7
votes
7answers
819 views

Best choice of private addresses for a “device area network”

I'm building an appliance consisting of several subdevices connected by ethernet inside the appliance. The appliance will connect to the customer network. The customer network can be using private ...
1
vote
1answer
64 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 ...
4
votes
1answer
580 views

Docker will only bind forwarded ports to IPv6 interfaces

Is there a way I can tell docker to only bind forwarded ports to IPv4 interfaces? I have a machine running on Digital Ocean with IPv6 disabled: # echo '1' > ...
0
votes
2answers
108 views

Why is there a total length field in the IPv4 header? [closed]

Headers of IPv4 datagrams feature a field called total length coded on 16 bits. As there already is information about the header length of the datagram, having the total length seems redundant: it can ...
0
votes
1answer
120 views

IPv6 and IPv4 mapped address

I've a box with 1 private IPv4 (192.168.0.X) and some IPv6 (let's call one Y::Z). I have an application listening on 192.168.0.X on port 1234 and an application that want to connect to that service ...
-1
votes
2answers
83 views

How many possible IP ways to interpret 1 IPv4 address (including masks)? [closed]

Considering subnet masks, how many ways can 1 IPv4 address be interpreted?
2
votes
2answers
326 views

Server sending out packets bigger then MTU

I have a server that I am transferring data off of. We were having some problems that were traced back to the fact that the server is sending out jumbo size frames despite the fact that ifconfig is ...
1
vote
0answers
153 views

Netlink error while using IP queue

I seem to have an issue with IP queue. I have a linux machine that I am using to run some experiments. The linux machine is configured to be a router, having two NICs, connecting two other computers, ...
0
votes
1answer
356 views

Reach pc in the same network but a different subnet

PC 1 in subnet - 192.168.1.x PC 2 in subnet - 192.168.2.x Is it possible to access one pc from the other by its IP address without special router config? related: How to reach a device on a ...
3
votes
2answers
418 views

Protocol (or service publish/discovery) to detect devices in network

we connect some embedded devices in a network. What i am looking for now, is a way to find the devices IP and identify them. We work with Windows PC´s and i am about to write a C# tool that should do ...
0
votes
2answers
122 views

IP address in production server suddenly conked-out

Here's the situation: my company runs a website, but we don't have anybody in-house qualified to be a sysadmin, so when something goes awry, we're very much at the mercy of our hosting provider's ...
1
vote
2answers
198 views

Static Routes and the Routing Table

This is very much a learning question if someone would be happy to explain a couple of concepts. My question is - the default routing table that exists in, in my case, a default Windows 7 install, ...
1
vote
2answers
7k views

Domain connection shows as “unauthenticated”

I have seen various different questions for this problem floating around but either the circumstances arent the same or the solution doesnt work so thought i would post it to see if anybody has any ...
142
votes
13answers
22k views

Why couldn't MAC addresses be used instead of IPv4|6 for networking? [closed]

I am reading up on TCP/IP and other related protocols and technologies. MAC addresses are described as being (reasonably :) unique, and as having a large possibility space (several hundred trillions), ...
0
votes
2answers
163 views

Iptables: Drop all incoming IP4 traffic on a port

I want to drop ALL the ipv4 traffic on a certain port and only allow ipv6 traffic with iptables. Is it possible? is so, how?
2
votes
1answer
41 views

Strategies physical server running multiple guests but having a single external IPv4

My hoster is - understandably - cutting down on IPv4 addresses offered with new servers so that the next time I re-locate my stuff to a new server I'll a huge number of IPv6 addresses, but only a ...
2
votes
1answer
1k views

Disable IPv4: What exactly does 'ifconfig eth0 0' do?

I'm experimenting with Linux and networks. What I'm trying to do is disable IPv4 for remote connections. It shouldn't be that complicated but I didn't find much about this topic. However, there is one ...
0
votes
3answers
917 views

Pros and cons IPV6 vs stretched vlans

I'm having a hard time finding information about whether implementing ipv6 or using a stretched vlan is a better option for geographically dispersed sites is better. Does anyone know: Problems with ...
0
votes
3answers
137 views

What transport protocols can be routed properly over the Internet, other than TCP and UDP?

I recently noticed that my ISP doesn't like routing native SCTP traffic over the Internet, unless it's tunnelled through UDP. A bit of a pain, but I solved the issue by using tunelling. This issue ...
0
votes
1answer
109 views

Obtaining and routing small IPv4 space?

I had an idea for designing a network setup in order to acquire high availability connections to my (small) network, but I seem to be running into a few problems trying to find out the particulars. ...
1
vote
3answers
1k views

Are same IP address with different submask unique? [duplicate]

Possible Duplicate: How does Subnetting Work? In a same block of IPv4 addresses, can there be same IPs with different submasks? For example, can I have this: 180.70.65.140/26 ...
0
votes
2answers
410 views

Traceroute doesn't reach gateway

i have problem with my opensuse 11.3 network. So, i've assigned ip 192.168.137.2 to it, and another computer (win7) with ip 192.168.137.1 On the opensuse, the gateway is the 192.168.137.1. and the ...
7
votes
4answers
644 views

CIDR Ranges for Everything except RFC1918

I'm looking for a list of CIDR blocks for "The Internet", i.e. everything from 0.0.0.0 to 223.255.255.255, excluding RFC1918 address space of 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 (yes, I know ...
7
votes
4answers
2k views

Why can't I ping an address on the loopback device under FreeBSD?

From Wikipedia: The most commonly used IP address on the loopback device is 127.0.0.1 for IPv4, although any address in the range 127.0.0.0 to 127.255.255.255 is mapped to it. This is not ...
1
vote
3answers
2k views

Am I supposed to assign the broadcast IP somewhere?

This is a very basic question from a newbie point of view. I have a dedicated server at Hetzner running Windows 2008 R2. I bought a subnet of IP addresses to use in this server. They provided me a ...
12
votes
4answers
563 views

How to prepare (or not) small company to IPv6

There's an ongoing "panic" all over the news for some time now about IPv4 running out and IPv6 being the savior. All the big companies are preparing and showing how it should be done (last actions ...
5
votes
4answers
2k views

Networking Question - What is a VALID Subnet Address? [duplicate]

Possible Duplicate: How does IPv4 Subnetting Work? I am currently revising Networking for the Cisco CCNA1. One of the questions that I am struggling to answer is the following: Which of ...
5
votes
3answers
2k views

How to completely disable IPv4 stack from Linux?

How can I disable IPv4 stack from Linux ? I want to do that dynamically, ie. sometimes I want it enabled and sometimes I want only IPv6 stack. Is there any portable way to do that ? If you know how to ...
0
votes
3answers
14k views

Win7: How to solve: Unidentified network/No Internet connection problem?

It's been a few days now that I have gotten problems and problems with my network connection, though my other computer works fine! The problematic computer is operating with (PC2) Windows 7 ...
13
votes
5answers
1k views

IPv6: How to start? (ISP perspective)

In our company we have a range of /21 (2048) IPv4 public addresses. We have a bunch of Cisco routers and servers. How to get started with IPv6? What can we do to provide internet to our clients with ...
0
votes
1answer
41 views

enabling ipv4 forwarding locked up machine. ideas?

Hey. I'm running cent 5.5 64-bit, 1 nic, eth0. I enabled ipv4 forwarding via: echo '1' > /proc/sys/net/ipv4/ip_forward and the machine locks up. cant switch ttys cant ssh into it. Had to hard ...
-3
votes
3answers
419 views

IPv6 is comming [closed]

Very soon, all of us will face one of the greatest changes in the global network in last 30 years: moving to the IPv6. So many system administrators will have to decide, how to handle this problem: ...
5
votes
5answers
2k views

Why is ipv6 128bit and not 64bit?

Computer processors moved from 32bit to 64bit. Why have IPs moved from 32bit to 128bit (skipping 64bit) ? EDIT: I did not intend to make a direct comparison. Just curious why IPs skipped 64bit.
0
votes
1answer
369 views

How to assign two IP addresses (one DHCP, one static) to a NIC in OpenSolaris?

This should be mind-numbingly simple and basic, and yet I couldn't find how to do it, either in "man ifconfig", in the OpenSolaris docs site, or Googling in desperation. I'm using OpenSolaris 2009.06. ...
4
votes
2answers
2k views

how does ping resolve to ipv4 on one machine, but ipv6 on another?

Background I have two environments, TEST and STAGE. I use Microsoft Distributed Transaction Coordinator (MS DTC) with two linked 2008 SQL servers. A SQL job runs every couple of minutes and ...