Refers to the 4th revision of the Internet Protocol, where addresses are usually displayed in the form of dotted decimals between 0-255. Ex: 169.254.0.1

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2
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1answer
420 views

Does Linux support IPv4 mapped IPv6 addresses?

I work in a mixed IPv4 / IPv6 environment. I read that IPv4 addresses can be mapped into the IPv6 space with this syntax ::ffff:1.2.3.4 (1.2.3.4 is the IPv4 address) Does Linux support this ...
0
votes
2answers
103 views

Why does ipv6 not specify a protocol version?

I am relatively new to dealing with network packets, but as I look into the ipv6 header formats, I do not see a place where the ipv6 headers define what protocol is used in the data section -- but the ...
0
votes
1answer
78 views

MAC Address & IPv6

While MAC addresses are 48 bits, that is a lot more than the 32 bit IPv4 adresses (even counting the reserved addresses 255, 127, Class D Multicast etc ), will we not eventually run out of them? ...
0
votes
2answers
151 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 ...
2
votes
1answer
546 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 ...
-1
votes
1answer
66 views

IP testing tool similar to wireshark website [closed]

I am looking to implement a tool similar to the one linked below on my personal server/website what are the steps I would need to get started? http://www.wireshark.org/tools/v46status.html I ...
0
votes
1answer
228 views

Getting DNS replies for non-existing hostnames (DNSMasq)

I noticed some 'weird' DNSMasq behavior when I set up my LAN for dual stack IPv4 & IPv6 networking. It seems that my DNS server (DNSMasq) which acts as a forwarder and also has all the host names ...
1
vote
3answers
100 views

RHEL (say 5.6, kernel 2.6.18-238) with dual IP address (IPv4v6)

So I have a SERVER that that utilizes RHEL's (assume 5.6) underlying kernel for setting up TCP connections and other networking aspects. My deployment need requires that the SERVER have dual IP ...
2
votes
1answer
484 views

FreeBSD Nic Setup - Dual NICs with lagg

I have a server running FreeBSD 9.0. It has two NICs using the igb network drivers. I was given a range of IPs, for example's sake I'm just going to make up some IP addresses, so let's say ...
2
votes
1answer
2k views

Open Windows Firewall to all connections from specific IP Address

Is it possible to "whitelist" an IP Address in the Windows Firewall and allow all connections from that specific address?
0
votes
3answers
195 views

textbook CIDR subnet problems, the real world, and Cisco ip route [duplicate]

Assuming CIDR and classless addressing, the CCNA books I'm reading say Pearson 640-822 official cert guide 2012, pgs 403-404: According to their method S = P - N (subnet, prefix, host bits ...
2
votes
3answers
4k views

Should I create a multicast route on RHEL/CentOS for a blind sender?

A CentOS 5 system does not appear to come out-of-the-box with a route for multicast traffic. What it does appear to do is use a default route, if configured. In other words, a routing table like ...
0
votes
1answer
167 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 ...
0
votes
2answers
154 views

ngnix startup isse ipv4 & ipv6

I'm trying to get my first nginx server setup, and am having trouble setting up ipv4 and ipv6. I have this in the top of my config file (it's the only server block in the config file): server { ...
-1
votes
1answer
134 views

Apache2: Dual Stack mode IPV6 / IPV4 for existing IPV4 hostings [closed]

I'm planning to run my hostings in the IPV4/IPV6 dual stack mode for a lot of hostings / IPs. Short Apache example: ports.conf Listen 199.192.201.82:80 NameVirtualHost 199.192.201.82:80 Listen ...
-1
votes
2answers
91 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?
0
votes
1answer
383 views

Getting ipv6 only on ubuntu server with vmware bridge connection

I have ubuntu server 12.10 on vmware. When I have NAT network configuration I get ipv4 address (checking ifconfig eth0). With bridged connection I get only ipv6 connection, but I need an ipv4 ...
0
votes
1answer
342 views

How can I get unique IPv4 and IPv6 visitor counts on nginx access.log in shell?

How do I get some stats on unique IPv4 and IPv6 visitors by looking at a nginx access.log with UNIX CLI? I use the standard combined pre-defined format for access_log.
0
votes
1answer
274 views

Inject packet to a different NFQUEUE

I have an NFQUEUE, for IPv6 packets hooked to PREROUTING chain of mangle table in ip6tables. Once I receive a packet in user application, I modified the header. Infact, modified the header from IPv6 ...
0
votes
1answer
307 views

SMTP - Remove IPv6?

We're doing a "try-out" of SmarterTools SmarterTrack (help desk) software. We can't get it to send email. We showed someone at SmarterTools our log - SmarterTrack keeps its own SMTP log - and they ...
0
votes
1answer
280 views

Can I configure routing to a host with public ip address via a private network?

This question has alread been posted on stackoverflow (http://stackoverflow.com/q/14904325/2012441) but since I recognized that it might be offtopic there, I'll repeat it here: I'll explain the ...
1
vote
2answers
81 views

Forward traffic from IP6 to IP4

On my debian6 server is a process that only listen on IPv6 but I also need to listen on IPv4. It seems the program is IPv6 only. Is there a way to route the traffic fom IPv6 to IPv4 on the same host ? ...
-3
votes
2answers
2k views

CentOS 6.3 - Add IP's To Eth0?

How would I go about adding 3 IP's to my eth0. When I tried the following, the whole network crashed. ifconfig eth0 192.95.22.105 netmask 255.255.255.0 gateway 198.27.64.254 How would I go about ...
0
votes
1answer
231 views

Assigning two IPs to one NIC in CentOS

I have been following this method described here: http://linuxwave.blogspot.com/2010/01/setting-virtual-ip-in-centos.html To assign a virtual IP to one NIC. Basically I copied ifcfg-eth0 and makde ...
-1
votes
2answers
212 views

Is there an IP v4 address that can never be assigned? [closed]

I am aware of the difference between public and private ipv4 address space. My question is, is there a valid (in terms of DNS) IP address which will never be resolved by definition? localhost or ...
1
vote
2answers
258 views

IPv4 as default IP in dual stack [closed]

I am having an issue in prioritizing my IP network in Windows 8 to use IPv4 as default. Currently when ever I browser IP detection sites, they show me IPv6 address. How do I change this behavior?? ...
1
vote
2answers
517 views

Can a global IPv6 address be NAT'd to an internal IPv4 address at a firewall-level?

As an organisation we've just requested our first IPv6 allocation. At present we are a wholly IPv4 organisation with a global IPv4 address allocation configured on our edge router and used ...
2
votes
3answers
670 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
1answer
161 views

Add IP addresses on CentOS 6

I have a 12 IPv4 addresses that I need to add to a CentOS 6.3 machine however those 12 IPs are spread out among 3 different subnets. I know how to add additional IPs when they are on the same subnet, ...
1
vote
0answers
175 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, ...
4
votes
2answers
560 views

IPv4 NameVirtualHost, IPv6 VirtualHost

Like many of us, I have an apache server (2.2.15, plus patches) with a lot of virtual hosts on it. More than I have IPv4 addresses, to be sure, which is why I use NameVirtualHost to run lots of them ...
0
votes
1answer
651 views

How to enable TCP/IPV4 disabled on LAN via command prompt [closed]

I have unchecked tcp/ipv4 protocol from LAN properties & now iam unable to access the server or connect remotely. However i have serial console access to the server where i can use netsh command. ...
5
votes
1answer
486 views

IPv6 working fine, IPv4 throws OpenSSL error

I am building a webserver ( http://blog.linformatronics.nl/ ), which functions just fine on both IPv4 and IPv6 and when using a non-SSL connection. However when I connect to it through https, IPv6 ...
4
votes
2answers
178 views

Empty AAAA DNS Record with long TTL?

I pay for a DNS service based on queries per second. We are not using IPv6, but a large number of queries (that I pay for) are coming in for AAAA records. I understand that most DNS stacks will now ...
0
votes
1answer
538 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
546 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 ...
2
votes
0answers
279 views

Routing not working with OpenVPN

I'm trying to setup an OpenVPN server but I'm stuck with routing problem... This my network configuration: Client(172.17.17.6)<->Router+Firewall<->OVPN Srv(WAN:197.174.211.77)<->Subnet A ...
0
votes
2answers
136 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 ...
0
votes
1answer
74 views

Running IPv4 program in IPv6 network

I have an IPv4 windows client program and IPv4 Linux server. What I need is to run them in pure IPv6 network, although machines have dual stack. At the beginning I thought it's not a problem: I'll ...
1
vote
2answers
244 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, ...
0
votes
1answer
679 views

Which software could I use to setup a 4in6 IP tunnel (RFC 2473) on GNU/Linux

Here is my problem. I have a server A that has two IP addresses. One public IPv4 and one IPv6. Server B has only one IPv6 address. I want to host most of my services on server B (because I have more ...
2
votes
2answers
12k 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 ...
148
votes
13answers
24k 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), ...
1
vote
2answers
314 views

IPv6 very slow while IPv4 not on same server

I have a development and a production server, both running CentOS, on the same network with similar configurations. On one (the production server), when I do a curl, it attempts IPv6 first, but that ...
0
votes
1answer
446 views

Transparent SOCKS5 proxy for linux using dual stack IPv4 and IPv6

Can you recommend a SOCKS5 proxy for linux that can accept IPv4 requests, but connects to the internet using dual stack (IPv4 and IPv6)? It is going to run on Ubuntu with dual stack enabled. I ...
0
votes
2answers
174 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?
20
votes
3answers
5k views

What is the rest of the 127.0.0.0/8 address space used for?

We all know what 127.0.0.1 is used for (loopback). But is the rest of the reserved 127.0.0.0/8 loopback space widely used for anything?
1
vote
2answers
267 views

IPv6 connections routed to IPv4 device

I have an IBM 9406-250 with V5R1 and IPv4 only connectivity, and want it to be reachable over IPv6. I cannnot install an IPv6 stack on it, but I want it to be accessible by IPv6 so I can drop the ...
2
votes
1answer
43 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 ...
1
vote
1answer
146 views

LAN full of public ipv4 addresses - How to filter it?

The answer to my question maybe is not that hard but anyways, I do not know what to do. So, I just got in a new job in a Univerisity and I found out that the network (the LAN) is full of public IP ...