Questions tagged [ipv6]

For questions about Internet Protocol version 6 (IPv6); as specified in RFC2460.

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8
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2answers
5k views

Is it true that the fd00::/8 address range (ULA) in ipv6 is for machines that you NEVER want to speak with anything on the Internet?

Is it true that the fd00::/8 address space (User Local Addresses) in ipv6 is for machines that you NEVER want to speak with anything on the Internet? I was just reading that here and rather surprised ...
2
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3answers
65 views

Do extension headers in IPv6 increase the header length

I was reading about IPv6. It says the header is of a fixed size i.e. 40 bytes, then how come is it able to accommodate extension headers. Doesn't this alter the size of headers. Please help, cant ...
1
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3answers
89 views

How to do subnetting on IPV6 for non nibble boundaries?

As I was reading this article on How to: calculating IPv6 subnets outside the nibble boundary https://blog.apnic.net/2018/08/10/how-to-calculating-ipv6-subnets-outside-the-nibble-boundary/ The author ...
2
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2answers
4k views

pfSense IPv6 NAT

I know many of you said that IPv6 has no NAT, but my server provider told me, that it is possible. I have no idea how... I have a pfSense Server as my Firewall (Not the router!). I have a /28 IPv4 ...
0
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0answers
10 views

Cannot ping IPv6 tap interface on Linux machine from Windows 7/10 [closed]

I have a raspberry pi than is running 6lbr (an 6LoWPAN/RPL Border Router) which create a tap interface bridged with eth0 through br0 as follow: br0 Link encap:Ethernet HWaddr 02:0a:0b:0c:0d:0e ...
0
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0answers
17 views

What is meant by “IP fragmentation is done on a 8-byte boundary”? [duplicate]

I was learning about IPv4 fragmentation and came across the follwoing line: The data of the long packet is then divided into two portions on a 8 byte (64 bit) boundary, so that the first packet ...
5
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1answer
168 views

What does NAT64 do which can't be done by deploying IPv6 + NAT444?

Why was NAT64 developed? What does it do that can't be done by deploying IPv6 + NAT444, and allocating your customers a (public) IPv6 and a (private) IPv4 address (behind a shared public IPv4 address)?...
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0answers
22 views

How to route dynamic PPPoE prefix delegated IPv6 prefixes to a layer 3 switch on IOS XE

Network setup: IOS XE 16.x --> Cisco 3560G layer 3 switch --> clients The IOS XE device does PPPoE dialing to our ISP and runs some VPNs to other sites. The 3560G does inter-VLAN routing and ...
0
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1answer
24 views

How to assign an ipv6 address to router 2900 gigabitethernet 0/0/0 - 0/0/3 interfaces?

I am working with a cisco router model 2900 which has four gigabitethernet 0/0/0 - 0/0/3. They do accept ipv4 addresses, however they will not accept ipv6 address. I have tried to use svi (assigning ...
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3answers
52 views

Can u explain this representation of the IPv6 address 1001::1 64?

::1 is for loopback address. An IPv6 address contains 8 16-bit pieces. What do this representation 1001::1 64 mean (what is the full address with all 8 16-bit pieces)?
0
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1answer
38 views

Packet Tracer 7.2.1 does not support eigrp for ipv6

I'm trying to enable eigrp for ipv6 in packet tracer but is seems to only have ospf and rip for ipv6. Is this a recent limitation?
1
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0answers
18 views

Can a Neighbor Advertisement response packet trigger the transition from STALE to DELAY?

I think the title is pretty descriptive. I cannot seem to find anything in the standard about what kind of packets could trigger the transition from the state STALE to the state DELAY, in the ...
1
vote
1answer
45 views

How much of an IPv6 address should be considered a single “identity” when counting votes [closed]

I'm building a web platform that uses upvotes and downvotes on each piece of content to bring good content to the top. It's important that it's non-trivial for this voting to be rigged, and previously ...
0
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1answer
50 views

Ping error ipv6

I am able to ping a PC1 to R1, Pc2 to r2 and PC3 to R3. All routers can ping each other. PC's can also ping themselves but I can't ping different PC's, I also cannot ping a PC to their own Gateway. ...
1
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1answer
38 views

Remote Host Neighbor Cache Entry State after Neighbor Solicitation request

When a Host A sends for the first time a NS request to another Host B, host B answers with a NA. In Host A Neighbor Cache, the state Entry for host B gets from INCOMPLETE to REACHABLE, when NA comes ...
1
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1answer
34 views

Assign a new public and static IP to a router behind my main router [closed]

What can you suggest to bring a second public and static IPv4 so I can configure my WAN-A interfase with my primary and an additional secondary IP settings so I can route all the traffic from the ...
5
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2answers
42k views

Stateful vs Stateless IPv6?

What's the difference here? Are stateful IPv6 entries retained in the DHCPv6 server?
11
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4answers
8k views

Why is the U/L bit inversed in EUI64?

This inversion is bijective, so I can't figure out what is it's use.
0
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1answer
39 views

RDP on IPV6 using DS-Lite-Tunnel [closed]

I am trying to access one of my PCs from and external network using RDP on port 3389. After realizing my ISP uses DS-Lite-Tunnel I gave up ipv4 and focusing on ipv6. So far the only way I managed ...
1
vote
1answer
20 views

How to group 3 hosts in ACE Ipv6 statement

I know for ipv6 ACE there is no wildcard mask, so if I want to add three hosts in one statement, for example, which prefix should I use for that network? (network 2001:db8:cafe:1/64, ::1 reserved as ...
8
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6answers
4k views

Could IPv6 make NAT / port numbers redundant?

From what I can tell, each process could get its own IP address, with loads of IP's to spare. What would the drawbacks be? Essentially, your host would become a router and each process is a host (in ...
2
votes
1answer
77 views

Setting Destination MAC address for RTP/UDP packets

I have a requirement where I have to send the UDP packet to a destination multicast IPv6 address. In addition to that the packets must also have corresponding destination multicast MAC address set. I ...
4
votes
3answers
2k views

Usage of Flow label in IPv6 header?

I have been reading the IPv6 Flow Label Specification (RFC 6437) and I would like to ask about the purpose of setting this label. In case of just using the 2-tuple (source address, destination ...
21
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4answers
8k views

What is the proper term for ipaddress/hostname:port

What is the proper term for (example) hostname.tld:433 (hostname:portnumber)? It is not just hostname, and it is not really a URL either :) same goes for 10.0.0.1:3306 etc.
1
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1answer
59 views

Does CSR1000v on AWS support IPv6?

I'm trying to implement Segment Routing IPv6 (SRv6) in Cisco CSR1000v on AWS. I'm having issues with IPv6 which gave the impression that IPv6 data plane does not work. Similarly, I configured a ...
3
votes
1answer
42 views

How to handle IPv6 Extension Header Options with action = 01

RFC 8200 section 4.2 states that if a node does not recognize an option type, that node must do some action depending on the 2 higher order bits of the option type. When the higher order bits are 01, ...
2
votes
2answers
56 views

How to handle ICMP-in-IPv6 or ICMPv6-in-IPv4?

Since ICMP and ICMPv6 have different IP protocol numbers, it's technically possible for an IPv4 host to receive an ICMPv6 packet or for an IPv6 host to receive an ICMP packet. Is the host's behavior ...
6
votes
1answer
71 views

How to set IPv6 RA values for RDNSS and DNSSL on HPE/Aruba 5400R

I am detail-planning the roll out of IPv6 in our company. Right now I am stuck with IPv6 RA on our HPE/Aruba Access Switches. I cannot find any documentation how to set the Recursive DNS Server (RDNSS)...
2
votes
1answer
32 views

ipv6 dhcp pool option link-address

I'm learning to set up an ipv6 dhcp pool in Packet Tracer. And I'm stomped on what a link-address is as an option in a dhcp server ipv6. I've read this https://www.cisco.com/c/en/us/td/docs/ios-xml/...
5
votes
2answers
164 views

How to architect a globally distributed website, from an IP address perspective

I would like to have a website that is loaded fast from any point in the world. From my understanding, you need to take advantage of the data center "regions" at places like Google Cloud or AWS. That'...
2
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0answers
50 views

RPL: questions on routing mechanism

I'm studying RPL and two questions came to my mind: 1: Both in storing and non-storing modes, if a node wants to send a packet to another node via P2P communication paradigm, then how does the ...
16
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4answers
14k views

IPv6: Why not use /126 on P2P links for IPv6?

In IPv4 we use /30 to conserve addresses. So why do some people recommend using /64 on P2P links instead of /126? I get using a /64 on regular subnets but isn't using a /64 when there will only ever ...
4
votes
1answer
212 views

IPv6 default route not being installed from RA

Platform: Juniper SRX300 Version: JUNOS 15.1X49-D160.2 ISP: Midco I currently have an issue where the IPv6 default route is not being installed from the CMTS RA. Try as I might, I cannot get ...
5
votes
2answers
771 views

Does IPv6 have similar concept of network mask?

Does IPv6 have similar concept of network mask? How does it represent a network? In the output of ifconfig, does prefixlen 128 represent a network mask? lo: flags=73<UP,LOOPBACK,RUNNING> mtu ...
7
votes
2answers
974 views

Why do IPv6 unique local addresses have to have a /48 prefix?

According to RFC 4193, unique local addresses will always have a prefix of FD00::/8.. but according to Wikipedia: The block fd00::/8 is defined for /48 prefixes, formed by setting the forty least-...
12
votes
3answers
1k views

Are the IPv6 address space and IPv4 address space completely disjoint?

Tanenbaum's Computer Networks says Finally, IPv4 addresses can be written as a pair of colons and an old dotted decimal number, for example: ::192.31.20.46 Does it mean the IPv4 address space ...
2
votes
1answer
47 views

What can an IP address be assigned to?

What can an IP address be assigned to? A network interface, which is what I thought originally. (I seem to hear a network interface can have multiple IP addresses assigned to it, and if it is true, ...
5
votes
3answers
569 views

address-family ipv6 on Cisco 3560G

Is anyone aware of an IOS version for the C3560G that supports configuring a neighbor to exchange IPv6 routes? Apparently 12.2(37)SE Advanced IP Services can't do it - as soon as you try to activate ...
3
votes
1answer
110 views

IPv6 Wireshark filter for partial IP address

I would like to create a display filter with the last 4 octets of an IPv6 address. Basically, I have the mac address with me and I want to filter for the IP address xxxx:xxxx:xxxx:xxxx:113:5005:80:...
0
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0answers
105 views

Mininet - Configure an IPv6 Router

There are a handful of examples for adding an IPv4 Router in a mininet topology. What there are almost no examples of, is how to add an IPv6 Router in a topology. I have read a few posts on the ...
2
votes
2answers
93 views

How are IPv6 addresses grouped? [closed]

I apologise off the bat if this question is too basic to belong in this group. Perhaps it can be moved elsewhere if that's the case, or I can be directed to another SE site. With IPv4 I have long ...
2
votes
1answer
47 views

IPv4 only host on a dual stack environment

I am looking into migrating to IPv6 at my company. Our plan is to dual-stack everything for now, however, we have a couple of local servers that are IPv4 capable only. The rest of our network will be ...
3
votes
1answer
29 views

How to convert size represented in one prefix length to another?

Example, let's say if someone says, I have allocated one /64 address. How can I convert that to a size in /30? How many /30 equals to one /64?
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3answers
2k views

IPv4 & IPv6 IPSec differences

I am an undergraduate student where I decided to develop a firmware that would eliminate the security vulnerabilities that exist within the current technologies used. such as tunneling, translation ...
2
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4answers
2k views

Dual Stack Network Configuration

I am trying to implement Dual Stack configuration of a network in Packet Tracer. I have two routers connected to each other both of these routers have one IPv4 client and one IPv6 client. The routers ...
0
votes
2answers
65 views

Security implications of IPv6 tunneling over IPv4

I've read that IPv6 over IPv4 tunnels are a security risk because IPv6 traffic cannot be intercepted by Intrusion Detection Systems and Firewalls. This apparently deterred some networks to deploy IPv6....
2
votes
0answers
52 views

DHCP ivp6 vs DHCP ipv4 router config (cisco)

When setting up a router as dchp server in ipv4, we specify a pool under which we give the network and the default-gateway and that's it: However in ipv6 stateless dhcp , we create the pool then ...
2
votes
1answer
40 views

Where is the block which caused IPV4 client can not access IPV6 Server

I read many documents which are saying if you are in IPV4 network then you can not access IPV6 network, for example when I was at home I can not access some IPV6 website, such as:ipv6test.google.com. ...
4
votes
2answers
510 views

Configure Juniper Router Advertisements

I am currently setting up IPv6 on my network ran by a SRX-240H2 as router. Besides others the router as an internal interface configured as follows: [edit interfaces ge-0/0/4 unit 802] clb@srx01-av# ...
7
votes
1answer
8k views

Mitigating a IPv6 malformed packet multicast flood

So we just had our first IPv6 multicast flood in the network this morning. We managed to stop the offending computer by blocking the mac address with: mac-address-table static x.x.x vlan x drop ...