric 50 pref medium However, it doesn't show up when I execute ip -6 route:...
user avatar
  • 21
1 vote
0 answers
362 views

Two instances of Dante proxy server with two interfaces

I'm running 2 instances of Dante server on my Linux machine, one of them is called danted which is supposed to connect me to the internet through the ethernet cable and the other is sockd which is ...
user avatar
  • 85
0 votes
1 answer
51 views

Auditing specific route table operations

Does Linux have a way to audit operations run against a specific route table? I have the following config in my custom route table: default dev tun0 scope link 192.168.100.0/28 dev eth0 scope link ...
user avatar
  • 205
1 vote
0 answers
121 views

IPv6 multipath routing with configurable weight

With Linux kernel 4.14, when I add IPv6 multipath routes with weights (10 & 30), they are getting added with same weight '1'. IPv4 route does not have this issue. I checked with exact same steps ...
user avatar
0 votes
1 answer
389 views

ipsec xfrm esp routing

i need a little help/explanation why the following netsetup is not working: PC1 (192.168.66.1) <-- PLAIN --> (192.168.66.2)PC-GW(192.168.88.2) <-- ESP --> (192.168.88.1) PC2 I can send ...
user avatar
  • 3
1 vote
1 answer
2k views

Change an active slave of Linux network bonding interface without ifenslave command

Linux supports bonding of multiple Ethernet network interfaces for extra reliability or load balancing. Bonding driver used to be configured via ifenslave command, which has been deprecated (...
user avatar
0 votes
1 answer
31 views

CentoOS and IP RULE

I don't understand my situation. I have a network lab like on a picture. I can't ping 192.168.5.1 from 192.168.1.2 then the 192.168.5.1 has 192.168.4.2 like a default gateway. Linux# ip route default ...
user avatar
2 votes
1 answer
191 views

How to force `ip route get` to ignore a specific device?

How can I do ip route get, but force it to ignore a specific device? When I start my VPN, I run ip route get <vpn_server_ip> to determine what interface to use to connect to the VPN. Then I add ...
user avatar
2 votes
0 answers
141 views

WireGuard Failover for MySQL Galera Cluster

I'm setting up four servers across four locations in an attempt to create a geo-redundant MySQL Galera cluster. Two of the servers are behind NAT, and I'm currently attempting to use WireGuard to ...
user avatar
0 votes
1 answer
1k views

How to bridge an internal network interface to an OpenVPN tun/tap device

I'm using a two-VM setup wherein the first VM, machine A, has a closed, private LAN shared with the second VM, machine B, which has a second network interface that is configured to hit the internet. ...
user avatar
1 vote
1 answer
76 views

ss --events no output on CentOS 7

I try to monitor continously TCP connections on a CentOS 7 box with the ss utility. If I start ss --events I recieve no events. Is there any trick to enable this? Or is the kernel (3.10) in CentOS 7 ...
user avatar
  • 13
0 votes
1 answer
299 views

Linux internet default gateway + VPN default gateway

I'm currently using a barracuda vpn client to connect to a vpn, which sets a default gateway for the vpn, routing all traffic through it. I've read about iproute2 and secondary routing tables, but my ...
user avatar
0 votes
2 answers
758 views

Can't ping between interfaces on one device on the same network

There is a device, let's call it 1, on network A Device 1 has two interfaces, eth5 and eth7 There is a device 2 on network A Pinging from eth5 to device 2 works Pinging from eth7 to device 2 works ...
user avatar
1 vote
2 answers
39 views

Process that adds hosts as unreachable

I have been troubleshooting an issue where users could not connect to a CentOS 7 server from a particular host. I eventually determined that the system considered the requesting host to be unreachable,...
user avatar
  • 11
3 votes
1 answer
585 views

Reading back Linux gre[tap] local/remote address

With iproute2 on Linux, gre/gretap interfaces are setup with ip link add, which for GRE needs remote and optionally local attributes specifying the endpoints. However, I can't find any way to read ...
user avatar
2 votes
2 answers
1k views

How to retrieve the routing tables in JSON format (linux)?

The ip command is able to return some of its results in JSON format, but it seems to be unable to format the routing table(s). Here are some examples of what I mean. List of all addresses: ip --json ...
user avatar
0 votes
1 answer
2k views

NetworkManager adding extra default gateway

Using NetworkManager, I am trying to setup multiple interfaces on different VLANs; the primary interface, em1, is used on a development VLAN; the secondary interface is on a dedicated iSCSI VLAN. I am ...
user avatar
0 votes
1 answer
58 views

Routing between two networks

Basically I would like to know what should I do to connect two PCs in different networks and make them to see each other. The diagram is like the following linux-pc-1-1 (192.168.0.2 eth0) <---> (...
user avatar
0 votes
1 answer
2k views

Unable to Configure WireGuard to Use Secondary IP Address Instead of Main IP Address of the Server

The Setup The main ethernet interface of my server is enp8s0, has one public IP address (116.202.221.254—server's main IP address), and here's how it is set up. # ip addr show enp8s0 2: enp8s0: <...
user avatar
  • 195
0 votes
0 answers
127 views

how to apply TC htb class to each of IPs in an IP range separately?

I use HTB for TC and mark packets with iptables. First I mark a range of IPs (like 192.168.1.0/24). Now I want to apply a htb class to each of these IPs separately. If I add a class and a filter for ...
user avatar
0 votes
1 answer
192 views

OpenVPN Server on a Multi-WAN Router

I have a OpenVPN Server on a MultiWAN Router (Ubuntu Based). The Problem is, that incoming packages not leaving the same WAN interface where they entered. I tested already with iptables MARK rules in ...
user avatar
  • 177
0 votes
1 answer
324 views

gretap tunnel return traffic not being handled

I'm using iproute2 to add a GRE layer 2 tunnel with a vlan tag as shown below. ip link add name gre1 type gretap local 10.0.0.2 remote 8.8.8.8 ip link add name gre1.100 link gre1 type vlan proto 802....
user avatar
  • 191
1 vote
1 answer
5k views

Response packet on the same interface as incoming in LAN

Currently, I'm struggling with the following scenario: I have a server with 2 interfaces in 2 separate LAN subnets. IF1, IF2 I have a laptop which has an IP address from the first subnet When I try ...
user avatar
  • 141
4 votes
1 answer
572 views

How is Netflix tracking that I'm behind a VPN?

Disclaimer: This is not a "I need VPN to surf Netflix". Surfing without VPN at this site allows Netflix. The question is instead the other way around: "There is a PC that needs to Internet through ...
user avatar
  • 1,679
0 votes
0 answers
49 views

Unable to change link-local address for tunnel with iproute2

I have a couple of HE sit tunnels on Ubuntu 18.04 box. Only first one works as expected and I suppose the reason is almost same link-local addresses (generated from same MAC). What I'm trying is to ...
user avatar
  • 1
1 vote
1 answer
716 views

IPsec tunnel between 2 remote host

I'm using mininet, I have created a ESP tunnel between two machine such that if I ping from one machine to other then I am seeing ESP packets, and everything works fine. Here below the commands used: ...
user avatar
2 votes
1 answer
4k views

Ping does not work on TAP interfaces with bridge

I am trying to understand the linux bridging and local ip rules, I have following topology on my linux laptop. br0 ___________|__________ | | |tap0 ...
user avatar
  • 123
2 votes
0 answers
481 views

How to group interfaces for the purpose of using ip-rule's suppress_ifgroup feature?

I found out about ip-rule's "suppress_ifgroup X" feature which seems to allow me to tell the kernel to ignore a route from the given table with an outgoing interface that belongs to that group X. But ...
user avatar

1
2 3 4 5