Questions tagged [ipv6]
For questions about Internet Protocol version 6 (IPv6); as specified in RFC 8200.
404
questions
4
votes
2answers
3k views
Host IPv6-only website and allow access to IPv4-only clients
Lets say site.example.com runs only with AAAA records, and I wish to access that site from IPv4-only network, and I don't want to do tunneling neither other protocols that masquerades IPv4 over IPv6 ...
0
votes
1answer
827 views
High traffic caused by DHCPv6 [closed]
We have a medium sized network setup with multiple switches and one firewall (pfsense).
We now have IPv6 since two months and sometimes can observe, that there is a huge amount of traffic on the ...
8
votes
1answer
1k views
What is the meaning of streamlined ipv6 header?
I don't understand what it is meant for "streamlined ipv6 header"?
Could you please provide an example?
2
votes
1answer
109 views
Why does Neighbor Discovery Protocol have to monitor upper-layer protocols?
While reading the RFC of NDP I wondered, why it is necessary to monitor upper layer traffic in order to know if a neighbor is reachable, e.g. a TCP ACK.
I do get the IPv6 packet anyway, so I know it'...
8
votes
4answers
4k views
Does IPv6 remove the need for a VPN?
I know that a VPN may be used in lots of different ways for lots of different things, so I'm not suggesting that IPv6 removes the need for a VPN completely.
I'm interested in one particular use-case:
...
1
vote
2answers
610 views
How does data encapsulation work in the TCP/IP stack?
As a UDP segment traverses down the stack, each layer adds a header.
What occurs for this to happen? Does the kernel do a bunch stuff then add the header?
I am particularly interested in the ...
1
vote
1answer
70 views
Misbehaving host always uses the gw's MAC as destination: Violation of standard?
We have an appliance that always uses the IPv6 gateway's MAC address as the link layer destination address for all its outgoing IPv6 packets, even when the receivers IPv6 address is on the same subnet....
1
vote
1answer
911 views
How does address resolution work with multicast, specifically IPv6?
If I want to send an IPv6 UDP multicast message, how does L3 to L2 address resolution occur?
I think I understand ARP and how this same idea applies to unicast, but I am struggling to grasp the idea ...
1
vote
1answer
291 views
VRRP VRID configuration for IPv6
Can we use same VRID (VRRP instance) for both IPv4 and IPv6 virtual router in VRRP or VRRP-E?
In a layer-3 router, we have requirement to configure interface VE with both IPv4 and IPv6 gateways with ...
9
votes
2answers
3k views
What are common sizes to split a /29 - /32 IPv6 subnet?
As an LIR, you are getting a /29 to /32 network allocation by the RIPE, but I am a bit overwhelmed by the size of this subnet, and don't find a starting point to split this into common sizes.
What we ...
5
votes
1answer
796 views
IPv6 Link-local addresses
RFC 4291 specifies that IPv6 link-local unicast addresses must have a high-order bit sequence of 1111111010, or fe80::/10. However, the same document specifies that the 54 bits following the first 10 ...
1
vote
1answer
146 views
Is Path MTU Protocol more beneficial for IPv6
Should Path MTU Discovery (PMTUD) be implemented over fragmentation regardless of whether it is IPv4 or IPv6? Or should it just be implemented in ipv6 due to fragmentation now being handled through ...
2
votes
1answer
79 views
Multhoming including incoming connections?
I am investingating the option of connecting our business network to 2 separate ISPs for redundancy.
Since we have a couple of B2B services which need to be accessible from outside, in order to have ...
1
vote
1answer
400 views
Enabling Multicast Listener Discovery (MLD)
Do standard NICs that support IPv6 have the ability to perform MLD?
Essentially I understand MLD, but am struggling to find if it needs to be configured or if it is enabled by default on a host. Just ...
1
vote
2answers
2k views
How does the TCP/IP stack handle UDP checksum errors?
RFC 2460, Internet Protocol, Version 6 (IPv6) Specification, Section 8.1 Upper-Layer Checksums, states the UDP checksum is mandatory and any IPv6 receivers must discard UDP packets containing a zero ...
2
votes
1answer
3k views
Why the FF:FE in EUI-64?
EUI-64 IPv6 addresses are generated from MAC addresses by taking the network prefix (64 bits) and appending the first half of the MAC address, then FF:FE, then the second half of the MAC. Is there a ...
4
votes
2answers
1k views
Why are IPv6 addresses so long?
By convention, each device on the LAN under IPv6 gets a /64 subnet, right? That's an obscene number of addresses per device! Why not make the addresses shorter, say, 72 bits, then each device would ...
2
votes
1answer
549 views
MAC Spoofing and EUI-64
I have two questions that both assume an attacker who has my MAC address:
Suppose an attacker connects to the Internet before me, spoofing my MAC. I then connect and tell people to connect to my EUI-...
2
votes
2answers
4k views
IPSec in IPv4 and IPv6
I'm getting a little confused in understanding the differences in IPSec in IPv4 and IPv6...
Are the principles of IPsec the same in v6, but instead of it being optional it is now mandatory for it to ...
5
votes
2answers
2k views
IPv6 and online privacy and security
I am studying up on IPv6 and part of the talk was about how the machines generate or can have multiple IPv6 addresses for internal use and external use.
Does this mean that there is no longer a "...
1
vote
1answer
8k views
Start with 192.168.67.0/24 and split it into 4 equal networks, what is the third usable IP address of the 3rd subnet? how do you solve this? [duplicate]
Start with 192.168.67.0/24 and split it into 4 equal networks, what is the third usable IP address of the 3rd subnet? how do you solve this?
0
votes
1answer
211 views
Openvpn and IPV6: how to configure it without knowing the server's IPV6 address
I'm using openvpn to connect to a network through a VPN and I use a ovpn file which is the following:
dev tap
persist-tun
persist-key
cipher AES-128-CBC
auth SHA1
tls-client
client
resolv-retry ...
1
vote
2answers
834 views
Subnet and routing on IPv6
I would like to know:
1) What is the smallest routable subnet size in IPv6 ?
2) Can a /128 address be routed in a IPv6 network?
13
votes
3answers
4k views
Should a router use SLAAC for IPv6 address assignment?
I am a little confused by the following 2 RFCs relating to IPv6:
RFC 4862 (IPv6 Stateless Address Autoconfiguration)
RFC 7084 (IPv6 CE Router Requirements)
RFC 4862 states:
The autoconfiguration ...
0
votes
2answers
2k views
How to split an IPV6 nibble? [closed]
I've been tasked with assigning IPV6 addresses to be split into data centers in several different cities, in several different countries in several different continents. Part of the instructions is to ...
4
votes
2answers
11k views
What does a switch do when the destination MAC address is unknown?
Say I just connected my computer to the internet through a home/office LAN network. I then proceed to ping google.com. Of course, the DNS converts google.com to the destination IP address, but how is ...
0
votes
1answer
52 views
IPv6 create many gateways
We want to implement ipv6 on our network as we begin to offer our customers dual stack.
We offer dedicated servers and we wish to give a /64 with each server.
In one vlan, we wish to have 255 x /64
...
1
vote
1answer
642 views
Juniper EX IPv6 outside LAN isn't working
JunOS version: 12.3R11.2
Juniper EX switch with 2 VLANs:
vlan 0: IPv4: 10.0.0.6/20
This vlan is used for private IP space
vlan 1: IPv4: X.X.X.254/24
IPv6: XXXX:XXXX:X:XXX::ffff/64
This vlan is ...
1
vote
1answer
2k views
IPv6 RA flags and various combinations
What flags are available in an IPv6 RA and how are their various combinations interpreted by Windows, Linux and BSD?
0
votes
2answers
751 views
Configure tunnel between IPv6 enabled server and local IPv4 network
I am newbie here and also for IPv6 network.
I have one debian installed server which is able to send IPv6 traffic.
Now in my local network, ISP not supporting IPv6 traffic. I want to configure tunnel ...
1
vote
1answer
100 views
Pinging computer on a different network
I would like to know if it is possible to ping a computer on a different network using ipv6. If I am understanding it correctly then IPV6 was created for each device to have its unique ip address. ...
1
vote
4answers
112 views
What is the common notation of multiple subnets
I store many IP-Addresses in a database. Is there any common notation for a group of IP-Addresses and subnet.
Currently I dither between these notations:
*.*.*.160/29
?.?.?.160/29
...160/29
x.x.x....
4
votes
1answer
1k views
IPv4 vs IPv6 performance
What are the differences in performance for IPv4 and IPv6? Is there much of a difference in speed? and what are some of the methods that could be used to test this?
3
votes
1answer
460 views
Finding Subnet Ranges of IPv6
I need to find a single subnet range to cover 10,000 IP addresses (hosts), given the IPv6 Address 2405:1300:c5c1:322::/108 (for example)
I am aware of how to do subnet in IPv4 but cannot grasp the ...
2
votes
2answers
175 views
IPv6 link-local only core network
When planning an IPv6 strategy is it possible to have link-local only addresses within the core transit network (sort of analogous to a BGP-free MPLS core)?
If not why not?
If yes are there any ...
1
vote
1answer
181 views
How do I generate ESP trafic (IPv6)?
I have this topology:
I only have moon and sun. After the connection was successfully established, I need to generate ESP packets for wireshark capture.
How do I generate ESP packets?
When I use ...
2
votes
2answers
408 views
Two IPv6 global unicast addresses on the same interface (stateless and stateful)
Can I assign two global unicast address to the same interface, one obtained via stateful addressing (DHCPv6) and the other one via SLAAC (eui-64)?
According to the RFC-4862:
Both stateless address ...
1
vote
0answers
101 views
Can I run IPV6 L3VPN over MP-BGP IPV6?
I am looking for information about how to implement IPV6 L3VPN over MP-BGP IPV6 but i can see only IPV6 L3VPN over MP-BGP IPV4 (dual stack).
When I implement ipv6 l3vpn over mp-bgp ipv4, I activate ...
2
votes
4answers
672 views
What prevents someone from obtaining and using a random public IP address?
I understand that IANA delegates public IP addresses to five Regional Internet Registries in which ISPs can purchase IPs from.
What is to stop someone not associated with IANA or any RIR from ...
2
votes
1answer
272 views
IPv6 - RA prefixes and flags
I'm trying to understand how SLAAC works, but having troubles understanding how the information inside the Router Advertisement is used by a client.
Let's say neither the Manager nor the Other ...
14
votes
4answers
1k views
Possible (bit) patterns of a netmask
Given a prefix Y, it's easy to calculate the corresponding netmask: Put Y times a set bit, and then fill up "to the right" with zeros until one has 32 bits (IPv4) in total.
Example:
Prefix 24, thus ...
0
votes
3answers
5k views
What is a valid public IP address?
What is a valid public IP address? When I was checking my ID to see if it was blacklisted, it came up with the above Amanda… "Please enter a valid public IP address,", so therefore my questions are:
...
1
vote
1answer
73 views
Would multiple RIPng processes improve convergence times and stability and larger RIP deployments
You could label this a theoretical question but I consider it a design question.
Is is possible to have a large RipNG deployment using multiple RINng instances and
simulate OSPF like areas?
Thanks
2
votes
3answers
12k views
Access Server ipv6 from a ipv4 only network
One of my Server is sitting behind a network which is only accessible trough a IPV6 (no double stack IPv4/IPV6 available).
How can I access the server (SSH, HTTP, other protocols) from an network ...
3
votes
1answer
524 views
Any router will automatically join at least two multicast groups on each interface. How do I see that on a Cisco router?
Any router will automatically join at least two multicast groups on each interface. How do I see that on a Cisco router?
I know that they all join these two groups: all multicast nodes and all ...
11
votes
2answers
14k views
Why don't we use MAC address instead of IP for having “Internet” or doing communication? [duplicate]
We know MAC address is unique in each devices.So why can't we just send/receive data using MAC address only?
1
vote
1answer
967 views
DNS64/NAT64 WiFi hotspot using Windows [closed]
Is there a way to have this option proposed by Apple available in Windows? I want to test connecting an IPv6-only client to an IPv4-only server on a local environment.
1
vote
1answer
80 views
How to get the IPv6 [closed]
I'm in a network that provides both IPv4 and IPv6 for the nodes, and i have the IPv4 of a machine. How can I find the IPv6 assigned for this machine?
1
vote
1answer
256 views
Checking split horizon status with IPv6
In a frame relay multipoint topology where the routers are running RIP, we know that RIP by default keeps split horizon on with IPv6 and we go into the RIP process an use no ip-split horizon to ...
3
votes
2answers
292 views
IPv6 tunneling over IPv4
I am willing to build a program that simulates the routing process of IPv6 packets over an IPv4 overlay network (tunnel). From what I have read so far I have understood that the IPv4 tunnel packets ...
