6
votes
Purpose of IPv4 mapped IPv6 address
These mapped addresses cannot be used to make IPv6 connections. They are only usable to represent IPv4 connections in IPv6 software.
Say that you have a machine that is dual stacked with both IPv4 and ...
- 7,672
6
votes
Accepted
Should mail servers avoid sharing /64 ipv6 with others for reputation?
No, you should not go out of your way to make servers controlled by the same entity look less so. If systems can automatically make the connection that you are responsible for multiple addresses, that ...
- 8,095
3
votes
Accepted
While using pf on FreeBSD, do I need to explicitly specify both the inet and inet6 parameters?
If we take it for granted that the first rule looks like in the question, you would indeed need a separate rule for inet6 to also do the same for IPv6.
However, if the rules are otherwise identical, ...
- 34.4k
2
votes
IPv6 dynamic DNS client for Cloudflare
I'm not that familiar with Cloudflare's services as I normally try to avoid public cloud services, but as they're a CDN, you most likely can add an origin server via a DynDNS name. And then you can ...
- 131
2
votes
How to protect a web application from IPv6 bots?
You can do some really primitive IP subnetting via regex. Here, I am passing IPv4 addresses through unchanged but grabbing the first half of IPv6 addresses, which corresponds to the /64 prefix of the ...
- 381
2
votes
Routing traffic from a bridge to a specific interface
A bridge doesn't route. Bridging happens at layer 2, routing at layer 3. You'll have to make up your mind whether you want to route or to bridge between your internal network connecting the VMs (...
- 4,021
2
votes
Are there any additional security considerations to be taken into account when activating IPv6 as opposed to IPv4?
Can I use my IPv4 knowledge (and the basics mentioned above) to securely make an Internet service available to the public via IPv6
Yup, definitely.
There is, however, one major security consideration ...
- 8,500
2
votes
Docker containers can't talk to subnets but the docker host can, how do I find where the packets are being dropped?
The problem was to do with docker's networking. We had a docker network setup to use a network bridge to connect to the VPN. That bridge was setup (via /etc/network/interfaces.d/br0.cfg) with a ...
- 161
2
votes
Accepted
Migration from IPv4 to IPv6 - stable internal service addresses
I would personally go with ULA.
Use ULA with SLAAC (or DHCPv6 or static addresses, it doesn't matter) for internal services. Add name->ULA address mappings to your internal DNS.
When the router ...
- 3,305
2
votes
How to track down IPv6 DNS server configuration with Wireshark?
This is normally part of the RA messages:
This should be sent by the host sending Router Announcement messages, and you should probably configure the mechanism used for sending RA's with the ...
- 5,783
2
votes
Redirect nginx port 80 to http2 443 fails
Try replacing
server {
listen 80;
listen [::]:80;
server_name example.org;
location / {
return 301 https://$server_name$request_uri;
}
}
with
server {
listen 80;
...
- 33
1
vote
Accepted
How many public useable IPv6 ips in a /64 range?
That can not be answered like this because it does not depend on the /64.
An IP Address is 128 bit. 64 of that are the IP address within a network, the OTHER 64 bit are the network.
And the networks ...
- 51.4k
1
vote
Accepted
Allowing inbound IPv6 traffic to a host and port when the IPv6 prefix is dynamic?
ip6tables accepts a bitmask for the address. Unlike with iptables and IPv4, these bits don't necessarily all have to be at the beginning of the address, so something like this should work fine:
...
- 154
1
vote
Are there any additional security considerations to be taken into account when activating IPv6 as opposed to IPv4?
One of the most prolific authors in the IPv6 security domain is Fernando Gont. He (co-)authored several RFCs, Internet Drafts and other documents and gives talks on IPv6 in general and IPv6 security. ...
- 621
1
vote
Accepted
When using `xfrm` and strongswan for an ipsec tunnel, where are the routes stored?
https://docs.strongswan.org/docs/5.9/howtos/introduction.html#_routing tells:
On Linux, strongSwan installs routes into routing table 220 by default
and hence requires the kernel to support policy ...
- 9,670
1
vote
Accepted
Redirecting traffic via Wireguard VPN
Sounds like you just want to be able to connect from your Network Device to your Example Client, and vice versa? If so, then this is the classic Hub and Spoke WireGuard scenario, with the VPS as the ...
- 1,176
1
vote
Accepted
IPv6 routing on Linux
According to this previous question, you need to set net.ipv6.conf.all.forwarding = 1 rather than (or in addition to) setting the flag on individual interfaces, which is used for controlling router ...
- 156
1
vote
Give VM a static ipv6 address
A bit of an explanation to what I am getting at in the comments:
What I can gather is that you have a VPS that have native IPv6 connection and is residing on a /64 subnet.
On this machine you want to ...
1
vote
Can someone breakdown what the IPv6 address fd15:53b6:dead::2/64 is?
AWS copied the man page regarding block-ipv6, to illustrate an example of when you don't want IPv6 traffic outside of a tunnel (leaks), but the network is not IPv6 ready. Which apparently is currently ...
- 31k
1
vote
All IPv6 prefixes that should be routed by a public router
All Global IPv6 addresses are in the 2000::/3 range. There are a few ranges inside the Global address block that are not Globally Reachable.
See the IANA IPv6 Special-Purpose Address Registry. There ...
- 3,198
1
vote
Accepted
All IPv6 prefixes that should be routed by a public router
The 2000::/3 prefix is where all of the Global Unicast addresses reside and may be what you want. There may be other prefixes you could add (but it seems unlikely) see IPv6 Address Types.
- 115k
1
vote
Accepted
Configuring Ubuntu 22.04 to generate the interfacepart of an IPv6 staticly
IPv6 has a few choices for how to do stable IP addresses. Defining a static interface ID on the host. DHCPv6 where reservations persist. And a value that can be computed from known values, like EUI-64 ...
- 31k
1
vote
IPv6 Forwarding working 1 way externally
I can see one typo that would disrupt egress traffic:
-A FORWARD -i enp6s0 -o enp1so -j ACCEPT
The output interface name is enp1so while it should be enp1s0. The effect would be that incoming ...
- 9,670
1
vote
Accepted
How do I duplicate the default IPV6 routes to a second routing table in order to bypass a VPN?
The Linux kernel can cheat. It doesn't care itself when it automatically adds routes (proto kernel) with conflicting values in the same routing table. Those are usually the automatic prefix LAN routes ...
- 9,670
1
vote
Unable to reserve external IPv6 address on GCP
Not possible yet unless your GCP project is granted Alpha access to the feature:
https://cloud.google.com/compute/docs/ip-addresses/reserve-static-external-ip-address#reserve-regional-ipv6
Important: ...
- 111
1
vote
Channeling IPv4 packets to IPv6 packets between interfaces
IPv4 and IPv6 are different protocols, and cannot be directly routed between.
Move everything to IPv6 and you can have a single stack all the way through, which can be directly routed.
Or, tunnel IPv4 ...
- 31k
1
vote
Channeling IPv4 packets to IPv6 packets between interfaces
Routing cannot convert between IPv4 and IPv6. You need an application layer gateway for that.
- 4,021
1
vote
Why IPv6 neighbor solicitation uses multicast instead of unicast address?
Ethernet, while everywhere, is not the only layer 2 technology.
Scrolling through "IPv6 Packets over" RFCs will reveal diverse link layers including Bluetooth low energy ITU-T G.9959 ...
- 31k
1
vote
Accepted
DHCPCD does not delegate an assigned IPv6 prefix
Old thread, but this is one of the few hits Google spits out in 2022 for configuring IPv6 PD with isc-dhcp-client, so for what it's worth:
there is a known limitation in earlier versions of isc-dhcp-...
- 26
1
vote
Accepted
IPv6 dynamic DNS client for Cloudflare
Since I didn't find a suitable solution, I implemented a simple tool for that exact purpose. It is unsurprisingly named cloudflare-dynamic-dns.
It selects a first IPv6 address assigned to the ...
- 131
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