All Questions
Tagged with centos networking
403
questions
-2
votes
1
answer
77
views
Set a specific IP per program in CentOS
I have a VPS with multiple IPs assigned. In this VPS I run some programs that make requests on the network and, for some reason, all the requests use one specific IPv4 of my VPS.
However I have many ...
- 316
0
votes
0
answers
32
views
Configure a server to act as an internet gateway [duplicate]
I have two virtual servers hosted in Hetzner Cloud. The first server (let's call it Access Server) has a Public IP assigned and has internet access. The second server does not has a public IP assigned ...
0
votes
0
answers
90
views
How to prevent ethernet issues after command line shutdown in CentOS7?
I'm running into a frustrating issue with a system running CentOS7. There's an Intel NIC (Intel Corporation Ethernet Connection (2) I219-LM (rev31)) which, when working, provides a 1000Mb/s connection....
0
votes
0
answers
59
views
system load spikes causing php-fpm pools to fill and cause micro outages
kind of at my wits end at this point and looking for some help.
2 physical Web servers
CentOS
NGINX
PHP5
php-fpm
2 physical DB Servers
CentOS
NGINX
elastic search
zookeeper
couchbase
as user load ...
0
votes
0
answers
72
views
Wrong External IP for Real Server Behind Load Balancer
I have a hardware load balancer with multiple Virtual IPs. ie (3.3.3.3, 3.3.3.4).
Behind Virtual IP 3.3.3.3 I am load balancing several web servers.
Behind VIP 3.3.3.4 I have a mail server running ...
- 101
1
vote
1
answer
123
views
Where can I set additional conf files for NetworkManager
I am using Linode and every single time I boot my server, Linode (cloud provider) ovewrites the file below:
/etc/sysconfig/network-scripts/ifcfg-eth0
This is well documented and expected in order to ...
- 11
1
vote
1
answer
384
views
OpenVPN Client doesn't connect to my own server, but receives packets according to tcpdump
My problem is that I cant connect to my OpenVPN Server. I always get a "TLS key negotiation failed to occur within 60 seconds (check your network connectivity)" error. Running tcpdump while ...
0
votes
0
answers
110
views
A remote linux periodically lost connection
I have a Centos 8 Linux server, it will periodically lost network connection.
ping it's address, will fail for a while and recover automatically.Ping from my local machine or another remote server ...
- 151
0
votes
1
answer
296
views
Something is closing connections in my CentOS VMs - how to best troubleshoot?
I have a setup with 3 VMs (1 application server on CentOS6 and 2 database servers on CentOS7). The last 1-2 weeks we have had issues with timeouts when connecting to the database servers (and between ...
- 213
0
votes
0
answers
393
views
CentOS 8: two external network adapters, two ISPs - routing problems
Given: a CentOS 8-powered computer with three network adapters.
eth0, eth2: external, connected to two different ISPs
eth1: faces home network (intranet)
The task: allow accessing certain internal ...
0
votes
0
answers
61
views
Odd rpcbind connection
I ran rpcbind on my Centos 8 server and I noted an odd server:
rpcbind 1038 rpc 13u IPv4 46028565 0t0 TCP CentOS-82-64-minimal:sunrpc->ilijavujovic.tempurl.host:61000 (ESTABLISHED)...
- 1
0
votes
1
answer
543
views
CentOS: Redis max client connection limitation
I am using Redis caching server on CentOS, where Redis accepts clients connections on the configured listening TCP port. I am trying to figure out the limits applied by the operating system to the ...
- 137
0
votes
0
answers
319
views
Secondary network interface can't be pinged with Amazon Linux 2 AMI
Short story: both private IP addresses on primary network interface can be pinged, but both private IP addresses on secondary network interface cannot be pinged.
Long story:
Based on this aws ...
- 189
0
votes
0
answers
24
views
Cent OS not work with 2 Interface and same subnet
Please see the illustration.
OS: Centos 7
Device A tranfer file to Linux .11
Device B tranfer file to Linux .12.
Both Interface is same subnet and don't have defualt gateway.
Issue:
On interface .12 ...
-1
votes
2
answers
804
views
How can I mirror all traffic to another server?
I have 2 different CentOS servers (A and B) on different networks. How can I mirror/retranslate all traffic from all ports from server A to server B?
Server A has many runned applications that ...
- 99
0
votes
1
answer
607
views
position and override the default nftables rules
I recently installed Centos8 on a virtual machine to try nftables as a replacement for iptables.
I installed it by choosing the full server with GUI option.
With nft list rulset I have a long output ...
1
vote
1
answer
563
views
Where are nmcli capitalized setting stored and how can I modify them?
I have a VM and I'm playing with nmcli on CentOS 8
nmcli shows a couple addresses which I added. I was able to remove the .106 address from the ipv4.addresses, but not from the capitalized ...
- 15
0
votes
1
answer
5k
views
Error renaming ethernet device: 'Error either dev is a duplicate or "enp96s0f0" is a garbage'
I received these new computers that use the "eno" network naming convention. But the application I am working with is expecting the "enp96s0f0" naming convention. I am trying to ...
0
votes
0
answers
764
views
Networking not working on Docker / Centos 7.9
I'm running Docker on Centos 7.9.2009 and have a very strange issue. The containers do not have network access and cannot be accessed from the host. I've searched for potential solutions, a lot of ...
- 1
0
votes
1
answer
143
views
How to use different network interfaces for different users?
I am running a CentOS 8 server where I have a VPN interface tun0, I also have a user vpn. What I want to do now, is to make sure that the only possible network to use for vpn is tun0. For all of the ...
- 101
0
votes
0
answers
345
views
Why I can't define a DNS to docker
I will try to summarize my problem as accurately as possible. I have to install Gitlab on a machine that has CentOS 8 and install it as a docker container. So far everything was going well, I was able ...
0
votes
0
answers
56
views
How to access a host on 192.0.2.0/24 from Linux?
I've got my hands on the FSM-510G switch that has a default IP set to 192.0.2.1.
It's obviously not in the LAN CIDR block, so what should I do on a Linux host to be able to access it directly?
The ...
- 195
0
votes
0
answers
50
views
Switch to failover IP instead of main IP for all HTML requests?
I'm using Centos 8 and with my luck, my main IP is blacklisted on an API I'm trying to use.
I have 3 failover IP addresses however. Is it possible for me to use one of these failovers instead?
- 1
-1
votes
1
answer
152
views
What and how causes a system to ignore DNS settings?
I have nameservers setup in the network config file and resolv file but the system is still using root dns to look up using root servers. Could having search in the resolv file send the look up to the ...
- 3,941
0
votes
1
answer
888
views
How to setup a routing to another network from a computer which is attached to network with /32 mask
I have two CentOS 8 servers in a cloud and laptop connected via vpn.
First one is vpn server.
ip route
default via 192.168.1.1 dev eth0 proto dhcp metric 100
10.0.0.0/16 via 10.0.0.1 dev ens10 proto ...
- 1
1
vote
1
answer
714
views
How should I create an IPIP tunnel between 2 OpenVPN servers?
I have 2 CentOS 7 servers which both of them have OpenVPN installed on them . I want my clients on the first server to be able to connect to the OpenVPN server and then I want their network traffic to ...
- 33
0
votes
0
answers
1k
views
How can I accept IPIP connection in CentOS 7?
Guys I have a server with Mikrotik Router OS installed on it and there are some PPTP users using that server as a VPN server . What I want to do is to create an IPIP tunnel between this Mikrotik ...
- 33
1
vote
0
answers
1k
views
Centos 7: Cannot curl localhost nor internal IP : no route to host
Centos 7, lamp stack.
firewall is turned off, sealinux is disabled, Iptables looks fine
if you to localhost/api.php or internal-ip/api.php
from a browser, it works fine, if you ping it's fine, if ...
- 251
0
votes
2
answers
992
views
CentOS 8 network on boot
I'm running CentOS 8, every time I reboot the network does not start until I log in to the system.
I've checked the NetworkManager and the autoconnect is set to yes.
connection.autoconnect: ...
0
votes
1
answer
1k
views
What are the drawbacks/issues when having REALM and DOMAIN with different names in FreeIPA?
I have been trying to configure a FreeIPA server for learning purposes and to have centralised access to all my self-hosted services for me and my family/friends. I started with this tutorial where ...
- 131
0
votes
1
answer
194
views
Can I limit the scope of ntop to only monitor a specific connection?
I need to be able to track client data usage between their VM and an S3 compatible object storage bucket (accessed via https). I've installed ntopng community edition on the VM and right now it's ...
- 598
1
vote
2
answers
905
views
Set static IP, network service will no longer boot
I set a static IP for my CentOS 7 server using nmtui edit (edited Wired connection 1):
and now the network service (systemctl restart network) no longer boots.
Log output:
-- Unit network.service ...
- 211
3
votes
0
answers
10k
views
Server can't find domain: SERVFAIL
I have VPS and CentOS7 installed on it. Also I have httpd Apache2, nginx, named and iptables services working there. First, when I just bought this server, I had hostname maindomain1.com and made my ...
- 41
0
votes
1
answer
992
views
Packets not getting forwarded on Centos7 between GRE tunnels
I'm have configured GRE tunnels between centos machines and corresponding routing tables on individual centos machines as shown in the image:
I dont have enough reputation to post images
Router1-----...
- 3
2
votes
1
answer
7k
views
How to change the k8s internal ip addresses?
I provisioned a kubernetes cluster on my own couple of virtual machines via kubespray.
The VM's network is bridged adapter and kubespray uses calico as default network-plugin.
Before sometime, I've ...
0
votes
1
answer
587
views
Server not connecting to the internet on new CentOS install, but ethernet is connected?
In the past, whenever I have set up a new install, I haven't had to configure the IP manually, because the IP configures automatically.
Not so in this case.
This time around I took a new server and ...
user250795
0
votes
2
answers
1k
views
MariaDB Maxctrl Not Responding CentOS 7
I'm working on setting up a MariaDB 3 Node Cluster and using Maxscale as the proxy. I had set up a practice config on some local KVM machines, worked without a hitch. So I went to spin up the ...
0
votes
0
answers
268
views
Why one of my interfaces receives DHCP requests
I have a server with multiple interfaces. One [Eth_ext] is connected to external network and other two [eth0, eth1] are connected back-to-back to another server.
Say eth0 is on 10.0.0.0/24 subnet
and ...
- 101
0
votes
2
answers
481
views
Is it possible do delete routes in /etc/sysconfig/network-scripts/route-* files on Centos?
I would like to delete explicitly a route in the 'static' route configuration file for some interface ( in /etc/sysconfig/network-scripts/route-eth0 for example).
Using the 'ip route' format in that ...
- 1
1
vote
2
answers
803
views
CentOS Hyper V Guest VM Not accessible from the Internet
I have a CentOS VM sitting on HyperV host with two interfaces, One interface connected to the domain Network via a switch (192.168.1.8 /24) GW 192.168.1.254.
Another interface is connected directly to ...
7
votes
4
answers
8k
views
Why can a port can be accessible from outside although it is not in firewall open ports on centos 7?
I have a remote vps working with CentOS 7, related firewalld info is as below, firewalld is running actively.
[root@doer mydir]# firewall-cmd --get-zone-of-interface=eth0
no zone
[root@ doer mydir]# ...
- 185
0
votes
0
answers
215
views
List active sessions from tun interface
I'm running CentOS and have a tun interface with IP subnet 10.0.0.0/24 attached for "users".
Is it possible to list current active sessions with netstat, ss or similar?
Ex. netstat something:
tun-...
- 419
1
vote
3
answers
136
views
Some program is making connections to an unknown subnet, but couldn't find the process that initiates the connection
We have a server that is making a lot of outbound connections to a particular subnet, I am not able to find out what process is making it.
I could see the connections in tcdump -
[root@something ~]# ...
- 139
1
vote
0
answers
659
views
Emulex OneConnect 10Gb Network Unclaimed
As a novice im hoping to gain a helping hand, Ive recently switched from windows server 2019 over to Centos 7 and the server has a 10gb Emulex OneConnect nic / card installed.
When using windows i ...
- 11
0
votes
1
answer
53
views
Use another source address on Linux to a specific destination
I've a Linux box (CentOS 7) with one interface. Its IP is 10.10.0.2. I have an alias IP address too: 10.20.0.2. I'd like to call a webservice from the alias IP address. How can I achieve this? So add ...
- 125
2
votes
2
answers
2k
views
Realtek RTL8111/8168/8411 ethernet card randomly disconnecting
System information:
kernel: latest OPENVZ kernel (2.6.32-042stab140.4)
centos version: CentOS release 6.10 (Final)
network card type:
Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/...
- 23
0
votes
1
answer
41
views
Programs to monitor CentOS servers and workstations?
Are there programs / solutions that would allow me to monitor the hardware, software, issues, performance, networking and I/O of approximately 100 CentOS/Rhel servers and workstations?
Google finds ...
- 1,019
10
votes
3
answers
39k
views
Possible to list members of a network bridge?
When installing KVM on Fedora or CentOS it creates virbr0, but I can't see anywhere that en0 is part of the bridge.
Question
Is there are a command to see the members of a network bridge?
- 10.6k
2
votes
0
answers
184
views
Efficient parallel file transfer between two hosts using mutliple 10GbE NIC ports
I need to regularly transfer large amounts (several TBs) of video files between two servers on a 10G network. I want to decrease the overall time it takes to finish the job.
I am running CentOS7. I ...
- 155
1
vote
1
answer
4k
views
How to create network bridge for KVM with nmcli?
I used to create a network bridge on CentOS 7 as seen below, where I would disable NetworkManager and edit the config files by hand.
However I would like to do it with nmcli and therefore use ...
- 10.6k