Linux Networking refers to any networking function performed by a server running Linux. A Linux server operating as a router or firewall are the most common applications.

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4
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2answers
25 views

How do I set up docker containers to communicate on private network?

I have a small cluster at rackspace with a private network in the range 192.168.3.0/24. I would like my worker services to talk to each other using this network but can't figure out how to get docker ...
0
votes
1answer
850 views

IP setting in CentoOS 6.2x64 by XenCenter 6.2

I have setup a Guest CentOS virtual machine in Xenserver.. I have updated the Xentools but i cannot find the option to config my IP Address which is showing to be 'unknown' currently. All i need to do ...
1
vote
2answers
1k views

Untangle VPN setup, how to see internal addresses?

So Untangle is setup as the default gateway at 192.168.100.1/24, it is the authorative DHCP server issuing addresses from 192.168.100.100 to 192.168.100.200 and is successfully connected to the ...
1
vote
1answer
32 views

How do I block incoming traffic from Amazon AWS IPs?

I'd like to block ALL incoming traffic from Amazon AWS IPs. They publish a list of their IP addresses in json format here: http://docs.aws.amazon.com/general/latest/gr/aws-ip-ranges.html I have a ...
1
vote
1answer
19 views

Dummynet Filtering not working on FreeBSD 10

I am trying to do network emulation using dummynet in FreeBSD 10. I have this working in 9.3 however things must have changed and I cant determine exactly what but my setup no longer works. I have ...
11
votes
2answers
5k views

PXE Booting Virtualbox guests in internal networking mode?

I am not sure if this is just specific to my distro's packages or is a vbox limitation. So, any help would be appreciated. Ok, so I have a network of VMs, with one VM acting as a NAT for the other ...
0
votes
1answer
31 views

conflict in network interface configuration of CentOS 6.5

I am trying to create 2 network interfaces, one with DHCP and the other with static IP on a CentOS VM running on ESXi Server. Content of file ifcfg-eth0 is as follows: DEVICE=eth0 ONBOOT=yes ...
0
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0answers
23 views

OpenVPN server cannot ping client (routing/iptables issue?)

I am not sure exactly where the issue is here. I'm fairly sure that this is some NAT or iptables issue on the OpenVPN server but am lacking the networking know-how to fix the issue. The crux of the ...
1
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0answers
42 views

linux not replying to an arp request

I am running linux 3.14 on a system with 2 interfaces. on the first interface, i can access our local network. on the second interface, arp packets come in but linux doesn't send out reply. is it ...
1
vote
1answer
34 views

Is Linux limiting my application's UDP transfers, and how can I see it?

I am currently developping two applications to work over a custom video streaming "protocol". Basically: The server captures video frames from a webcam, slices them into parts, and sends these parts ...
10
votes
6answers
19k views

Delete a iptables chain with its all rules

I have a chain appended with many rules like: > :i_XXXXX_i - [0:0] > -A INPUT -s 282.202.203.83/32 -j i_XXXXX_i > -A INPUT -s 222.202.62.253/32 -j i_XXXXX_i > -A INPUT -s ...
0
votes
2answers
12 views

Is it possible to configure carp using /etc/network/interfaces?

Lots of tutorials out there show to set-up carp using ifconfig: https://www.netbsd.org/docs/guide/en/chap-carp.html I'm wondering if it's possible to do the same using /etc/network/interfaces? For ...
5
votes
1answer
90 views

Load balancing network traffic using iptables

I am trying to load balance traffic from internal LAN on a linux router having two gateways. Initially I went for the iproute implementation which didnt balance the load as expected, reason being that ...
-4
votes
1answer
25 views

Common ethernet settings for UDP when bandwidth usage is high [on hold]

Suppose I have lot of servers which TX and RX lot of UDP traffic. Suppose I have 100 Mbps ethernet to use to TX or RX around 80 Mbps UDP traffic. And suppose I have 1 Gbps ethernet to use to TX or RX ...
1
vote
2answers
61 views

Performance Tuning Linux [closed]

Performance Tuning/ Monitoring/Latency keeping in mind I see following 4 items & in each item they are lot of tools. CPU Memory IO Network What I see following tools we do use. vmstat mpstat ...
1
vote
1answer
2k views

Error while bringing up eth1

I'm getting this error while bringing up my network card: (process:2550): WARNING **: _nm_object_get_property: Error getting 'State' for /org/freedesktop/NetworkManager/ActiveConnection/3: (19) ...
-1
votes
0answers
35 views

syslogd is attached to a remote IP address

I have a hosted server and I have 3 VM's on the server. I did a netstat -antup and noticed this: tcp 0 0 192.168.0.15:37023 73.167.119.19:21333 ESTABLISHED 4039/syslogd Does this ...
0
votes
0answers
7 views

promisc mode doesnt work - better solution?

I have a Debian Wheezy server running snort with two network cards: eth0 and eth1. Eth0 is used to recieve a packet stream to inspect by snort - while eth1 is used by the admin to connect to the ...
1
vote
2answers
41 views

Can't connect to MySQL from another server

I have two servers on the same subnet. 192.168.100.1 (mysql) 192.168.100.2 (php) MySQL seems to be running fine on it's box but I can't seem to connect to it. These are both ubuntu boxes and ...
0
votes
1answer
27 views

Stale Network connections to Tomcat AJP port

I have Tomcat Application server connected with Apache server using mod_jk connector. Both are running on different servers. Apache ----->------ Firewall ----->------ Tomcat For the last couple of ...
1
vote
0answers
5 views

Virtualbox: Incoming connections from arbitrary networks to VMs in host-only network appear as if originating at the gateway [migrated]

Configuration: Ubuntu 14.04 host Virtualbox 4.3.18 (from http://download.virtualbox.org/virtualbox/debian ) Ubuntu host functioning as a router - net.ipv4.ip_forward=1 Several host-only networks ...
1
vote
1answer
52 views

Redirect all traffic from multiple interfaces to single IP

I would like to redirect all traffic (specifically TCP & UDP) from multiple WAN interfaces (ppp0, ppp1, ppp2) to a single IP from eth0. When it comes to interface to IP, I can use the PREROUTING ...
0
votes
1answer
22 views

IPsec transport mode and MTU

[Similar to Right way to set the MTU of an IPsec Client (Linux/Racoon), but different in that there is no router on the responder side] I have a setup where machines in a local network need to talk ...
4
votes
5answers
428 views

Arbitrary VLAN interface name

Is there a way to name a VLAN interface arbitrarily like eth72 or ext19 instead of the four standard nameing schemes eth0.72, vlan19 (and the padded variations)? Don't have no clue. Perhaps udev?
0
votes
1answer
55 views

Using Firewall-cmd to create address specific restrictions in centos 7

How do I create a firewall rule using firewall-cmd tool (new firewalld) such that I will limit specific network to access only one service and allow all on all service in one zone. For example: I ...
-1
votes
0answers
22 views

Nginx response latency different on different port

I have two server connected to a same SW(HUAWEI S5700) with 1Gb link. I deployed nginx on one server and try to retrieve file from it in another server. In nginx I have two server configuration with ...
-1
votes
2answers
528 views

Why can't I add two '…-m recent --update --hitcount…' rules to iptables chain?

To stop brute force attacks on my server (OS is CentOS 6) I want to block for 1 minute everyone who makes more than 4 login attempts during last minute block for 1 day everyone who makes more than ...
-1
votes
1answer
30 views

How to check what application is requesting port? [duplicate]

Is it possible to check which application is requesting specific port in a debian server? I'm getting a ton of these in iptraf: x x UDP (77 bytes) from 172.16.0.2:25748 to 212.59.1.1:53 on eth0 ...
1
vote
1answer
76 views

bacula backups very slow with TCP socket in 'unkn-4' state

Several bacula-fd clients are backing up to one bacula SD (using 2G disk files on massive RAID, not tape), usually 2-3 of them concurrently. It works fine, except when 2 bigger clients (about ...
0
votes
2answers
89 views

Intermittently high ping times to router via Wi-Fi

On my local network there are (among others) 5 machines (running Debian Jessie or Arch) wirelessly connected to a Netgear WNDR4000 router. Below is a graph of the ping times to the router from each of ...
1
vote
1answer
21 views

Windows network failing, not present on linux clients

got a really strange one for you all. I have a network setup using a linux machine as a gateway between various network segments (on seperate nic's) and virtual machines (one of which is a mail ...
0
votes
2answers
15 views

Bind dont forward to secondary dns server as specified in “forwarders” under named.options.conf

I have bind9 setup to forward dns queries to machines connected localy trough the 192.168.1/24 network. The ip's that I forward the queries to are also my internet gateways. Sometimes one of the ...
0
votes
1answer
94 views

VMs on ESXi system, only able to use internal IPs

first off I am a bit of a network newb, I know the basics but that is about it. So I have a ESXi server running a few VMs. The set up is; -Master IP (controls the ESXi box) -Internet IP (for general ...
1
vote
0answers
40 views

Route traffic for a specific IP through a specific interface

I'm setting up a server that tunnels all its traffic over an OpenVPN connection. The VPN connection is further tunnelled over obfsproxy hosted on the same machine. The problem is that as soon as the ...
2
votes
2answers
51 views

IPv6 Stateless Autoconfiguration route advertisements

In our network, we have a Cisco router acting as the core router, connecting all our sites to the main site. We also have a Linux firewall connecting us to the Internet. Site 1 --\ ...
0
votes
1answer
24 views

nmap: why is it scanning port 80 with TCP ACK and not SYN?

While reading nmap man pages, I read for the -sn option: The default host discovery done with -sn consists of an ICMP echo request, TCP SYN to port 443, TCP ACK to port 80, and an ICMP timestamp ...
0
votes
0answers
15 views

Dropped TCP Packets over two-stage IKEv2 VPNs

Something of a weird setup this: There are two Virtual Private Clouds (10.100.240.0/20 = prod1 and 10.101.0.0/24 = control), which have a valid router between them. Control hosts a VPN that is meant ...
1
vote
0answers
14 views

Configuring openldap/PHP LDAP against “signed” LDAP connections with Active Directory

This may sound like a stupid question, and maybe it's already been answered, but I can't find a definitive answer anywhere, so I thought I'd ask. When someone enables "Domain controller: LDAP server ...
-1
votes
0answers
46 views

How to fixe codeigniter 404 Page Not Found in linux hosting

I have .htaccess as below code # Set PHP Time Zone: #SetEnv TZ America/New_York <IfModule mod_rewrite.c> #Option +FollowSymlinks RewriteEngine On RewriteBase / RewriteCond %{REQUEST_FILENAME} ...
1
vote
3answers
1k views

Configure a Linux router for fair bandwidth allocation without unnecessary limiting it

I run a Linux router (more precisely OpenWRT) on an internet connection with very limited bandwidth, around 1 MBit/s downstream and some dozen kBit/s upstream. There are several machines on the net ...
0
votes
2answers
1k views

How to route broadcast packets from machine with two network interfaces on same subnet

I run RHEL 5 and have two NICs on one machine connected to the same subnet: eth0 192.168.100.10 eth1 192.168.100.11 My application needs to receive and transmit UDP packets (both unicast ...
2
votes
3answers
2k views

How can I achieve OpenVPN client routing without NAT on Linode

I've set up an OpenVPN network, and it is working properly in the sense that I can access the inner/LAN machines from the remote client. However, my problem is that all traffic from the remote ...
1
vote
2answers
56 views

SSH works locally but not remotely

Recently ran into a hardware issue on my CentOS machine. After a PSU, ram, mobo and CPU replacement I think I have the hardware issue resolved. However, I believe I have a network configuration ...
2
votes
1answer
174 views

Passing through RDMA network devices to docker containers

I'm wanting to passthrough infiniband to a docker container so that I can run some high performance apps over ipoib and use rdma. Currently, I'm doing this with xen virtual machines. Now I'm looking ...
0
votes
1answer
26 views

Hosts cannot ping in two name spaces using Open Vswitch

I have two name spaces red and blue. Red is connected to host1, and blue is connected to host2, but these two hosts cannot ping each other. Here is the commands that I put: ip link add host1 type ...
0
votes
0answers
15 views

how to use public ip in my private network [migrated]

I'm trying to use public IP address in my private network. In a short, how to set public IP, which is different to endpoint IP of my private network, to my server in my private network? Is other ...
0
votes
2answers
44 views

Port forward with iptables

I got lo (127.0.0.1) and eth0 (172.17.0.8). I want to redirect packets that land on 127.0.0.1:80 to 172.17.42.1:80 (route from eth0). I tried iptables -t nat -A OUTPUT -p tcp --dport 80 -d 127.0.0.1 ...
0
votes
0answers
4 views

linux: how to troubleshoot forwarded port? [migrated]

My home internet connection has a static IP address (eg: 123.123.123.123) I have configured my router to forward port 9000 to an internal host (192.168.1.101). That host is running Ubuntu 14-04. ...
1
vote
2answers
71 views

Add a VLAN tag to specific UDP port traffic

I'm running an application in Ubuntu12.04 that I've written that does some remote switch management. I have only a single NIC connected to the network of managed switches, eth0 which is set with IPv4 ...
0
votes
0answers
15 views

OpenVPN Client recieves reply from Ping to Server but not from eth0 or non-server IP

I have been using OpenVPN succesfully with Layer2 bonding for over a year now. I have been experimenting with a more complicated setup on the local LAN using a ProxmoxVE hosting KVM VM as the server ...