Questions tagged [ipv6]

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

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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, ...
3
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1answer
171 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:...
3
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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 ...
3
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1answer
3k views

Understanding the difference between EUI-64 and IPv6

I understand that Extended Unique Identifier (EUI-64) allows a host to automatically assign itself a 64-bit interface identifier IID for an IPv6 address. My question is: What is the purpose of using ...
3
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1answer
960 views

How to calculate the Subnet address?

I have an ipv6 address FC00::50, and the subnet mask length is 64. How to calculate an subnet address? I want address FC00::50 in the scope of this calculated subnet address. Here is the description: ...
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2answers
850 views

EX4200 / EX3300 IPv6 Routing Question

we have about 5 Servers and currently only a cheap L2 Switch. We got an /42 IPv6 Network assigned from our provider and want to route this /42 Network into multiple /64 subnets. These can just be ...
3
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1answer
62 views

Global Unicast in IPv6 Neighbor Discovery

I have a very small pcap file in which Neighbor Discovery is performed for Global Unicast Addresses. That is, IPv6 addresses of both neighbors as I can see in Wireshark start from 2001:. Both IPv6 ...
3
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1answer
76 views

Quagga router advertisement messages are wrong after an address change

I have a problem with Quagga OSPFv3 implementation. I have a Mininet topology with a host connected to a router. I assigned an IPv6 address to the router interface. And I enabled IPv6 ...
3
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1answer
671 views

NAT64 return translation doesn't work

I'm doing a NAT64 translation on cisco router. The translation from IPv6 to IPv4 work but the return isn't translated neighter in the NAT64 statistics. config: interface GigabitEthernet0/1 nat64 ...
3
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1answer
390 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 ...
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3answers
4k views

IPv6 addressing (slash notation)

I've recently been studying the fundamentals on IPv6, but there are some things that I don't quite understand about how the addressing is structured. I know that link local addresses start with FE80, ...
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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 ...
2
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2answers
327 views

If the IPv6 address will be strictly based on EUI-64 logic then is there any real need of Neighbour Discovery Protocol?

I am building my fundamentals on IPv6 and have realised the multicast group is nothing but FF02::1:FFXX:XXXX. Here xxx is nothing but 24-bits of Mac-address (48 bits) with simple 7th bit magic. ...
2
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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 ...
2
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1answer
279 views

How many ipv6 prefixes are currently in use?

Is there a good estimate to how many ipv6 prefixes are currently being used?
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3answers
77 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
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1answer
100 views

IPv6 address scheme for network gear

I'm looking for best practice advice on how to IPv6 address your internal infrastructure network gear (routers, switches, etc). In my searching I've seen some people suggest using /127 like in a /30 ...
2
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1answer
308 views

Does IPv6 Prefix Delegation work with SLAAC, without the need of a DHCPv6 server/client?

All the (cisco) documentation I found about this topic always uses a DHCPv6 server or client to configure Prefix Delegation. But I never read that this is a requirement. Can Prefix Delegation be ...
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2answers
193 views

How does/did an ISP serve so many people over IPv4

Whilst reading Tanenbaum - Computer Networks they talk about IP scarcity at the level of ISPs: IP addresses are scarce. An ISP might have a /16 address, giving it 65,534 usable host numbers. If it ...
2
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1answer
52 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, ...
2
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2answers
933 views

Man In The Middle on IPv6, are IPv4 packets affected?

If I successfully Man in the Middle attack an IPv6 Address of my victim can I also sniff its IPv4 packets? Attacks like Neighbor Advertisement Spoofing or Last Hop Router?
2
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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. ...
2
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1answer
63 views

IPV6 ping, the pinged address is different from the once caught by wireshark

I'm trying to ping an ECU, both PC and ECU have static IPV6 address the problem is that the target address (ECU) pinged is different from the one caught by Wireshark subnet : 64 ping command $ ...
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1answer
70 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 ...
2
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1answer
2k 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 ...
2
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2answers
151 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 ...
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2answers
975 views

IPv6 can't ping host when static route configured with exit interface

I have the following topology (using IPv6) interfaces: I have the following static routes configured on it: R1#sh ipv6 route static IPv6 Routing Table - default - 9 entries Codes: C - Connected, L -...
2
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1answer
290 views

IPv6 VPN addressing

I got two servers with public IPv4 and (now) IPv6 addresses. They have a VPN to do stuff like MySQL replication. With IPv4 I just took a RFC1918 range (10.0.0.0/8) and if you access the server via ...
2
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3answers
714 views

What is IP address management ? Why its needed ? How does the vendors like Bluecat Networks and Infoblox solves the IPAM problem? [closed]

Recently I heard a term IPAM i.e IP Address management. Theoretically I got the definition from Wikipedia, but couldn't understand its actual need. Since for that we have DHCP then What is the need ...
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2answers
80 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
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1answer
78 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/...
2
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1answer
58 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 ...
2
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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 ...
2
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1answer
238 views

Translation from unique local to global unicast address

is there NAT in IPv6 for private-to-public translation like in IPv4. I know that there is a protocol translation between v4 and v6 but did not find anything about same protocol translation . Thank ...
2
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1answer
407 views

What it means to configure two global ipv6 address on a single interface?

I have seen some network configuration files where a single interface is assigned with two different but similar ipv6 addresses, what is the significance of it, ex : interface te 0/1/0/10 ipv6 ...
2
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1answer
76 views

How does IPv6 AH guarranties authentication?

IPv6 Authentication Header uses MD5 hash on the payload, the header, and unchanging fields of the IPv6 header and options to prevent sequence quessing attacks. But all these required information to ...
2
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1answer
451 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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1answer
1k views

IPv6 Subnetting

I was making an IPv6 exercise in which I had to configure two Router Interface: G0/0 and G0/1 G0/0 uses 2001:DB8:FADE:00FF::/64 and I have to use to next subnet for G0/1 This is the answer, but What ...
2
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2answers
242 views

Are there limits to the number of global IPv6 multicast addresses in use at a time?

The address space for IPv6 multicast addresses is very large (something like 2^112) and so I'm imagining it might not be so hard to get my hands on a million or so of them at some point, and try using ...
2
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2answers
152 views

Broadcasts in IPv6

I'm aware of the fact that broadcast has been removed from IPv6 and just has multicast instead. However, recently I read "This process (ARP) is now achieved via a multicast address called the ...
2
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1answer
313 views

Why is only 24 bits of the MAC address used for multicasting?

When doing neighbor discovery in IPv6, the last 24 bits of the hosts MAC address is glued on to some link local multicast prefix. I'm wondering why 24 bits? Why not 48, or 32, or 16? What happens if ...
2
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1answer
748 views

Will home networks migrate to ipv6? [closed]

So I have a rudimentary understanding of working with basic networking tools, things like using nmap to scan ports and find IP addresses on internal networks, and ssh for connecting to various devices....
2
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1answer
649 views

IPv6 Testing Addressing Type Confusions

I'm new in the IPv6 Topic and Yesterday I was performing some testing on Cisco IOS and Cisco Routers of the addressing type in IPv6 with RIPng, i was testing the following: Global Unicast Address ...
2
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1answer
3k views

can pfsense perform ipv6 nat (for outbound service redirection)

I have to keep prefacing my question with "I am not trying to reimplement ipv4 nat inbound for outdated security I don't understand correctly". Hi! I am wondering if it is possible to implement an ...
2
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1answer
929 views

Generate list of IPv6 subnets on router using SNMP?

As a follow-up to Generate list of subnets on switch using SNMP?, we would like to do the same thing for IPv6 - i.e. poll all of our routers (Juniper and Cisco, at least for now) to identify which ...
2
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2answers
185 views

Are all the private IPv6 addresses nonoverlapping? If yes, is Route distinguisher required for IPv6?

I am wondering if all the private IPv6 address non overlapping. And if yes, I am wondering if RD is required for IPv6 addresses. When two customer sites of an ISP are using same overlapping private ...
2
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1answer
103 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'...
2
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2answers
375 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 ...
2
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1answer
245 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 ...
2
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1answer
80 views

Is IPv6 Routing Header useless?

RFC2460 doesn't describe any types other than Type 0. And in RFC5095, it deprecated Type 0 Routing Header. Does that mean Routing Header is useless?