Questions tagged [ipv6]
For questions about Internet Protocol version 6 (IPv6); as specified in RFC 8200.
381
questions
0
votes
0answers
25 views
Distance Command in OSPFv3
Does anyone know if there is a way to specify the distance of a specific neighbor in OSPFv3 in a Cisco router/switch? You seem to be able to do it for an entire area, but not for a specific neighbor ...
1
vote
0answers
43 views
Why is an IPv6 interface required to have a link-local address?
According to Link-local address on Wikipedia:
In IPv4, link-local addresses are normally only used when no external, stateful mechanism of address configuration exists, such as the Dynamic Host ...
0
votes
1answer
56 views
Extra IPv6 Addresses - where are they coming from? [closed]
I recently got assigned a block of IPv6 addresses by my ISP. I've set it up with prefix delegation and it works just fine. When I plug a NIC in on the network it quickly picks up an IPv4 address from ...
0
votes
2answers
51 views
IPV6 static Routing
I'm new to networking and I'm currently learning about IPv6 in static routing. I set up an environment in Cisco Packet Tracer like this: have connected two routers with serial medium , each router ...
2
votes
2answers
81 views
What Does a Private IPV6 address look Like?
I'm doing a presentation on how the internet works, and I'm wondering if there is even such a thing as a private IPV6 address. If so, what does a private IPV6 address looks like?
1
vote
1answer
80 views
What is the last usable address in an IPv6 network
IPv6 does not have broadcast, so is the last address usable? Besides it being long, is it bad practice to actually use it?
For example: A:B:C:D::0/64 starts with A:B:C:D:0000:0000:0000:0000 and ends ...
0
votes
2answers
35 views
IPv6 Extension Headers and UDP/TCP/ICMPv6 Checksums
Should the checksum for IPv6 packets (UDP, TCP, ICMPv6, etc.) change if extension headers are present? For example, will a UDP packet without a Hop-By-Hop extension header have a different checksum ...
0
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0answers
38 views
IPv6 - link-locals mess
I am implementing IPv6 in my network and for now I have my own routable IPv6 /48 block, Cisco routers, Cisco switches, OSPF between them and several hosts. Its all working fine, but there is something ...
24
votes
3answers
6k views
Will IPv6 make private IP addresses become obsolete?
Will it still be useful to make use of private IP addresses with IPv6?
0
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0answers
17 views
ipv6 connectivity and ESx
what does it mean of "Verify that the network infrastructure provides IPv6 connectivity for the ESXi hosts, vCenter Server and external database if used" ?
to install ipv6-only ESx environment, what ...
1
vote
0answers
27 views
If a server has both IPv4 and IPv6 addresses, how does the DNS determine which to return? See the following example [closed]
These Pings were done at different times of the same day:
C:\Users\LPress>ping www.ucla.edu
Pinging gateway.lb.it.ucla.edu [164.67.228.152] with 32 bytes of data:
C:\Users\LPress>ping www.ucla.edu
...
1
vote
1answer
48 views
IPv6 SLAAC and Static DAD
I started learning about IPv6 and I wonder what happens when you mix SLAAC and static addresses in the same /64.
My current understanding is as follows:
Machine A with a statically configured ...
1
vote
1answer
29 views
ipv6: I can ping only 1 interface within same network even with static route
This is how I set up a static route.
R1(conf): ipv6 route 2004:DB8:2233:23::/64 2001:DB8:1122:12::2
With this, I can ping to 2004:DB8:2233:23::2 (S2/2 on R2) but not to 2004:DB8:2233:23::3 (S2/2 on ...
1
vote
2answers
142 views
Can link local addresses be used for transit networks without breaking routability?
I am asking this because my ISP uses SLAAC/DHCPv6 to assign addresses to clients. Firewalls, no matter what brand/name/type get a link local IPv6 address complete with a link local gateway AND clients ...
1
vote
1answer
61 views
How Many Extension Headers Can an IPv6 Packet Have?
How many next-header extensions can an IPv6 packet contain?
I read here that it can contains:
None, one, or more.
which isn't very informative.
Below is a reference to an IPv6 packet I'm looking ...
2
votes
2answers
143 views
DAD and link local address
I'm a new guy in IPV6, and now I encounter a question, when ipv6 policy is Auto configuration, is it necessary to DAD on Link local address?
my question is, since link local address is created from ...
2
votes
1answer
63 views
How can MLDv2 work according to the RFCs 3810 and 4606?
When IPv6 Stateless Address Autoconfiguration is happening, an interface/node has to join the all-nodes multicast address and the solicited-node multicast address AFTER forming a "tentative" ...
0
votes
0answers
57 views
OPNsense and IPv6
I've got two servers hosted at online.net. They give away 1 free /48 subnet per user and configure them using DUIDs.
I'm using OPNsense as an VM (in combination with Proxmox) on each server to handle ...
13
votes
4answers
3k views
Difference between :: and ::1
I am confused about following netstat output. There are two kind of local ports.
The first is:
[::]8100
The second is:
[::1]8100
I know that [::1] is a loopback address for IPv6. My question is:
...
2
votes
1answer
58 views
When is the source address of ICMPv6 message types 133, 135 and 136 other than unspecified(::/128) or link-local(fe80::/10)?
According to rfc4861 the source address for Router Solicitation(ICMPv6 type 133), Neighbor Solicitation(ICMPv6 type 135) and Neighbor Advertisement(ICMPv6 type 136) can be an address assigned to the ...
32
votes
3answers
7k views
Why does the IPv6 header not include a checksum?
It is stated in Wikipedia that
an IPv6 header does not include a checksum.
What are the reasons that were behind this decision?
4
votes
0answers
56 views
PVLANs/Port isolation in IPv6 networks
We're currently using port isolation to prevent communication between computers on the same vlan and use client isolation on our guest wifi. The reason for having this enabled is to prevent unwanted ...
0
votes
0answers
10 views
Ipv6 link-local/multicast issue [duplicate]
When you ping a link-local address why is the destination (in packet tracer) to the solicited-node multicast address of the host and not the (FE80) link local address ? I understand that it needs to ...
0
votes
1answer
62 views
Is there a method to modify bits in IP packets with OpenFlow?
We've already known that ovs-ofctl provides many actions to modify packets like set_field, load, move...
but I can't find a suitable action or action combination to modify a bit in the IP packet ...
0
votes
1answer
68 views
Remotely Connecting an IPv6 Computer to a IPv6 Private Web Server
I have a private web server at my office, and I want to access that server remotely at my house via IPv6.
My office has both IPv4 and IPv6 enabled, but my home has only IPv6.
IPv4 works, but I have ...
0
votes
0answers
11 views
Why is the source / destination address ordering in IPv4 and IPv6 headers opposite of Ethernet source and destination MAC addresses? [duplicate]
Engineers always do things for a reason.
I've noticed that in Ethernet frames, the ordering is destination MAC address first, and then the source MAC address.
What's the reason for reversing the ...
1
vote
1answer
50 views
Next Header field in IPv6 vs Protocol field in IPv4, any difference?
So I am new to the IPv6 concept, and I seen that the Protocol field seems to be replaced with Next Header, and I have a question.
Question:
Is Next Header a complete replace of Protocol, or is they ...
2
votes
4answers
97 views
Why not put unicast address in IPv6 packet containing NDP neighbor solicitation instead of solicited-node multicast address?
This is a follow-up question to Why is the NDP Neighbor Solicitation message sent to the solicited-node address?.
Summary: say I would send an IPv6 packet and put the unicast address of the host I ...
0
votes
1answer
191 views
Fortigate and ipv6 routing
I have a Fortigate router and my ISP support ipv6. I'm getting a public ipv6 on the Fortigate and also on the computers on the lan (2a02:a18:9041....)
I have not to much understanding of ipv6, but by ...
2
votes
1answer
88 views
Confusion about IANA “Protocol Numbers” registery
In the IANA registery for "Protocol Numbers", there listed 2 IP protocol versions: IPv4 at #4 and IPv6 at #41. Their "protocol" column says IPv[46] Encapsulation, and "reference" column points to 2 ...
0
votes
1answer
30 views
Does network layer provide connection oriented service
I know that in TCP/IP model the data link layer provides connection less service.
While reading IPv6 Header. 'The flow label is used for connection oriented servie'.
How does TCP/IP model provide ...
4
votes
1answer
57 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 ...
3
votes
2answers
122 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
1answer
213 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
3k 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
82 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
65 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
58 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
194 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
29 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
98 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
54 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
23 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
3answers
290 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
70 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
52 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
58 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
257 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
29 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 ...
