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.
0
votes
2answers
22 views
Prevent internet access except for one server?
I want to see if the HTTP proxy support for an application is working correctly. In order to check this I have installed a Ubuntu VirtualBox on my Mac laptop and I want to configure the virtual ...
-3
votes
0answers
38 views
Accessing Linux File Server [closed]
I have been given a Linux server with a static IP address.
I don't know what the static IP address is.
I have plugged it into my Telstra Adsl modem
I can't see or connect to it.
how can I connect to ...
1
vote
0answers
33 views
How to configure 6 network cards in Debian 7
I am new in Debian and I have machine with 6 (six) network cards. It's gona be a cheap router, but Linux makes ethX devices only for 4 network cards (eth0...eth3):
root@dc-02:~# dmesg | grep eth
[ ...
1
vote
1answer
27 views
Enable multicast on dummy interface on startup
I have a dummy interface on a Centos 6.3 machine which I would like to use for multicast traffic. The problem is it does not come up with the MULTICAST option by default; I need to manually add it ...
0
votes
1answer
73 views
35 times increased latency between data send rate of 1 millisecond vs 100 microseconds. WHY?
Experiment
hping -S --data 100 -c 100 10.56.1.2 -i u100 round-trip min/avg/max = 0.5/14.0/15.8 ms
hping -S --data 100 -c 100 10.56.1.2 -i u1000 round-trip min/avg/max = 0.3/0.4/4.8 ms
Observation: ...
1
vote
0answers
24 views
Receive errors counter in /proc/pid/net/dev
Can anyone explain what gets reported in /proc/pid/net/dev in the receive "errs" column:
$ cat /proc/1372/net/dev
Inter-| Receive | Transmit
face ...
1
vote
0answers
18 views
How to use wvdial instead of network-manager in Debian
I would like to get rid of network-manager as it seems to be too magic for me.
However for the life of me I cannot figure out how to connect my UMTS-stick using wvdial (network-manager has no ...
1
vote
2answers
30 views
Linux: how can i configure dot1ad(double tag) on a interface?
I am on SUSE, and able to configure dot1q(single tag) for an interface. How can I configure double tagging on an interface?
Thanks.
0
votes
1answer
21 views
What process does 'own' socket in 'Time Wait' state?
Main question
I see following line in netstat. Does it means this socket doesn't belong to any process?
#>netstat -tpn|grep TIME_WAIT| head -1
tcp 0 0 ::ffff:127.0.0.1:5555 ...
2
votes
1answer
57 views
Linux: How to simulate several IP- and MAC-Addresses for networktesting in one linux box
I want to test a network with one linux-box which should get 100 different IP-Addresses, each with an own MAC which should be used as source MAC-address when communicating to other devices.
I've ...
1
vote
1answer
64 views
Can't set NIC speed to 10Gbps using ethtool
We're using IBM Blade Center HS-22 servers with Broadcom NetXtreme II 10Gbps NICs to a Nortel 10Gbps switch. With one of the chassis the NICs can establish a 10G rate with the command "ethtool eth2 ...
1
vote
1answer
51 views
How to forbid user to bind a socket on other than a certain address?
I want this user not to be allowed to bind ports (effectively creating world-accesible servers, though on ports >1024) on the Internet interface, but be allowed to do in the loopback interface on ...
0
votes
0answers
27 views
Adding second ENI to RHEL on EC2, takes network down
Background:
I have a RHEL instance on EC2 inside a VPC. This instance was created with the default ENI (eth0) on subnet 1. Now I have a situation where I am trying to add a second ENI (eth1) to this ...
0
votes
0answers
25 views
Monitoring bandwidth on multiple hosts with no control of a router
I'm looking for ways to monitor bandwidth usage for some Linux servers (and a couple of Mac/Windows servers, but if I can only do the Linux servers that will be OK).
I do not control the router that ...
2
votes
1answer
53 views
CentOS, ifdown on virtual interface removes IPv6 addresses on physical interface
In CentOS 6.4, when using 'ifdown' on a virtual interface, the IPv6 addresses configured on the physical interface are also removed. I expect only the virtual interface to be changed.
How can I ...
-2
votes
1answer
24 views
Connecting vmware on two computers [closed]
I have a switch and 2 computers, each one has vmware with a running centos 5.8 on.
what i am trying to do is ping centos2 from centos 1 through the switch(10\100).
please help.
2
votes
1answer
22 views
Unable to connect to Internet in OEL5 guest even though I can ping machine from host machine
I have Oracle Enterprise Linux 5 as Guest on VirtualBox running on Windows 7 host using Bridged Network.
I have being trying to configure a static IP on OEL5 VM Guest at work, as previously the VMs ...
-1
votes
0answers
15 views
Forwarding information about status of virtual interfaces
I need to send message with information about status of virtual interfaces on eth interface, every time when that status is changed using command ifconfig (for example interface virt1 goes down).
How ...
0
votes
1answer
62 views
Multiple ethernet interface on one ethernet card
First I must say that I am new in linux and maybe I will ask trivial question.
My job is to create 8 ethernet interface to be visible in kernel, but all of them should send and receive data through ...
0
votes
0answers
23 views
Route traffic through internal (VDE) bridge
I have two NICs configured, let's say eth0 with IP 10.0.0.1/24 and eth1 with IP 192.168.1.1/24.
IP forwarding is enabled, rp_filter is disabled.
I've created 2 tap interfaces and bridged them with:
...
1
vote
0answers
31 views
How can I set ntop not to shorten host names?
With most screens in ntop, there is a list of hosts. Unfortunately, in almost every one, the host name is shorted, for some reason. When the host names follow the company standard, this results in the ...
3
votes
2answers
93 views
Mysterious “fragmentation required” rejections from gateway VM
I've been troubleshooting a severe WAN speed issue. I fixed it, but for the benefit of others:
Via WireShark, logging, and simplifying the config I narrowed it down to some strange behaviour from a ...
0
votes
0answers
14 views
Broadcast across a VDE switch
I created a simple VDE Switch as per:
http://stackoverflow.com/questions/2082722/how-do-i-create-virtual-ethernet-devices-in-linux
To paraphrase that question, the setup is:
sudo vde_switch -tap ...
0
votes
0answers
39 views
Always get “SIOCADDRT: File exists” when restarting networking on ubuntu
I have a problem very similar to getting error "SIOCADDRT: File exists" when trying to restart network on ubuntu, but it is not a duplicate for reasons explained below. My ...
0
votes
3answers
58 views
How to safely capture or duplicate incoming requests to a web server
We have taken over a legacy web application that we cannot modify (the source code is broken and deployment fails) and we will eventually rewrite. Ideally we would migrate it one step at a time but ...
0
votes
0answers
52 views
Openvswitch configuration with Ubuntu VM
I have a Windows 7 PC as host.The network details of my Windows PC are as follows.
IP ADDRESS - 192.168.1.70
DEFAULT GATEWAY - 192.168.1.254
I have installed Virtual Box ...
1
vote
1answer
50 views
How do I receive traffic to the public IP of an additional ENI on EC2 Ubuntu?
I've added an additional network interface with elastic public and private ips. In ubuntu I can see the interface getting a local IP from DHCP, but I cannot ssh to the additional public IP.
I'm ...
0
votes
0answers
33 views
How do I figure what process is caching DNS
There seems to be some form of DNS caching on my machine as my networking scripts continue to give gaierror even after a broken connection has been reinstated. There is no nscd installed and dnsmasq ...
1
vote
1answer
41 views
how can I change the web server's identity into mine?
Can the web server execute a command in my Linux environment, and the Linux environment treat it as a request coming from me not from the server?
In other words, how can I change the web server's ...
1
vote
1answer
48 views
Is it insecure to use the following iptable rule for NAT?
I want to setup a VPN server for personal use, so I follow the blog article [1], and it work like a charm.
The only thing I am wondering is if the iptable's rule secure, e.g.
iptables -t nat -A ...
0
votes
2answers
845 views
CentOS 6.4 Missing Network Route on boot up after minimal install
I am testing a server configuration using CentOS 6.4. I do a minimal install and in the process of installing choose eth0 to be enabled at boot and enter a static IP address and gateway.
When I boot ...
0
votes
1answer
35 views
How can I find the cause of an unknown connection showing in iftop?
I have connections like this showing frequently in iftop:
12.15.127.75.host.nwnx.net => 121.61.153.172 480b 160b 40b
I have no idea ...
11
votes
1answer
483 views
arp-requests cannot be seen by specific nodes
I create an open ad-hoc wlan by using iwconfig (I have the same issue with wpa_supplicant as well). there are 4 nodes on the network as seen on the figure below. The nodes run ubuntu 12.04 and debian ...
0
votes
1answer
53 views
How to run Different congestion control algorithms in FEDORA 17?
I need to use different congestion control algorithms for tcp flow.
How can I continue using those flow congestion algorithms from Fedora 11 in Fedora 17?
-1
votes
2answers
61 views
determine IP for device [duplicate]
I am configuring an eth1 interface on in Red Hat, but I don't understand exactly what the IP address should be.
I'm given an IP of 10.237.128.0/25.
This means that the NETMASK would be ...
0
votes
1answer
83 views
Open source proxy server SSL interception and HTTP header insertion [closed]
I am new to proxies. Can anyone suggest an open source proxy server that supports SSL interception and HTTP header insertion.
1
vote
3answers
268 views
Bridging eth0 to wlan0
I'm trying to create the followig setup:
+----------+
| Wi-Fi |
+----------+
...
0
votes
2answers
54 views
I can't ping my server from certain IP
I have 2 internet connections from 2 different ISPs with static IPs, lets call them A and B. A connects to the server in several ways (ping, SSH, HTTP), while B cannot do anything (ping, SSH, HTTP).
...
2
votes
1answer
53 views
FreeBSD 2 network cards
We have server with 2 network cards with FreeBSD on it. 1 card used for internet (works fine) and another one for local network connection (to 192.168.227.0/24 net). When i try to ping gateway of ...
1
vote
3answers
127 views
How to “restart” particular network interface on RHEL?
In RHEL, instead of using service network restart command, how can i restart a particular network interface, lets say "eth1", with only one command.
"Only one command" because that is the only ...
0
votes
0answers
30 views
Converting uploaded MS Word docs (EC2 Linux server) [closed]
In my Linux server running on EC2 I need to be able to convert MS Word documents, uploaded by clients, to plain text. I've heard of Antiword, which seems like it could do the job easily, but what I'm ...
0
votes
1answer
60 views
Which Package has net_tstamp.h?
I attempted to compile the source code here: http://os1a.cs.columbia.edu/lxr/source/Documentation/networking/timestamping/timestamping.c?a=x86;v=2.6.32
However, I got a compiler error: error: ...
0
votes
1answer
103 views
How to scan New network card or any other devices in linux
I am trying to add a New Network card into Machine which has Linux installed. But my problem is, I cannot reboot the Linux host to detect the new network card, is there any workaround for this?
I ...
0
votes
1answer
61 views
Interface ip address discrepancy
This is very strange.
Output of ip route show:
default via 192.168.1.1 dev eth0 metric 100
192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.10
192.168.1.0/24 dev eth2 proto kernel scope ...
1
vote
1answer
73 views
Changing Linux Layer2 forwarding decision?
Are there tools to define in Linux something similar to Policy-based Routing, but on Layer2 level? Usual Linux bridge uses destination MAC to decide, which interface to send frame to. Can this ...
1
vote
2answers
126 views
Can I reassign eth1 and eth2 without rebooting the server
Say I have eth0 - my management interface,
then eth1 with mac1 and eth2 with mac 2- additional nics running.
How can I reassign eth1 with mac2 and eth2 with mac1 and bring them up without the reboot?
-4
votes
2answers
148 views
Hack Cisco Pix 501 to Run Linux [closed]
Can a Cisco Pix 501 be hacked to run Linux with a similar feature set?
Is this possible? Has it ever been done?
The pix seems like reliable solid-state hardware and it would be cool if I could run ...
0
votes
1answer
89 views
Add second IP block to one debian box (one nic) from different subnet than the first block
I have zero networking knowledge, so bare with me please.
I got the following:
xxx.xxx.199.208/29
xxx.xxx.221.64/27
The /29 IP block is available directly from the network drop
The /27 IP block is ...
1
vote
1answer
60 views
Why there are always 10% of loss when testing with mtr command?
For example, if I run this command against example.com, with mtr command, I always get 10% of loss, no matter how many time I run, why exactly is 10%?
mtr --report 192.0.43.10
HOST: localhost Loss% ...
-1
votes
2answers
110 views
iptables TCP handshake on Centos 6.0
Here's my iptables script:
#!/bin/sh
service iptables stop
iptables -F
iptables -P INPUT DROP
iptables -P OUTPUT ACCEPT
iptables -P FORWARD DROP
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -p ...
