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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19
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1answer
26k views

How to reduce number of sockets in TIME_WAIT?

Ubuntu Server 10.04.1 x86 I've got a machine with a FCGI HTTP service behind nginx, that serves a lot of small HTTP requests to a lot of different clients. (About 230 requests per second in the peak ...
0
votes
1answer
23 views

Clients losing stateless ipv6 addresses

I'm having problems with Linux VM's at a certain VPS hoster. Periodically the hosts lose their ipv6 address. They go to 'deprecated' and then disappear completely. On the client side I have checked ...
1
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1answer
1k 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) ...
0
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0answers
11 views

zeroshell unsupported onboard Intel Ethernet I217-V and I210

I recently installed zeroshell 3.0.0 on a machine with a supermicro motherboard that has 2 onboard ethernet cards. It seems that this version of ZS does not support both of ethernet. I've read from ...
1
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1answer
10 views

Can I use --duplicate-cn option for a specific VPN account instead of using at server level?

If I use --duplicate-cn I am seeing it taking effect over all the accounts of my server. I want to make it per client basis, so that I can give this option only to select accounts. Is it possible?
0
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0answers
8 views

How to config Squid SSL bump to let Paloalto PA series firewall recognize App-ID

A Paloalto firewall(PA-2050,POS 4.1x) was capable of recognizing the websites which users are visiting(thru http/https) then flag them with a App-ID and apply application control on the traffic, for ...
0
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0answers
5 views

TOS reflect on pppoe tunnel in Linux?

How to perform TOS reflect in Linux? In this case, on a pppoe tunnel through eth0, reflect TOS from each pppoe packet onto the actual ethernet packet going thru eth0. On some nicer routers it's a ...
0
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0answers
7 views

VPN Connection pooling?

I'm having a problem on PFSense https://forum.pfsense.org/index.php?topic=23914.0 where I can only connect one client with a PPTP VPN to a VPN Server outside out network. PFsense is our firewall and ...
1
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0answers
9 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 ...
-1
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5answers
69 views

How do i down the server on the remote location for an hour

This is the doubt i have in my mind we can reboot the remote server using reboot command but how can we down the server for an hour or a specific time. In our case we login to the server through putty ...
1
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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 ...
0
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0answers
22 views

Open vSwitch double VLAN tagging is ignored

I'm trying to add a flow to a KVM machine using Open vSwitch 1.10.2 for it's networking, which double tag all traffic comming from one of the virtual machine's ports. I'm using the following command ...
0
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0answers
21 views

Ubuntu server - NIC suddenly loses connectivity

I'm scratching my head. I recently configured a server with two identical Intel NICs inside a DMZ. This morning at around 8:05, I successfully SSH'd in through the internal interface (via my LAN-based ...
1
vote
1answer
260 views

Adding a whole IPv6 /64 block to an network interface on debian

I tried adding a whole IPv6 (/64) block to an interface using ip route add local 2001:41d0:2:ad64::/64 dev lo like described here on my Debian server, but I seem to be missing something. If I ping ...
1
vote
1answer
23 views

ssh connection freeze after password phase

I'm trying to connect to a server (Oracle Linux 6.3) and after I insert the password the session just freeze. I checked the audit log and I've authenticated successfully, after I restarted the ...
-1
votes
1answer
49 views

Designing a secure network layout

Over the last few years I've accumulated a lot of hardware that all currently exists on a flat network. There are a number of devices: my desktop, laptop, and computers of the rest of the people I ...
0
votes
2answers
25 views

Can I limit my autoSSH Tunneling Speed with trickle and ssh config file option?

When I use only ~$ autossh site1 it work perfectly, but whit trickle the pameter site1 is considered as DNS Name instead of conf block. User@VM:~$ sudo trickle -d 10 -u 10 -- autossh site1 [sudo] ...
0
votes
1answer
7 views

autostart ppp connection when vlan comes up

I want to start a ppp connection on my router on startup, but i need to have a vlan activated before. The problem is that if i ifup the vlan in the ppp interface, the vlan is not up when pppoe tries ...
1
vote
1answer
56 views

Posftix mails not arriving to external recipients (closed port)

I have an Ubuntu Server (192.168.1.2) behind a router (192.168.1.1 with static public IP a.b.c.d and domain example.com). Apache works fine and is accessible from the outside under example.com. On ...
0
votes
1answer
900 views

Trixbox CentOS Default GW Problem (Multi-homed server)

I'm having an issue with a CentOS trixbox server which is dual-homed (one private facing NIC [eth1], one internet-facing NIC [eth0]). I can't seem to get the default gateway to set properly to our ...
0
votes
1answer
640 views

SASL - Plaintext password not accepted - Encrypted works

I have a very strange issue! SASL does not work properly, as it does not accept plain-text passwords (like Outlook sends them) Oct 2 10:35:09 srf cyrus/imap[4119]: accepted connection Oct 2 ...
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4answers
214 views

Is there anyway to tell what user will receive data from inbound packet?

In linux, considering this use case: 1. User initiates http request for webpage to remote server 2. Remote server answers request and sends packets Is there any reference to the user who started ...
0
votes
1answer
42 views

storage traffic not going through Bonded interface

hi few days back i have asked a question here choosing network interface based on network purpose on my Centos server there are 4 NICs i bonded first two NICs and created bond0 with an MTU of 8600 ...
0
votes
1answer
928 views

Diagnosing packet loss / high latency in Ubuntu

We have a Linux box (Ubuntu 12.04) running Nginx (1.5.2), which acts as a reverse proxy/load balancer to some Tornado and Apache hosts. The upstream servers are physically and logically close (same ...
-2
votes
1answer
30 views

PPTP and windows 7 809 error [closed]

I want to connect from home to my router(linux mashine) at work. i have installed pptpd. i have added following fw rules: iptables -I INPUT -p tcp --dport -j ACCEPT iptables -I INPUT -p gre -j ...
0
votes
1answer
17 views

squid3 with tcp_outgoing_address could not connect to anywhere

I have one server with 3 interfaces (3 physical lan card), which are connected to 3 different routers. Each router has a different subnet, i.e. the 3 interfaces of server belong to 3 different ...
1
vote
2answers
2k views

How virbr0-nic is created?

How can I create Virtual Network Interface like virbr0-nic? I am trying to find a way to create NIC like virbr0-nic but everything which I can find in internet is how to create interface attached to ...
0
votes
0answers
40 views

Linux routing: How to allow a device inside private network to connect a public IP over an unknown network?

Consider following network topology: ---------- ---- (my network) ---- | Device 1 | (.101) | 192.168.191.0/24 | ---------- | | ...
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 ...
1
vote
1answer
94 views

Kali SYN Flood (Metasploit), not denying service

I have a server with apache2 installed. I tried to do a dos attack on the server by using kali linux syn flood attack, but i am still able to access the website on the server. msf auxiliary(synflood) ...
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votes
2answers
67 views

Is it possible to do Linux network namespaces (netns) on MacOS?

Context - I'm trying to get a docker cluster running on MacOSX. Part of the install process for getting docker running is to install pipework. Pipework relies on /var/run/netns My question is: Is ...
0
votes
1answer
696 views

Check packet vlan tag using Tap virtual interface

I am trying to learn how to implement virtual interfaces using the Tap driver. So far my understanding is that using the tap driver I can create a virtual interface and then have a userspace program ...
2
votes
2answers
393 views

Linux does not get IPv6 default gateway from Cisco ASA5510 on autoconf

My ASA 5510 has the following configuration for an interface. My Ubuntu box (2.6.35) connected to this network will correctly autoconf an IPv6 address, but it will not set a default route. interface ...
1
vote
1answer
695 views

how to make bridge networking with KVM work in Fedora19

I'm attempting to get several virtual machines setup on a Fedora-19 host system, with the traditional bridge network devices (br0, br1, etc). I've done this many times before with older versions of ...
1
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0answers
13 views

Long access time for static web page on virtual machine [migrated]

My setup Windows 7 on workstation that I use at work (with domain) and home (no domain) Virtual machine (VMWare) that runs Arch Linux (I will call it just "Linux") with network interface in bridged ...
1
vote
2answers
82 views

All traffic is passed through OpenVPN although not requested

I have a bash script on a Ubuntu box which searches for the fastest openvpn server, connects, and binds one program to the tun0 interface. Unfortunately, all traffic is being passed through the VPN. ...
1
vote
2answers
2k views

scp to remote servers stalls, unable to isolate cause

When I copy a large file (100+mb) to a remote server using scp it slows down from 2.7 mb/s to 100 kb/s and downward and then stalls. The problem is that I can't seem to isolate the problem. I've ...
0
votes
2answers
94 views

Force an LXC container to use its own IP address

Sorry if this question has already been asked. I could not find it, I have this setup : +---------------------------------------------------------------------------------------------+ |HOST ...
4
votes
2answers
1k views

Is it possible to enable port isolation on Linux bridges?

On most managed switches you can enable Layer 2 Port Isolation. The implementation and terminology is different from vendor to vendor but generally speaking you keep one or more ports in the default ...
1
vote
0answers
21 views

Losing connection to server from several computers

I have a PostgreSQL server running Oracle Linux. In my network I have several workstations each running different OS (Fedora, Ubuntu, Windows). Every once in a while I lose connection from the several ...
1
vote
1answer
57 views

How to exclude LAN traffic from IPSEC policy

I am trying to replace a Firewall/VPN appliance (Snapgear SG300) with another (Mikrotik RB951G-2HnD). My current router works, but, for the new mikrotik router, when I add the phase 2 tunnel, I can ...
1
vote
1answer
135 views

How to stabilish a VPN connection, only on port 8080

Infrastructure: Here's what I want, be able to connect to the website 10.10.100.32:8080 from my LAN on 'Router 1', and all the traffic outside the port 8080 should go to the default gateway 'Router ...
1
vote
1answer
23 views

How to set up custom multicast address

What would it take to setup a custom made multicast ip address in the network? Machines are linux. Let's say I want to have a multicast address with only some machines from the network as group ...
0
votes
0answers
70 views

php-fpm process in D state ,cause nfs wait rpc_wait_bit_killable

my wordpress site which is in clustered environment using NFS,nginx,php-fpm,mysql the infrastructure is hosted on amazon ec2.Under high load/traffic the php5-fpm process goes in D ...
-2
votes
1answer
42 views

Trace route to specific page on a website [closed]

If I can access a site (ie: serverfault.com) through my proxy/firewall, it means that it will allow all it's subdirectories (serverfault.com//)? I can access the website site.com/ but it returns me ...
2
votes
1answer
45 views

Rate limiting udp packets destined to a linux machine

Is there any way to ratelimit udp packets destined to my linux machine? I am sensing some udp packet drops destined to my machine. Was there any default udp rate limiting conf in linux? I have seen ...
3
votes
2answers
146 views

Linux adds the wrong default route

For some reason my Centos 5.9 Linux 2.6.18 x86_64 wants me to have two default routes. Whenever I reboot the server, my routing table looks like this: [root@server1 ~]# route -n Kernel IP routing ...
1
vote
3answers
182 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 ...
0
votes
1answer
66 views

Network configuration for linux server

I had some troubles with a Linux server after being restarted. I can log to the machine but I cannot remotely access this machine via ssh client: ssh -v -v -v root@IP gives me connect to host IP port ...
0
votes
1answer
52 views

Can't reach multi-homed Ubuntu from different subnet

I have a multi-homed Ubuntu 12.04 server. I have two network interfaces connected to two different IP ranges. 2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen ...