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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31 views

Delayed Ping of a link-local address with Windows 7/Server 2008 R2/Server 2012 R2

I have a strange effect here, which I do not understand. PS C:\Users\user1> ping fe80::219:bbff:fe0e:c600%16 -t Ping wird ausgeführt für fe80::219:bbff:fe0e:c600%16 mit 32 Bytes Daten: Zielhost ...
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12 views

What changes with Kerberos Authentication in IPv6 when using NAT? [duplicate]

How should Kerberos Authentication be setup with IPv6? Of you're using NAT for IPv6 where there is a single public IPv6 address and it translates to the machines inside in the ULA range?
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1answer
29 views

What changes with Kerberos authentication in IPv6 when everyone has a public IPv6 Address?

How should Kerberos authentication be set up with IPv6? What implications are there when client devices each use a public, globally routeable IPv6 IP address? What changes when setup this way ...
0
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1answer
153 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 ...
0
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0answers
28 views

Allow outgoing traffic behind ipv6 firewall behind router

I am working on configuring ipv6 traffic for a project and I am running into a problem. When I try to ssh from the machines that are behind the router into the router, it blocks the connection. I ...
2
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1answer
62 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
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0answers
95 views

IPv6 Routing // Destination unreachable: Beyond scope of source address

I want to setup Dual Stack on Customer VMs. The Router is a VM too. Running on Debian Wheezy. Overall virtualized by ESXi. IPv4 is working fine. Ping from Customer VM ping6 -c 1 heise.de PING heise....
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1answer
40 views

Linux host does not retransmit with a lower packet size in response to ICMPv6 Packet Too Big message

I'm seeing this in Wireshark when curling this URL: On the same network, a Windows host retransmits properly, but an Android host does not. On a different network (presumably appropriately ...
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0answers
80 views

IPv4 over IPv6 IPsec tunnel

I've got two Cisco 2811 routers, both with a global static IPv6 adress, and an IPsec tunnel between them (using VTIs). Is it possible to send IPv4 traffic over this tunnel? The relevant parts of the ...
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1answer
53 views

How to force Centos to use ipv6 interface only?

My Centos server has two virtual (Openvz) interfaces. One from these interfaces has ipv4 address configured, while the other one has the ipv6 one. In short this server is used for browsing / proxy. ...
1
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1answer
21 views

Manually Assigning Site Local IPv6 Multicast Address to DHCP Server

According to https://en.wikipedia.org/wiki/IPv6_address#Multicast_addresses, ff05::1:3 is a site local multicast address for All-dhcp-servers. Based on this, when I add the DHCP role to a Windows ...
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0answers
17 views

Assigning Prefix-Flexible Static IPv6 Addresses to Servers

Sometimes it's desirable to assign a server a static IPv6 addresses. Hand-configuring a static global unicast IPv6 address is one way to do this but necessitates manual updating any time the address ...
1
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0answers
88 views

Ensure systemd wait for IPv6 before start service unit

When I have a service listening on a specific IPv6 address, it fails on boot, claiming that the address is still not available. This happens to every service that is listening on specific addresses. ...
1
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1answer
133 views

SOA record in AAAA query reply when IPv6 is not supported

When I do dig AAAA to a website that doesn't support IPv6 yet, the reply has an SOA record. Is it a requirement to have the SOA record in response to a AAAA query when the service doesn't support ...
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1answer
79 views

IPv6 + PTR + gmail returning error

I have a problem with mail connected to gmail account. Every time when i wanna send mail i got that error: Our system has detected that this message does not meet IPv6 sending guidelines regarding ...
0
votes
1answer
106 views

AWS ELB with ipv6 fails on online tests

I have an ELB with ipv6 AAAA DNS configured on route 53. The problem is that the tests I used tell me it's not ok (I don't have an ipv6 connection for testing): AFAIK I don't need to configure ...
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0answers
37 views

IPv6 Ping is unsuccessful when IP is obtained from DHCP server

I just faced this problem and it's driving me crazy. I have DHCP server for both IPv4 and IPv6. IPv4 works like a charm but the problem is IPv6. My client gets IPv6 (fc50::a9 to be exact) from DHCP ...
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0answers
40 views

Very slow outgoing requests, from **some** servers

In this case, it's an HTTP request to https://www.instagram.com/, but it has happened before like this. From my home (Ubuntu, i686) server it's very fast (~ 0.3 sec). From my online, modern (Ubuntu, ...
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0answers
91 views

IPv6 is not working between two OpenWRT devices

I have 2 problems lately regarding IPv6: My ISP doesn't provide an IPv6 prefix (even with modem in bridge, and yes the ISP supports) so, I'm using SIXXS tunnel , it doesn't attribute IPv6 to another ...
0
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0answers
78 views

How to avoid curl trying IPv6 name resolution

From a docker container when I try to curl 'another container name', curl first tries to resolve the name to IPv6. This causes few seconds delay because the web server is not reachable over ipv6. I ...
0
votes
0answers
345 views

IPv6: Destination unreachable: Address unreachable

My server can't ping/reach any other outside. ping6 works for my local fe80::468... address as well as the 2a01:4f8..., but not for fe80::1! Errors/Troubles/Issues: ip neigh show fe80::1 dev eth0 ...
0
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0answers
75 views

HAProxy configuration problems (with source directive)

I have HAProxy setup to listen on a public IPv4 address (1.2.3.4), it is supposed to proxy all requests to my b_http backend. The back-end has a source line that makes it connect to the server/site ...
2
votes
0answers
80 views

Is it possible to configure HAProxy to listen on IPV4, but send the request using IPV6? [closed]

Trying to configure HAProxy to listen for requests on port ipv4(Port 80) but proxy the request through eth1 to a server using ipv6. The request must be show the ipv6 address for the request. We don't ...
0
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2answers
44 views

IPv6 DNS Connectivity through IPv6

My clients are using IPv4 in the USA. Their ISP is not ready for IPv6 yet. My public web server is on only IPv6. It is registered with a DNS Provider(GoDaddy) that is IPv4 and IPv6 enabled. Can my ...
0
votes
1answer
48 views

Fixed Size of IPv6 SLAAC

My confusion with IPv6 SLAAC is that the router provides the network prefix, and the host generates its own part using EUI-64, which means it is always going to be a 64-bit address. Now, SLAAC is ...
1
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1answer
62 views

Understanding IPv6 Address

My IPv6 address is like this (some digits changed): 2001:569:78f0:ca00:bcaa:d016:4 ...as reported by whatismyipaddress.com. This is strange because I understand that there should be eight blocks ...
1
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1answer
140 views

HTTPD listening in IPv6, according netstat, but reacheable in IPv4

Using Openstack, I have a Web GUI (horizon) hosted on my server (HTTPS). When I do a netstat -lt | grep https, I have: tcp6 0 0 [::]:https [::]:* LISTEN ...
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votes
1answer
88 views

How to add IPv6 /64 block to lo (local) interface permanently

I'm using this command line to add /64block IP range to lo network interface. ip route add local 2001:bc8:1234:abcd::/64 dev lo But, when I'm reboot my server. It requires again to execute that ...
1
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0answers
33 views

Multiple IPv6 addresses added to interface, now IPv6 not working on my server [duplicate]

I got /64 IPv6 block from my server provider. When I add few IPv6 addresses (maybe 10 or 20) to network interface. Everything works fine about IPv6 network. When I'm added above 500+ IPv6 addresses ...
0
votes
1answer
338 views

Nginx proxy_pass always sending to [::1]

I am having problems with redirection from Nginx to gunicorn. I'm using proxy_pass to redirect to https://127.0.0.1:5000, and yet the redirect is being sent to https://[::1]:5000. Here is my own ....
2
votes
0answers
162 views

How to use an IPv6 Edge router in an IPv4 network?

Background I have the following set-up: I use 6LOWPAN (IPv6 implementation in IEEE 802.15.4) on my sensor link that have IPv6 addresses (stateless) as aaaa::xx/64 It uses RaspberryPi (RPI) as an ...
0
votes
0answers
50 views

ipv6 forwarding in linux failing

I have following ipv6 network in my system. X2 & Y2 interfaces belong to Linux and are physical interfaces. X1 & Y1 are external devices. (2000::10)X1<-----------------> X2 (2000::12)(...
6
votes
1answer
230 views

Should I put Scope:Link or scope:Global IPv6 address in DNS AAAA record?

I have a mail server for which I need to create the AAAA DNS record and update the SPF record to include its IPv6 address. An ifconfig command shows a Scope:Link IPv6 address and a Scope:Global IPv6 ...
0
votes
0answers
36 views

ubuntu: add 1000 ipv6 addresses on if-up

I'm trying to configure 1,000 IPv6 addresses using if-up.d. However, when the server is rebooted, they aren't configured properly and eth0 isn't up, even though I'm still able to connect to the server ...
7
votes
5answers
392 views

No IPv6 & DNSSEC support on cc-TLD? (practical implications)

I'm needing to register some domains that have country code domain extensions, but noticed that those TLDs do not officially support (A) IPv6 or (B) DNSSEC... What limitations or pitfalls should I ...
0
votes
0answers
11 views

Is it possible to setup a range of secondary IPv6 addresses in Centos? [duplicate]

Rather than declaring secondary IPV6 addresses one by one in the ifcfg-* file, and get a very long IPV6ADDR_SECONDARIES="...." line, it is possible to declare a range of IPv6 address with a /prefix ...
5
votes
1answer
262 views

Apache (Linux) httpd listen on link-local IPv6 address

I would like Apache to listen on the link-local ipv6 address on a particular interface. I have the following line in my httpd.conf: Listen [fe80::a00:16ff:fe89:420f]:80 Which is based on the Apache ...
1
vote
2answers
135 views

Some IPv6 hosts send all traffic, even in same subnet, to router

I noticed a routing issue with IPv6 with our LAN. Most of the client PCs are LTSP thin clients. They get one address through SLAAC. Tracepath6 to hosts on the same subnet shows all traffic is direct. ...
0
votes
1answer
55 views

Autoconf from /etc/network/interfaces is not working

I want to disable autoconf of IPv6 for which I am making entries in /etc/network/intefaces file as below. Before making this changes I use "ifdown eth0" iface eth0 inet6 static address <...
1
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0answers
38 views

What is the significance of a router advertisement prefix with L and A bits set to 0?

RFC 4861, section 4.6.2 describes the prefix option for router advertisement packets. There are two flags that are part of that option L and A which indicate the prefix is usable on-link and for SLAAC ...
0
votes
0answers
56 views

CentOS 7 machines can't ping each other over ipv6

I got three machines configured for ipv6: CentOS 7 vm1 - 2602:306:cc2d:f591::a/64 CentOS 7 vm2 - 2602:306:cc2d:f591::b/64 Macbook - 2602:306:cc2d:f591::c/64 The two VMS are on the same host (a ...
2
votes
1answer
93 views

PTR record format for IPv6

What is the difference in the following two IPv6 PTR formats? 4.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0 IN PTR smtp.example.com. 4.3.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.0.0.0.a.4.f.7.0.6....
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0answers
65 views

Windows Server 2012 Local DHCPv6 Stateful & Public Stateless?

I want my LAN to have static IPv6 ULAs from the server's DHCP6, and global IPv6 as well. So it'd look something like this: Server IPv6 Address. . . . . . . . . . . : 2601::1 (public auto) ...
0
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1answer
22 views

How to setup this IPSec VPN?

I have a main network (Net-A), there my work should be done there. On the other network, I have host server where it can reach to Net-A. On the host server, I'll create a couple of virtual machines, ...
0
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1answer
32 views

SSH Connection reset on IPv6

When attempting to SSH from an IPv6-enabled host to an IPv6-enabled host, I get: $ ssh remotehost.example.com ssh_exchange_identification: read: Connection reset by peer When I add the -4 option, ...
2
votes
0answers
66 views

Route single IPv6 address using router advertisement

I have a server in my local network that connects to an external VPN server and gets assigned the public IP address 2a02:c200:1:10:3:0:4315:2. Currently, when other computers in my local network ...
25
votes
2answers
2k views

Why is IPv6 adoption higher at weekends?

Look at the graph of IPv6 adoption rates maintained by Google here: https://www.google.com/intl/en/ipv6/statistics.html Zoom in to the September to December 2015 period. The graph of IPv6 adoption ...
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1answer
65 views

IPv6 resolving as loopback/private IP

I'm running a web crawler and I received some reports from my datacenter about connections directing to private IPs (like 10.0.0.1). I've implemented a loopback/private ip check to my crawler code and ...
3
votes
1answer
96 views

Cannot bind to a specific IPv4 address when making outbound TCP connections, to hostnames that resolve to both IPv4 and IPv6 addresses

I just spent about 6 hours trying to figure this out, and I now believe CentOS/Linux is unable to bind to a specific virtual IPv4 address when connecting to a hostname that has an IPv6 address. This ...
2
votes
0answers
133 views

Nginx proxy_pass to upstream uses sometimes IPv6 address

Why does Nginx proxy_pass to upstream send sometimes outgoing requests to IPv6? 2015/12/28 14:11:06 [error] 38194#0: *114469948 connect() failed (111: Connection refused) while connecting to upstream,...