Questions tagged [ipv6]

For questions about Internet Protocol version 6 (IPv6); as specified in RFC 8200.

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4
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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 ...
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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 ...
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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?
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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'...
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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
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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
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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
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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
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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 ...
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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
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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 ...
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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 ...
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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
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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 ...
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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
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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
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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
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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
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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
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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
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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
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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 ...
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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?
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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 ...
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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
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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 ...
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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 ...
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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 ...
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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?
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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
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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. ...
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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....
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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
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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
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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
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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
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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 ...
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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
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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
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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 ...
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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
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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
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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
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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
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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
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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
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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
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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 ...

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