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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4
votes
2answers
250 views

For IPv6 migration, should we replace existing L2 switches running VLANs?

My L3 Core switch, Nortel ERS 8600, is IPv6 compatible. However, during migration to IPv6, do we need to also check the compatibility of edge/distribution switches in a VLAN-based campus network?
-1
votes
0answers
28 views

Route public subnet to client over openVPN

I want to route a public /29 subnet over vpn to a client with a natted ipv4. After doing some research, I can't figure out to make that work. Maybe I was searching for the wrong terms, but it seems ...
0
votes
1answer
21 views

Ubuntu 12.04 services using ipv6

I currently manage two servers on Linode. The first "server-a" is running 12.04, the second "server-b" is a fresh install of 14.04. A while ago I had some trouble with spf records on server-a and ...
0
votes
1answer
22 views

Dual-Stack Lite and FTP connection via IPv4 - How?

my original question: FTP client/server failing on switching to PASV mode Based on that, I would like to know if/how I can open a FTP connection from a computer that is inside a ISP's network that ...
1
vote
2answers
33 views

How can I change metric of public network in route table

In my windows 8.1 ENT [64 bit] machine I have 3 network adapters. Ethernet 1 is connected to public network and other 2 ethernet adaptors are connected to different internal networks. The problem is ...
1
vote
0answers
15 views

IPv4 header options handled different in Win7 and WinXP

If I send an ipv4 packet with (non standard) options to a WinXP host, it works as I expect it to do: The packet is handled correctly. If I send the same packet to a Win7 host, the packet is answered ...
-1
votes
1answer
31 views

how to 2 ip virtual in public dan private with forward to different destination

Here my case, Server 1 public IP in 1 box (eth0) -> 203.x.x.55/28 and 57/28 gw 203.x.x.49 private IP (eth1) -> 10.10.8.1 Server 2 private IP in 1 box (eth0) -> 10.10.8.5/24 and 7/24 gw 10.10.8.1 ...
2
votes
2answers
75 views

IPv6 servers and IPv4 client base

As IPv4 addresses are running out rapidly, a time will come when there will not be even single IPv4 address available for allocation. But, huge number of devices will still be running on IPv4. ...
0
votes
1answer
64 views

Making a reverse zone file on a 255.0.0.0 subnet

I’m trying to setup a reverse zone file for this subnet that has two hosts on it: 10.10.100.10 and 10.128.5.10. This means he netmask for the subnet would be 255.0.0.0. I inferred that the file name ...
0
votes
1answer
79 views

can I use DNS with private NAT addresses?

I want to build a service that dynamically creates VMs and assigns each VM a public DNS record which could be a full domain or a subdomain. Assume the VMS all live on a single host. The VMs will have ...
2
votes
2answers
80 views

Logging the outgoing port for IPV4

I need to become an IPV4 and IPV6 expert in a couple of hours. Our company is being bullied by the internet legislator in our country to move fast to offer the site in IPV6 only (we are just content ...
0
votes
1answer
134 views

Route IP to OpenVPN client

I have to external IPv4-IPs at my VPS. I want to route one to a VPN client, OpenVPN (tun). Only one VPN-Client should use the VPN, and I want to route all traffic to my second external IP to this VPN ...
0
votes
1answer
76 views

Attack from strange IP address, how to block?

Looking through the mail logs I've noticed a lot of these: Apr 7 11:33:25 s123456 pop3d: IMAP connect from @ [::ffff:192.96.206.9]checkmailpasswd: FAILED: web14p3 - short names not allowed from @ ...
0
votes
1answer
42 views

iptables NAT forward range

I have two network interfaces, eth0 and eth1. eth0 has a public ip, eth1 has 172.16.0.254/24. I'd like to do the following mapping: 172.16.0.1:22 -> eth0's public ip:2001 172.16.0.2:22 -> ...
1
vote
1answer
87 views

4in6 tunnel for heterogeneous systems [closed]

I have clients (OS X 10.9 and Linaro/Ubuntu) in a native IPv6 network and a Server (Debian) in both native IPv4 and IPv6. The Plan is to use the Server as a gateway of sorts, as in 4in6 ...
-4
votes
2answers
154 views

Exercise regarding public IP address and its “class C” [closed]

An exercise I am doing asks the following:- Identify what your public IP address is. Using public information sources, see what you can learn about your IP. If you don'ʹt find anything on your ...
0
votes
1answer
32 views

change timeout for dropped ip traffic

I am behind a corporate firewall, which simply drops (swallows) all ip-traffic to unknown ip-addresses. It takes a lot of time for Linux (Ubuntu 13.10) to abort my erroneous connection-attempts, ...
2
votes
1answer
42 views

Should we accomodate a customer asking us to NAT servers behind new PUBLIC IPs within a VPN?

We're a SaaS provider, setting up a IPSec VPN between our data center and a customer's site so they can directly access their hosted database server from their LAN. Instead of exposing our internal ...
7
votes
7answers
841 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 ...
0
votes
0answers
109 views

Repair RRAS and NAT on Windows Server 2008 R2

We have a Windows Server 2008 R2 server with RRAS installed and configure with VPN and NAT. NAT stopped working and when I checked, IPv4 is missing . I've tried re-installing RRAS but it just ...
1
vote
1answer
81 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 ...
0
votes
0answers
309 views

Configuring DHCP IPv4 and static IPv6 on the same interface

I need to configure on a network interface (eth1) with static IPv6 and get an IPv4 address from DHCP on a CentOS 6 machine? Using the configuration below I only get a dynamic IPv4 address: ...
1
vote
2answers
57 views

Make NginX serve different pages depending on the IPv4 encoding base

You can access google on 186.215.155.54 , 0xBAD79B36 or 3134692150 (remember to put http:// before if you want to try). How is the base conversion handled by the browser? Is there any way for NginX ...
2
votes
1answer
178 views

Dell VRTX get ip address of server attached to chassis

I wanted to know if there is any racadm command to get the ip address of the attached server's in a dell VRTX chassis. racadm getslotname will give the Host Name of the server but not the ip ...
1
vote
5answers
373 views

What constitutes valid justification for more IP addresses?

I host a small website with a well known VPS service. They provided me with one IPv4 address upon registering and said additional addresses would require justification. I requested one additional IPv4 ...
-1
votes
2answers
143 views

Cannot browse ipv4 websites (OpenVPN )

I have set up an openVPN tunnel on my VPS (OpenVZ - Ubuntu 12.04). The problem is when I'm connected to the vpn, I can only browse websites which support ipv6 like google. Ipv4 sites aren't loading ...
-1
votes
1answer
116 views

Setup IPv4 local on IPv6 VPS

I have a dedicated server running multiple IPv6 only OpenVZ containers. I want them to be able to communicate with the IPv4 internet, but I realized that isn't going to be possible with IPv6 only. So ...
2
votes
1answer
146 views

IPv4 header vs IPv6 header size

Just wondering from looking at that picture if Total size = payload size and the IPv6 header is bigger, does that mean Ipv4 packages can contain more data?
4
votes
1answer
741 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' > ...
2
votes
1answer
93 views

Why doesn't this IPv6 listen directive also accept IPv4?

In my nginx (1.4.2) setup on Ubuntu 12.04, I have set up only one configuration file (I deleted/disabled the others): server { listen [::]:80 default_server; location / { root ...
0
votes
1answer
429 views

/etc/init.d/iptables-persistent start returns fail but seems to work

I am trying to activate iptables-persistent on an Ubunutu server. Config files are located in /etc/iptables/rules.v4 /etc/iptables/rules.v6 I have installed the iptables-persistent package. ...
1
vote
1answer
435 views

How to do dual stack IPv4/IPv6 with virtual hosts on nginx 1.4

I'm using nginx 1.4.1 (now, before it was 1.2.1) and would like to support dual stack (IPv4 and IPv6). I'm always getting duplicate listen options for xyz errors from nginx. server { listen 80 ...
1
vote
1answer
224 views

SPF: softfail (domain of transitioning email does not designate 2a01:4f8:121:2062::2 as permitted sender)

I am seeing this SPF softfail for emails sent from my server, and I notice that 2a01:4f8:121:2062::2 is an IPV6 address. When I check 2a01:4f8:121:2062::2 it is translated as 0.0.0.2 ipv4, so that ...
1
vote
3answers
266 views

ipv6 on Ubuntu server - how do I secure?

On our Ubuntu server, ipv4 & ipv6 are enabled. We have taken these steps so far. Enabled iptables & ip6tables Copied the rules exactly from our iptables to ip6tables Do we need to make ...
0
votes
2answers
113 views

IP Routing with 2 Subnets

We currently have a Cisco ASA on a range with only two usable IP addresses. The Cisco has 217.67.255.31 and the BT NTE box (for the leased line) has 217.67.255.32. (on /32) Now we want to split this ...
2
votes
1answer
279 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
90 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
68 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
124 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
406 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
65 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
178 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
95 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
379 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
1k 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
175 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
3k 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
138 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
122 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
110 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 ...