Networking refers to the technologies and techniques that enable the interconnection of devices and applications allowing them to communicate electronically.

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1answer
56 views

OSPF port number

What does that mean "OSPF runs over IP as protocol number 89" as it bypassing transport layer using some socket?
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2answers
118 views

No internet access, but DHCP gives out IP?

I'm following EliTheComputerGuy's Windows Server 2012 tutorials to setup my Windows Server and office computers with Active Directory: https://www.youtube.com/watch?v=ZfsXh_LSkgE I want to setup ...
1
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0answers
11 views

rfc2307bis LDAP schema: ipNetmaskNumber lookup for an ipHost object

I'm using Openldap for IAM, and consider using it also as a configuration management backend. The rfc2307bis schema has an ipHost class, which allows for ipHostNumber attribute, but not for the ...
0
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1answer
26 views

Using a Gandi domain and a cloudfront default cert, how can I set up my CNAME records so that https works?

I have a website (www.foo.com), registered with Gandi. I have a static page on Amazon S3 (let's say s3.foo.us-west.com). I also have a Cloudfront distribution (foo.cloudfront.net). Originally, my ...
0
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1answer
18 views

Does adding more applications to a Citrix session increase network usage?

My understanding of the way Citrix works is that it basically sends screens from the server to the user at the other end. If the server has more applications running can it increase the amount of ...
0
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0answers
44 views

SMB2 disabled, but still functional?

The SMB2 protocol is: Enabled on SERVER1 (i.e, HKLM\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters\SMB2 DWORD is set to 1). Disabled on SERVER2 (the DWORD is set to 0). Enabled on ...
0
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0answers
33 views

Configuration SNAT iptables in ubuntu

I have 2 PC be created by VMWARE 1. PC1 (make iptables router): eth0 's IP: 192.168.1.4/24 (network connection is bridged) eth1 's IP: 192.168.2.2/24. (network connection is wmnet9) 2. PC2: ...
0
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1answer
17 views

How can I have one network card that allows traffic between two private networks?

This is a a question about a private network. I have two servers (Linux), srv1, srv2, each has one NIC. I have two switches (Cisco 3750), sw1, sw2 The servers are on two different subnets. srv1 is ...
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37 views

“The specified network name is no longer available” after little time inactivity

From a Windows 10 machine I use to connect to a remote machine. While some activity is performed between the two machines, everything is OK, but, if I stop all communications among them for a while (e....
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3answers
2k views

Resolve linux hostname in windows

I have a simple home network with Windows 7 machines and Linux machines (Fedora 12 and 13). I'd like to be able to resolve the Linux machine names from the windows machine. For example: -- Windows 7 ...
0
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1answer
40 views

How can I ping devices on Class B network when remote VPN issues Class A network address?

I've been playing with the Sophos UTM Home Edition, and I've noted that SSL VPN connections are issued Class A addresses. Given that the current internal network leases Class B addresses, why can I ...
2
votes
1answer
16k views

LOM vs. NIC for iDRAC with Dell PowerEdge R720xd

I'm trying to get going with iDRAC 7 Express (no Enterprise license so we can't use the dedicated port). In the setup menu for iDRAC, it asks to choose which network interface to use for iDRAC. ...
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2answers
43 views

DNS Look up does not show if domain starts with www

I am a little confused about DNS look up. If I add 'www' to the domain while looking up I see no records. But if I remove 'www' from the domain and then query, I see the DNS records. DNS Propagation ...
3
votes
2answers
6k views

Traceroute, ICMP, UDP and TCP

When does traceroute use TCP? Or does it just use UDP, also why does Traceroute use UDP on MacX and ICMP on windows? I thought ICMP just contains a message saying what caused the error of a packet and ...
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3answers
38 views

Expand wlan with a wlan router or access point [closed]

My wish is to expand the WLAN network, because of aborted connections. That means, the "central" router gives the internet connection in the LAN and the other router/access point uses the LAN ...
1
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0answers
36 views

network device enrollment service greyed out

I've recently installed AD Certification Authority on one of our DCs. It acts as a subordinate enterprise CA, the Root CA is a standalone offline root CA and there is no connection between those two ...
6
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1answer
13k views

Will increasing net.core.somaxconn make a difference?

I got into an argument on the net.core.somaxconn parameter: I was told that it will not make any difference if we change the default 128. I believed this might be enough proof: "If the backlog ...
1
vote
1answer
46 views

What should i use instead of eth0:1 if it is deprecated

usually i create /etc/sysconfig/network-scripts/ifcfg-eth0:1 and /etc/sysconfig/network-scripts/ifcfg-eth0:2 but i seen in internet that it is deprecated using eth0 :1 so what can i use to the VPS ...
0
votes
1answer
34 views

Traffic from within Docker containers routing incorrectly— traffic from Docker host routes correctly

I'm seeing a weird problem where traffic originating from within a Docker container located on a VM in the Google Cloud in europe-west1 and destined for a UK company based in Amazon's Cloudfront is ...
0
votes
1answer
33 views

debian networking does not restart properly

I have a Debian 8 machine, where I've configured two VLAN interfaces in /etc/network/interfaces. Now I've deconfigured it (deleted information from interfaces file), restarted networking, and now it ...
2
votes
1answer
133 views

Routed bridge networking for KVM guests along with eth1 alias interfaces for shared hosting with dedicated IPs for each virtualhost

First question here on serverfault, so kind of a newbie, all feedback is welcome. I have a dedicated server running Debian GNU/Linux 8.4 (jessie) with one public IP and multiple additional public IPs ...
0
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0answers
37 views

virtualbox networking - difference between 10.0.2.2 and 10.0.2.15

I setting up a vm-based appliance on VirtualBox (using Chef) and, while I have figured out my networking out by trial and error, I'd like to understand better what's going on. Basically, I have 3 ...
1
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0answers
35 views

cisco asa public server nat issue

I have been tasked with some ASA configuration coming in a few weeks, and to test out some configuration options I have setup a web server on my local network which I would like to be able to access ...
5
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6answers
24k views

Ubuntu Server 12.04 can access LAN but not internet

Using Ubuntu Server (12.04) via command line, I can access the LAN (e.g. ping local machines) but not the internet (e.g. "ping google.com" or "sudo apt-get update"). How should I troubleshoot this? I'...
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1answer
68 views

“Ipcalc -n ipv6_addr” command is giving error

I am trying to calculate network address of Ip address by using Ipcalc command. when i am using ipcalc -n ipv4 address,then it is running fine and give the network address for the IPv4. But when i ...
1
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1answer
53 views

CentOS 7 statically configured network adapter keeps getting DHCP address

This is driving me nuts. I have a CentOS 7 system. It is acting as DHCP for the network it is attached to, is running Cobbler and PXE, but it is not the gateway. It is the primary file server for ...
0
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3answers
6k views

Can Wireshark capture an entire Ethernet frame including preamble, CRC and Interframe spacing?

I am examining an Ethernet frame in Wireshark. According to the "Ethernet frame" Wikipedia article and accompanying diagrams, "A frame starts with a 7-octet preamble and 1-octet start frame delimiter (...
2
votes
1answer
68 views

Proving packets per second bottleneck?

I have a '100Mb' network connection that's currently consistently transmitting at about 20K packets/sec, irrespective of packet size in the range of 300-600 bytes. This yields an observed bandwidth ...
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0answers
16 views

Windows Server 2012 Printer Management

I want to add a shared printer connected to a host IP (192.168.0.10,windows 7) , to a server (192.168.0.200,windows server 2012). When adding a printer using the Printer Management just the IP ...
1
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0answers
51 views

How to connect to a service on a local network machine whch which only listens to localhost?

I have a service which only listens to localhost on port 7400. There is a service running on a windows and an ubuntu machine on a private network. How can another computer on the same network ...
2
votes
1answer
61 views

Simulate massive network traffic [closed]

We want to stress test our pfsense box with a massive amount of connections and traffic. Right now we are using iperf, but reaching a number of more than ~300 parallel connections the test clients ...
3
votes
3answers
26k views

CentOS 6.5 not bringing up network interface automatically after reboot [ifup eth0]

I am having this issue with many of my CentOS servers where after a reboot the network interface fails to come up automatically. This is a big problem for me since I need to drive to the datacenter ...
0
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3answers
93 views

IP forwarding on Linux

I have three machines Source Machine Destination Machine - IP 10.20.30.40 Intermediate Machine - Host server1.test.com Source machine has SSH access to Intermediate machine and Intermediate machine ...
0
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1answer
48 views

Ip addressing for serial routing

I have the following packet tracer diagram: I have range of ip address : 10.0.0.0 - 10.0.255.255 I need to assign ip addresses from this range to the routers' serial interfaces as well as subnet ...
0
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0answers
15 views

Network issue with VMs mixing dedicated public IP and port forwarding

I already have a virtual machine with its own public ip address and I would like to set up a new VM using port forwarding from the host. I have two public addresses: X.X.X.146 for the host Y.Y.Y.99 ...
0
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1answer
50 views

How calculate printer average-toner-coverage used per page using SNMP

I want to know the rage toner used per page, for example: for one page print was used x toner for other page print was uses 2X toner I suppose are some SNMP mibs/oids to do this; some idea ?
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votes
1answer
40 views

One way network bridge [closed]

I have two networks, with a single machine sitting on both (two NICs) shown below. That machine is Linux. I was hoping to set up a bridge of some sort so that work stations on the 192.168.1.x ...
0
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0answers
12 views

Configuration snort IDS

I have installed snort on my windows 7 machine. But during configuration of snort, it gives me the following error. ERROR: c:\Snort\etc\c:\Snort\rules\app-detect.rules(0> Unable to open rules "c:\...
0
votes
1answer
37 views

How to share two ISP in two router configuration?

I have two router configured in lab. To configure network redundancy, I want to configure one ISP on each router. So if network on one router goes down, we will have the network connectivity from ...
0
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0answers
18 views

DNS forwarder to ingest client-subnet as EDNS option in outgoing query

I am looking for DNS forwarder able to apply following logic to forwarded queries: - If EDNS client-subnet option present in query from client, preserve it - Otherwise, calculate client-subnet from ...
0
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0answers
32 views

I'm having random nfs slow downs on my nfsv4 gigabit network which cause videos to slow down then speed up

I've noticed this issue happen in two different video players so I'm pretty sure it's a network problem. I'm running Ubuntu with the kernel 4.2.0-35-generic. Here is the result of my nfsstat -4 -s -...
5
votes
2answers
8k views

Which openvpn cipher should I use?

From both a performance and security standpoint, which cipher should I use with openvpn? According to http://openvpn.net/index.php/open-source/documentation/howto.html#security , the default is ...
0
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0answers
41 views

Issue with nfsen in fetching sflow data from Linux host

I have two VMs. The first VM is at AWS EC2 instance (red hat). I am using this system as sflow agent. I have installed hsflowd in this machine. My hsflowd.conf file looks like following: DNSSD = ...
0
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2answers
209 views

Why is fragmentation done on layer 3 (Network layer)? [closed]

Why is fragmentation done on network layer and why not on other layers ? Fragmentation means splitting the packet into to small pieces and sent from source to destination. The maximum MTU size is ...
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0answers
56 views

Drop fragmented packets in nftables

Using iptables is it possible to block fragmented packets with this rule: iptables -A INPUT -f -j DROP But there isn't a equivalent in nftables. There is any way to do it?
2
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1answer
182 views

nftables alternative for iptables -F

Simply, is there any quick alternative of iptables -F command (that just "deletes everything") for nftables? Such thing wouldn't have much theoretical purposes, but it's usually a lifesaver for ...
0
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0answers
17 views

Network connections on aws ec2 in poll_s

Our long running mail server on aws ec2 suddenly faced network related bottlenecks today. The pop service was running at its limit, still end users complained of connection errors and duplicate mail. ...
1
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1answer
49 views

Disable eth0 on boot, but allow to turn back on

We are setting up an offline/offsite backup server. The purpose is to have it offline and uncontactable from anything. Then, once the cron starts the backup process it will enable the network, backup ...
0
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0answers
41 views

Forward port 80 to 8080 for a specific IP on the network

I have a specific PC on my network running a web service on port 8080. I also have a different machine which acts as a gateway/router, which I configure using iptables rules. What I want to do is ...
1
vote
1answer
49 views

fast ping response, latency on traceroute

I have a very strange problem. In short pings to my wireless AP are low (around 1ms), however, once I do a traceroute, the latency to the AP (1st hop) suddenly jumps to ~1000ms. Any ideas what may be ...