1
vote
2answers
285 views

Low latency TCP settings on Ubuntu

There is a server for measurements running on Ubuntu in my lab . And there is C program, which receives data through TCP connection and should as soon as possible send a reply. Network latency when ...
0
votes
1answer
25 views

iptables and TPROXY support

I'm running iptables v1.4.21 on Ubuntu 14.04 and is trying to setup iptables to use TPROXY. How can I check whether my current build of iptables supports TPROXY? I can check TPROXY support for ...
0
votes
0answers
76 views

TPROXY Not working with HAProxy, Ubuntu 14.04

I'm trying to use HAProxy as a fully transparent proxy using TPROXY in Ubuntu 14.04. HAProxy will be setup on the first server with eth0 111.111.250.250 and eth1 10.111.128.134. The single balanced ...
0
votes
1answer
45 views

Limit on IPs assigned to one interface

I have a unique application where I need to use many IPs on one server. Will Ubuntu networking crash if I assign 2048 IPs to one eth0 interface?
1
vote
0answers
139 views

Ubuntu 14.04 KVM Host - Only network device pcnet working

I've installed a KVM host on Ubuntu 14.04. I've added a networking bridge as br0 and also added the p4p1 network adapter to it. My problem is now that only the "pcnet" networking guest driver is ...
0
votes
0answers
39 views

Ubuntu refuses to route packets for public subnet through linknet

I've run into the novel concept of routing through a linknet from my new ISP, and am currently trying to get a /28 routed properly on my Ubuntu 13.10 server. However, this is proving futile. This is ...
0
votes
0answers
4 views

Poor performance with Ethernet Network Card when transferring files [migrated]

I am having a performance issue I have not been able to solve and hope you guys can help me with it. I bought a NanoPC (small computer with ARM processor) and I have it running Ubuntu 13.10. It has a ...
0
votes
1answer
39 views

Azure outbound communication

I'm having outbound communication issues on Ubuntu machines on the Azure service. I've setup the server using Ubuntu 14.04 (also tried 12.04) and I have no trouble SSHing into the machine or browsing ...
1
vote
0answers
124 views

Haproxy using 10GB Memory and 100% CPU with 50k connections

On a Ubuntu 14.04 x64 server, Haproxy uses 3.3 GB of memory and 6.8 GB of swap, while handling 52k connections. The CPU usage also keeps spiking to 100% before most of the traffic was redirected to ...
1
vote
0answers
42 views

ping: sendmsg: Operation not permitted (sometimes)

On a Ubuntu 14.04 running Haproxy, after a service haproxy reload, Haproxy is suddenly reporting all servers behind it as down. After some digging around, I noticed that ping is not working properly, ...
2
votes
1answer
330 views

Weird network problems with Vagrant, VirtualBox, Ansible and Ubuntu Server box

We are using Vagrant and Ansible to provision VirtualBox machine. It was working great, but recently we've started to encounter some weird network problems with tasks that require access to the ...
0
votes
2answers
65 views

Bind9 - local configuration is it important

I have a dedicated server and i have DNS and web server on the same server. To configure the DNS i have used BIND ... BIND comes with default configuration for localhost like 127, 0 , 255 and ...
-1
votes
2answers
36 views

Forward Clients to New Server using iptables

Clients are connected to a server A by connecting to the domain name address www.example.com:4444, where www.example.com resolves to the IP address of server A. Question: In order to provide a ...
1
vote
1answer
32 views

LXC networking not giving outgoing connection

I have a LX container on Ubuntu 13.04 which has worked flawless for the last 161 days. I restarted the host and started all the LXC's and I'm allowed to connect to the LXC containers from the outside. ...
-8
votes
2answers
85 views

512 IP in one NIC - ubuntu - is this possible? [closed]

Let's say that I have 1 network card and 2 blocks /24 of IP to assign: 150.50.50.0/24 150.60.60.0/24 I know, that I can only add 256 virtual interfaces to each NIC from ...
-3
votes
1answer
50 views

Keeping your server safe [closed]

I have a typical vps server with some custom sites on it running on port 80, a mail server, I don't have a DNS server and it is a default ubuntu 12.04. I don't have any admin panel, I am doing all the ...
0
votes
1answer
33 views

Prevent TCP Connections from Timing out on Restarting Service

On Ubuntu 14.04, an app communicates with clients at intervals of about 1 per sec to 1 per min. However the service have to be restarted regularly and this causes all the connections to drop/timeout. ...
0
votes
1answer
145 views

How to use both bonding and bridge?

I have a server with two network adapters. I configured bonding and it works. Here's the working configuration: auto lo iface lo inet loopback auto eth0 iface eth0 inet manual bond-master bond0 ...
0
votes
1answer
206 views

Tomcat & Java not listening on IPv6

We've got a webserver running Ubuntu 12.04 LTS, Tomcat 7 and Oracle Java. So far, we have been serving a web app on IPv4 address on ports 80 and 443 (80 redirects to 443). I'm trying to make the ...
1
vote
1answer
298 views

Wildfly 8.1.0 Final freezes (keeps connections forever / Channel was closed mid chunk)

I have just migrated an application from JBoss 7.1.1 to Wildfly 8.1.0 Final. But now from time to time (like every 2 days) Wildfly freezes, and I have to restart it. My application is basically ...
9
votes
1answer
762 views

Networking doesn't initialize properly when pxebooting Linux Mint (live CD) using cifs, but works with nfs

I have a TFTP/DHCP/NFS/SMB server (Ubuntu server 12.04 LTS) on 192.168.26.1. I use pxelinux to display a menu containing startup and installation options for Windows, an Ubuntu network installer, and ...
4
votes
1answer
78 views

Very High Network out in ec2 instance

I launched an ubuntu-14.04-64bit instance in Amazon EC2 two days back. And I started Tomcat 7.0.54 in that instance and deployed my application war files. It has no other software installed other than ...
0
votes
1answer
24 views

How to restrict all services to single domain in Ubuntu?

Someone has pointed an unknown domain to my server's IP address likely via A records. I would like to reject access to ALL services (httpd, ssh, mail, etc.) from this domain and only allow requests ...
0
votes
1answer
43 views

KVM Dynamic Rate Limiting

How can I dynamically rate limit the network speed on individual KVM instances? For example, I want to set a rule where if a user uses over 100mbps inbound or outbound bandwidth for over 30 minutes, ...
1
vote
1answer
186 views

Linux - Only first virtual interface can ping external gateway

I created 3 virtual interfaces with different mac addresses all linked to the same physical interface. I see that they successfully arp for the gw and they can ping (the request is coming in the ...
1
vote
0answers
1k views

Ubuntu 12.04/14.04 - apt-get 404 Not Found [IP: local-dns-server-ip 80] through proxy

I am trying to setup an ubuntu server (12.04 or 14.04) and have installed the server image onto the system I am using. Everything works fine until I try to run sudo apt-get update. When this runs, I ...
3
votes
2answers
296 views

Assign fixed IP address via DHCP by DNS lookup

Preface I'm building a virtualization environment with Ubuntu 14.04 and LXC. I don't want to write my own template since the upgrade from 12.04 to 14.04 has shown that backwards compatibility is not ...
0
votes
1answer
81 views

Why don't mails show up in the recipient's mailspool?

I have postfix dovecot running with local email system on thunderbird. I have two users on by ubuntu, mailuser 1 and mailuser 2 whom i added to thunderbird. Everything went fine, except the users dont ...
2
votes
1answer
88 views

Can I use NAT64 to route public IPV6 traffic to internal IPV4?

I have a bunch of public IPv6 addresses and some services that run IPv4 only. Can I use NAT64 to connect these services? Is there another solution like a proxy or something?
1
vote
1answer
141 views

Ubuntu 12.04 randomly dropping network connections

Good day, Few days ago I've installed new server on Ubuntu 12.04 and migrated all my data and services to it from an old one (pretty outdated 2011 year server). There are many different services ...
0
votes
0answers
46 views

OpenVPN identical subnets for client & server

I have an OpenVPN server (Ubuntu 14.04 routed mode) on a local network with a subnet of 192.168.0.0/24. The subnet it uses is obviously a very common subnet. My problem When a client is out and ...
1
vote
1answer
600 views

Ubuntu 14.04 getting ping: sendmsg: Operation not permitted

The problem is out of my league apparently, Ubuntu cannot access any network but somehow my VMs using virtual box are all able to access the internet. I have attempted to do the following changes but ...
1
vote
1answer
103 views

Split tunneling through two VPNs simeltaneously

I want to run two OpenVPN client instances on an Ubuntu Server 14.04. I have both .conf files that can work independently (both are set to different interfaces - tun0 and tun1). I want to run both at ...
2
votes
1answer
831 views

Changing the default gateway, multiple NICs

I have Ubuntu 13.10 (kernel 3.11.0-19-generic). On startup, the network configurations are as follows: dor@ubuntu:~$ sudo ifconfig -a em1 Link encap:Ethernet HWaddr 44:37:e6:4c:ca:0a ...
-4
votes
2answers
47 views

How to manage PING replies? [closed]

How can I manage, for example, my Ubuntu mashine so it doesn't (or does) respond to PING(ICMP ECHO_REQUEST - type 8) requests? Normally almost all computers in a LAN network responds to ping with an ...
0
votes
1answer
26 views

apache how to know if a download/upload is being processed

We've a web server used for heavy uploads/downloads (may take minutes). For doing maintenance disruption, we'd like to know if downloads/uploads are being processed at the current time. The things ...
0
votes
1answer
203 views

Can't connect to 2 different Linux computers via VNC (local network)

I have a problem connecting to Vino VNC server with 2 Linux Computers running Xubuntu. The computers are Based on the ODroid U3 chip which is ARM based. When both of the ODroids are on the same ...
-4
votes
1answer
48 views

Single machine server with many operating systems [closed]

Could possibly with single one high end Server with supported Virtualization We can have: - DHCP Server (Virtual Machine 1), - Firewall (Virtual Machine 2), - Squid proxy (Virtual Machine 3) - ...
0
votes
1answer
20 views

Using separated interface for virtualbox machine

I have a server connected to two network interfaces (via two different Internet services providers). The server runs Ubuntu OS. I want to use exactly one of the interfaces only for a virtualbox ...
1
vote
2answers
262 views

Arbitrary loopback ip addresses besides 127.0.0.1

I am developing a web app that has to produce different output based on ip. For testing and during development it would help a lot if I could have more loopback ip addresses besides 127.0.0.1. Is ...
1
vote
1answer
103 views

how to forward proxy requests using iptables

I've this schenario ----------------- ---------------- ---------- | SERVER A | ---(port:2128)> | PROXY | ---> | INTERNET | | (10.30.1.1) | ...
0
votes
1answer
105 views

Cannot close Port 25 after installing postfix

Before installing logwatch (which installs postfix) on Ubuntu 12.04, the port 25 is blocked by iptables/csf PORT STATE SERVICE 25/tcp filtered smtp After installing logwatch (which installs ...
2
votes
1answer
284 views

Ubuntu/KVM Bridge Interface IP Assignment

I have a Ubuntu 12.04 LTS machine running KVM/libvirt. It has two physical ethernet interfaces. I have dedicated eth0 as the primary interface and configured bridging on eth1 for my VMs. The KVM host ...
0
votes
1answer
128 views

Using isc-dhcp-server to allocate addresses from subnet different from server subnet

I'm trying to break my network into different subnets. Server is located into 192.168.15.0/24 subnet. I have the following declaration in my dhcp.conf: subnet 192.168.15.0 netmask 255.255.255.0 ...
-1
votes
2answers
147 views

Simplest way to monitor and log the internet traffic of a ubuntu server [closed]

I'd like to know if there is a simple program for ubuntu server (preferably 12.04), without too much configuration, which will allow me to check what processes are using internet bandwidth, how much ...
0
votes
0answers
130 views

PPTPD server on ubuntu 12.04.1 LTS not giving default gateway or forwarding windows client's packets

I recently bought a VPS, and wanted to set up a VPN with IP forwarding on it, both for resource sharing, and to DDoS protect a company’s windows VPS. I am not very experienced with networking on ...
0
votes
2answers
100 views

Should you use a private hostname or public hostname as server hostname?

Assume you have a web server and database server, the web server is publicly accessible, while the database is only used by the web server, their DNS is web.example.com web-internal.example.com ...
1
vote
1answer
88 views

no internet connection when in private network [closed]

I have an ubuntu server with a public IP, which I can reach with ssh from my local machine. However, when i put this server in a private network, I can no longer reach it with ssh from my local ...
1
vote
1answer
92 views

2 servers with 2 ip adresses cant ping each other

I rent 2 root servers from my provider that run Ubuntu 12.04.01 LTS. I ordered a second ip for each of them and configure them in /etc/network/interfaces as follows: iface eth0:1 inet static ...
4
votes
3answers
452 views

Can't stop DDOS [duplicate]

I need a little help dealing with ddos. I'm experiencing 1gb ddos attack on my server and I don't know how to stop it. (1gbs is the maximum speed of the server.) I've the following iptables rules: ...