Questions tagged [ipv6]
For questions about Internet Protocol version 6 (IPv6); as specified in RFC2460.
356
questions
0
votes
1answer
13 views
Function of the P-bit flag in an IPv6 multicast
Currently I'm trying to learn (common) things about IPv6 and started with the address format and the address scopes. Finally I reached the multicast part where my problem with the definiton of the ...
1
vote
2answers
28 views
Is the first address in an IPv6 subnet assignable?
I am working in a lab and have configured a series of /125 subnets between routers. Lets ignore the best practice for this discussion of using /64 for everything.
When I assign fd00:f9a8:ffff::257 to ...
0
votes
0answers
9 views
IPv6 packets not being forwarded between two interfaces [on hold]
We have a VM that has a tunnel to HE for IPv6 on interface he-ipv6
There's a server LAN on ens256 and a tunnel to a different place on tun0.
Whenever we try to access a host on ens256 over IPv6, the ...
0
votes
0answers
19 views
pfsense DHCPv6 relay for LAN clients [on hold]
I am trying to get clients on the LAN side of my pfsense firewall to get IPv6 addresses from the DHCPv6 server on my cable modem.
The cable modem has an IPv6 address and all devices on the same ...
0
votes
0answers
17 views
In which system, what type of change they did to support IPv6? [on hold]
Currently, we are using IPv6 addresses to communicate on the internet. To support IPv6 where networking giants made changes.
0
votes
1answer
43 views
Understanding EUI-64
I was reading Forouzan's book. It says following:
In IPv4 addressing, there is not a specific relation between the hostid (at the IP level) and link-layer address (at the data-link layer) because ...
3
votes
2answers
2k views
Why the first octet of a MAC address always end with a binary 0?
I stumbled upon a piece of code on GitHub: https://github.com/adeverteuil/bash-ula-generator/blob/master/gen-ula.sh
# Generate an EUI64 from the MAC address
# as described in RFC 3513
# https://tools....
1
vote
2answers
63 views
Why is the IPv6 link-local address not /9?
According to this answer, it's because computers read addresses in binary.
Fine. That explains why the fe80 address does not need to be /12 or /16--it's because everything after the 10th bit is a ...
2
votes
1answer
60 views
configure IPv6 ACL on interface WS-C3750X-48
I am using WS-C3750X-48 model switch. license is lanbase. I have activated cmd on my switch:
sdm prefer dual-ipv4-and-ipv6 routing. Then i did reload. After that, i will able to config IPv6 on ...
0
votes
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 ...
0
votes
0answers
30 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 ...
5
votes
1answer
178 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)?...
0
votes
1answer
25 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 ...
-1
votes
3answers
60 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
votes
1answer
45 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
vote
0answers
19 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
46 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 ...
1
vote
3answers
137 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 ...
0
votes
1answer
54 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
vote
1answer
45 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
vote
1answer
38 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 ...
0
votes
1answer
53 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
23 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
votes
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
115 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 ...
1
vote
1answer
68 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
3answers
75 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 ...
2
votes
2answers
72 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 ...
2
votes
1answer
66 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
167 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
votes
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 ...
7
votes
2answers
1k 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-...
2
votes
1answer
51 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, ...
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 ...
5
votes
2answers
777 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 ...
4
votes
1answer
312 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 ...
3
votes
1answer
153 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:...
2
votes
1answer
56 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
30 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?
2
votes
2answers
97 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 ...
0
votes
2answers
76 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
1answer
44 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.
...
0
votes
0answers
160 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 ...
4
votes
1answer
457 views
Will the packet be dropped when the number of hops equals to default TTL?
From my understanding, the default TTL represents the maximum number of hops allowed such that the packet may reach the host.
NTP Documentation Archive: ttl - This option is used only with ...
2
votes
1answer
51 views
Can mobile devices take a global IPv6 address by means of only routing?
I'm probably asking this the wrong way, but here it is; I have a /48 block with static addresses for every device on the network. Everything is routed, no NAT, no tricks.
My question is: on a mobile ...
3
votes
1answer
45 views
Why aren't we encrypting data on Network level instead of transport level when using e.g. HTTP [closed]
Why we are bothering to encrypt our data on a transport level, instead of just doing that on a network level with e.g. IPSec and get rid of the need to to that in upper layers. For example instead of ...
0
votes
1answer
62 views
IPv6 variables or other methods of shortening
From the dawn of when I heard about IPv6 many years ago, to my continued hesitance to make good use of it in today's world where it's eventually going to become necessary... my biggest issue I think ...
1
vote
1answer
89 views
Which part of an IPv6 address is assigned by the RIR?
Given my PC or any other, which part of the IPv6 address is allocated by the RIR and which part is allocated by the ISP?
I know a prefix of /64 is commonly used, does that mean the bits before the /...
6
votes
4answers
829 views
OSI layer of Neighbor Discovery Protocol
NDP operates using ICMPv6 and, even though ICMPv6 messages are encapsulated in payload field of IPv6 datagram, ICMPv6 and ICMP are usually considered as network layer protocols. At least, on Wikipedia ...
