IPv6 is the successor to IPv4. Rather than 2^32 addresses (like IPv4), it has 2^128, which is 340,282,366,920,938,463,463,374,607,431,768,211,456 unique addresses (34 undecillion). IPv6 addressing is quite different to IPv4 and is not backwards compatible, but protocols that sit on top (HTTP, SSH, ...

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1answer
1k views

Automatically acquire IPV6 address in CentOS 6

The network has fixed IPv4 address, and automatic acquired IPv6 address. Does anyone have an idea how to setup? Thanks a lot! I didn't use NetworkManager. The following is my setting, but it does not ...
1
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0answers
48 views
+100

CentOS 7 connectivity issues

I have a second CentOS 7 box that's having a lot of trouble connecting. Basically, we were running WHMCS, but a domain lookup kept failing. So the issue is IPv6 connectivity. [root@da01 ~]# yum ...
-1
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0answers
22 views

Why do IPv6 addresses use colons?

Colon is already used to separate host and port, so you can't just turn "hostname or address literal" into a "host:port" string without special-casing IPv6 literals and escaping them using square ...
0
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0answers
23 views

Can IPv6 connectivity between countries be unreliable?

I’m setting up IPv6 on my existing VPS and backup server. The VPS is located in Fremont on Linode, and the backup server is located in New Zealand. I have several VPSs within the Fremont data center. ...
4
votes
1answer
45 views
+50

No IPv6 connectivity from docker container

i'm having serious problems enabling IPv6 in docker. Environment The host is running Debian Jessie. It's a virtual Server (KVM). eth0 has a statically configured address like w:x:y:z::1 in a ...
0
votes
2answers
14 views

setting IPv6 address for domain

I am quite new to the server business and I was wondering about a thing with the IPv6 addresses: When I assign an IPv6 address for my domain as an AAAA record: Do I assign a /64 address or do I ...
0
votes
0answers
23 views

How to assign ipv6 to my kvm guests route mode

Do you know how assign ipv6 global addresses to my KVM Guests?My ISP provider advertise an ipv6 prefix /64.I use libvirtd an here is configuration. When i restart virbr0 cant communicate with local ...
9
votes
1answer
79 views

With IPv6, should we be assigning distinct IP addresses to each host name served over HTTP(S)?

With IPv4, it's pretty much a given that unless there is some specific need that warrants IP-based virtual hosting, name-based virtual hosting should be done to avoid needlessly exhausting the address ...
6
votes
1answer
395 views

Is this IPv6-link-local address (as reported by Windows) correct? If so, why?

From what I read online, an IPv6 link-local address is generated by taking the network interface's MAC address, inserting an FF:FE word into the middle of it, OR'ing in some additional bits, et voila: ...
0
votes
1answer
26 views

IPv6 connection between 2 computers doesn't work

I have 2 Linux computers with the following IPv6 addresses: 1: fe80::de0e:a1ff:fe15:13e0 prefixlen 64 2: fe80::2e0:4cff:feb0:f8d prefixlen 64 When on the first computer I try: # ping fe80::2e0:...
0
votes
1answer
35 views

SSH connection is slow and buggy when connected by IPv6

I noticed that my SSH session is not usable (random connection errors, hugh delay, etc.) when I'm connected by IPv6. I'm not connecting to my server by IPv4/IPv6 addresses directly. I use my domain ...
0
votes
0answers
59 views

Openvpn client frequently uses a different IPv6 address causes a unstable connection

I set up an OpenVPN server on IPV6 recently, it runs well, except for one thing: the client loses connection frequently for Inactivity timeout (--ping-restart). Here's the log infomation on the client....
0
votes
1answer
41 views

IPv6 - Allow incoming ICMP echo requests

So, we recently got our /48 prefix from our LIR, and started small-scale deploying it in a lab. What struck me as odd is that sites like http://ipv6-test.com/ insist that you allow incoming ICMP Echo ...
0
votes
1answer
256 views

Enable DHCPv6 in dnsmasq to distribute fixed range IPv6 addresses but failed

Help wanted! I want to create a AP in my Raspbian PI. And i choose dnsmasq as the dhcpv4 and dhcpv6 server. However, my laptop can acquire IPv4 successfully but fail to get a IPv6. Why the dnsmasq ...
26
votes
2answers
17k views

Should I use IPv6 only or both IPv4 and IPv6 in my web server?

My web server (Ubuntu, Nginx) have both IPv4 and IPv6 addresses assigned by the host. For my website, shall I bind it to only an IPv6 address? Is it the standard recommended way? Or, shall I use both ...
0
votes
0answers
14 views

Configuring Dante for multiple ipv6 proxies

I'm trying to setup multiple ipv6 socks5 proxies with a single server (not sure if this is possible) using dante. My end goal is to be able to connect the the socks proxy and have my visible ip to be ...
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votes
0answers
37 views

Host a 6in4 Tunnel Server on CentOS 7

I want to host a 6in4 tunnel server on CentOS 7, rather than using TunnelBroker to enable IPv6 connectivity for my home network. I tried lots of answers already: Set up a 6in4 tunnel server http://...
1
vote
1answer
107 views

UDP hole punching still required in IPv6, even without NAT?

Background (skip ahead for question) IPv4 needed NAT for address conservation. The firewalling properties of NAT were also beneficial for security. IPv4 NAT firewall rules are "block incoming packet ...
1
vote
1answer
32 views

IPv6 and LXC connectivity

I am struggling a bit on how to equip my LXC configuration with IPv6 currently. What's the setup? Ubuntu 16.04 LTS LXC2-beta from the Ubuntu PPA's (feature IPv6 connectivity) I use a netcup IPv6 ...
0
votes
0answers
5 views

How do I use mDNS for ssh -6? [migrated]

Hello I have the following setup: Ubuntu 14.04 LTS Laptop A lot of Raspberry-Pi Model 2 with WLAN The complete setup is based on 802.11 WLAN AD-HOC mode. None of the Pis nor the Laptop uses any ...
0
votes
1answer
37 views

IPv6 Subnet Delegation

I'm a bit confused on how to calculate IPv6 numbering. I have a /32 now and a VPN client that wants 6 x /48 from that /32. Could someone please simplify on how I can determine the points of the /32 ...
1
vote
2answers
95 views

Is it possible to use IPv6 in my local network if my ISP is using IPv4

My ISP is using IPv4 and assigns IP addresses via DHCP. Is it possible for me to use IPv6 in my local network/subnet, and if so is it even worth it to do so?
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votes
1answer
37 views

Best way to forward whole ipv6 /64 subnet range to single address (on Linux, obv)? [duplicate]

I want to forward incoming connections to any address within an assigned ipv6 /64 subnet on a VPS. Obviously I can't add a billion individual address to the interface, but perhaps I could use a bogus ...
0
votes
0answers
33 views

Cannot reach server using IPv6 Nginx Config

I was setting up SSL certificate and I tested them : https://www.ssllabs.com/ssltest/analyze.html?d=gfelot.xyz I was surprise to cannot connect with IPv6. I try in my browser : http://[2001:41d0:3:...
1
vote
1answer
43 views

Websocket reverse proxy with nginx: Error about request in server log, but works in browser

The situation I am running Etherpad, which is proxied via nginx. Etherpad uses Websockets with Socket.io. My nginx config is more or less this one. The location block for socket.io is this: rewrite ...
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votes
3answers
53 views

Which ipv6 address to use for AAAA record [closed]

My VPS provider provides me with one ipv4 and 17 ipv6 addresses. Is there any right or wrong ipv6 address from the 17 given to use as AAAA record ?
0
votes
1answer
60 views

why teredo IP Address keep changing?

I managed to configure teredo on windows 7 but I come up with one problem ... teredo IP address keep changing . I noticed that terendo stat keep change too , it moving from dormant to enabled and ...
2
votes
1answer
21 views

Adding an IPv4-only Domain Controller to an existing pool of Domain Controllers with both IPv6 and IPv4

We have an existing pool of Windows 2008 R2 Domain Controllers on-premises. These Domain Controllers have IPv6 and IPv4 configured. Now we need to add another Domain Controller that will seat on an ...
5
votes
3answers
32k views

What Causes IPV6 To Be Used Instead Of IPV4?

I have two servers both running Windows 2008 with IPV4 and IPV6 both running. If on server1 I ping server2 like this ping server2 The response I get is Pinging server2 [2002:9b08:a21::9b08:a21] ...
0
votes
0answers
93 views

IPv6 not working

I'm unsure as to why this is happening... anyway, let me start from the beginning The Setup 1 * Dedicated server with a /29 IPv4 and /48 IPv6 (from Nocix (DataShack)) 1 * CentOS 7 KVM host 1 * ...
0
votes
0answers
27 views

6in4 Tunnel with /80 Addresses

I want to setup my own 6in4 tunnel server on CentOS 7, my VPS ISP can only provide a /80 IPv6 block addresses while I can see most of tutorials said it requires /64 for client's DHCP server to work. ...
0
votes
0answers
21 views

Can't reach centos server after “Multicast listener report” IPV6

I ran into a problem that occurs only on a few servers. Every 5-6 minutes I lose connection to the server, and it get backs after a few minutes. In most cases it's a VM that is not reachable while ...
1
vote
2answers
52 views

Debian / IPv6: Default route expires after 1800 secs, loosing connectivity

I'm running Debian 8 on a vServer. After installing docker and enabling IPv6 i noted something strange. I don't know if docker has anything to do with this, it's just that i noticed this problem after ...
0
votes
1answer
124 views

Hyper-V vm can ping host but host cannot ping Hyper-V vm?

When ping host from hyper-v VM, it works both with ipv4 or ipv6. Pinging MyHost [fe80::3549:ee49:a75c:619c%9] with 32 bytes of data: Reply from fe80::3549:ee49:a75c:619c%9: time<1ms Reply from ...
4
votes
5answers
2k views

How to bind a non-local IPv6 address?

Is there an equivalent of net.ipv4.ip_nonlocal_bind for ipv6 ? Need to start my nginx on boot on such an IP... My Ubuntu doesn't have this IPv6 assigned on eth0 quickly enough despite this /etc/...
9
votes
2answers
7k views

IPv6 DHCP Configuration

I want to set up an IPv6 only network for testing. However, I can't find any HOWTOs or information on setting up DHCP to autoconfigure IPv6 DNS server addresses etc. I use radvd on a ubuntu server to ...
0
votes
1answer
117 views

Firewalld blocks IPv6, ignores config

I'm trying to setup an IPv6 web-server on CentOS 7.2 with NGINX. I have tested my IPv6 connectivity outgoing and incoming - everything works. My IP, AAAA records, etc as fine as well. Essentially ...
-1
votes
1answer
60 views

Building router with one ethernet interface

Good day! I have 2 servers in datacenter and I want to use one of them as router for another instead of default gateway provided by DC. Both servers have one ethernet interface called 'eth0' with ...
-1
votes
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 ...
0
votes
1answer
30 views

Allow outgoing IPv6 connections for VPN clients

I have the OpenVPN server. A client connecting to this server receive an internal IPv4 address (10.2.52.X) and an external IPv6 address. I need to perform a masquerading (NAT) for IPv4 but I don't ...
4
votes
1answer
1k views

Mikrotik: how to properly setup IPV6 routing/dhcp server

I have the following configuration in my network: ISP Router <- eth1 -> Mikrotik Router <- eth2-5 -> Internal network My ISP router receives a /64 IPV6 block that is dynamic, changing ...
0
votes
0answers
34 views

IPv6 interface not responding to neighbor solicitations, DHCP involved too

ip addr shows: 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 02:6d:5e:86:29:49 brd ff:ff:ff:ff:ff:ff inet X.X.X.X/...
0
votes
0answers
42 views

Kamailio as TCP-only SIP register and relay

I have a rather complicated setup in which I'd like to run a SIP server. In general, I want to run an IPv6-only Kamailio SIP-server on internal network and have outside SIP-clients be able to make ...
0
votes
0answers
68 views

IPv4/IPv6 dualstack setup in Debian/Ubuntu via preseed

I use preseed to provision my Ubuntu 16.04 installation. It has the following options to set up IPv4 or IPv6 address # Static network configuration. # # IPv4 example #d-i netcfg/get_ipaddress string ...
1
vote
1answer
41 views

How to redirect traffic through IPv6 IPSec (strongswan) gateway?

I'm trying to set up IPSec secured connection to the gateway. Have three hosts: A: eth1 - fec0:1::1/64 B: eth1 - fec0:1::2/64 eth2 - fec0:2::2/64 which is gateway between A and C; forwarding is set ...
17
votes
2answers
1k views

Is an IPv6-only MTA possible yet?

Has anyone had tried to run an IPv6-only SMTP engine? Pretty much everybody with any sense has IPv6 configured for major front-end servers. I was curious if anyone had tried to run an IPv6-only MTA ...
4
votes
3answers
8k views

sendmail can not deliver to gmail - IPv6 sending guidelines regarding PTR records not met

I am having trouble in delivering mail to google from a fresh sendmail install on ubuntu 14.04. The DNS-records seem to be fine for the ip. Something else must be wrong. Sending mail from command ...
1
vote
1answer
232 views

OpenSSH adds <IPv6>%2 to known_hosts

When I connect to a CentOS 7 host with IPv6 my ssh client always adds <IPv6 host addr>%2 to known_hosts even though the host key for this host (with the host's IPv6 address) is already present ...
2
votes
1answer
57 views

Can Linux be made to honour IPv6 Route Advertisement preferences?

Bottom Line Up Front: I can't get a Linux box receiving RAs to use the RFC4191 "Default Router Preference" value to prefer higher-priority routes. Instead, whichever default route it learnt first is ...
1
vote
1answer
44 views

IPv6 and ESP as a next header

I'd like to know how to parse IPv6 header and get offset to TCP header and its payload. I know that IPv6 has fixed base header. I know also that there are several extension headers in IPv6 - among ...