Questions tagged [ipv6]

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

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4
votes
1answer
96 views

OSPF - networks/links don't get advertised

In my Multiarea-OSPF configuration I can ping my neighbor, but nobody which is more than one hop away (for instance ABR2). Also traceroute just shows "1 * * * - 2 * * * - 3 * * *" Can ...
3
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2answers
1k views

OSPFv3 (newer commands) not working in Cisco Packet Tracer

The command router ospfv3 1 is not working in the Cisco Packet Tracer (Router: 2811). Does it work somehow or are the IOS version just not up-to-date?
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2answers
1k views

OSPFv3 - Sample configuration (Dual Stack IPv4 and IPv6) - Cheat Sheet

When configuring OSPFv2 on a router, you type in router ospf 10 router-id 1.1.1.1 network 10.0.0.0 0.0.0.3 area 0 for example. That way the network can be advertised per LSAs. But in OSPFv3 it ...
10
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1answer
2k views

Does IP provide QoS or not?

IP provides a best-effort delivery service. I believe this implies, among other things, that it offers no QoS to the users. However, IP has a byte in its headers (ToS in v4 and Trafic Class in v6) ...
3
votes
1answer
2k views

Is there any difference between Link-local and Site-local scope in IPv6 world?

What is the difference between Node-Local-Scope, Site-Local-Scope and Link-Local-Scope ? What does it mean Link local (link only) ? Is it only for a Subnet ? Why do we need site-local address then ?...
10
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4answers
2k views

Using IP subnet at multiple datacenters

We control IPv4 and IPv6 subnets. Now we'd like to use a part of a /24 IPv4 subnet at one datacenter and another part at another datacenter. I know that announcing the subnet on the internet at ...
1
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1answer
69 views

Can we use prefix address as the host address in ipv6?

IPv6 I read somewhere that we can use the first and last ip address as host addresses in ipv6. Is it true?
0
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2answers
2k views

Do we need different VLANs on IPv6 network? [closed]

With IPv6 there's new train of thought around this technology than IPv4. Since this protocol does away with broadcasts, is creating different VLANs necessary? Some people will argue that you can apply ...
2
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1answer
115 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 ...
7
votes
1answer
9k views

What is the use of the IPv6 scope ID?

In the structure struct sockaddr_in6, the field sin6_scope_id is declared. What is the use of this member? How can we know from the IPv6 address and the prefix length the scope that it should use?
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2answers
290 views

Why subnetting is implemented if we can use Network Address Translation (NAT)

As in subnetting a block of IP adresses are allocated, which leads to consumption of those IP addresses. Then how come we don't use Network Address Translation (NAT) as it will only need one IP ...
3
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2answers
6k 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 ...
1
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1answer
44 views

How to know which IPv6 interface will be chosen by the router?

I would like to know how does the kernel decide through which interface it sends data to some IPv6 address, how is the calculation done based on the routing table information: destination, gateway and ...
1
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1answer
123 views

Unsecured devices and IPv6

I'm currently starting to read up on IPv6, and as soon as I heared that every device can/will have a public accessible adreess i got a little freaked out. There are a lot of horror stories about ...
1
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2answers
452 views

IPv6 link local address unicity on a routed network

Going through an exercise from the CCNA practice exam I encountered an example that required the configuration of link local addresses on all interfaces. On Router 1 all interfaces were set to FE80::...
0
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2answers
369 views

Connect old device to IPv6

Hi I'm not an expert on networks and that's the reason why I'm posting this. My problem is that I have an old device (mediacenter box) that does not supports IPv6 to connect to Internet. Until now, ...
-2
votes
1answer
229 views

What is rdt_rcv(rcvpkt)/Λ in the given figure?

Please explain. I marked it in a red circle. It's rounded in red color.I got this from the book Computer networking a top down approach.Pg NUM 241. Section 3.4 Rdt 3.0
0
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1answer
671 views

Basic IPv6 Static Routing (Global Unicast Routing)

I have a topology like this: Every PC and router is configured with IPv6 addresses. -PING from PC1 to R1 is OK -PING from PC2 to R2 is OK -PING from PC3 to R3 is OK -PING from PC4 to R4 is OK ...
1
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1answer
60 views

Automatically determining ipv6 prefix size to blacklist? [closed]

When writing blacklist automation for my network, is there a way to automatically determine the prefix size of the other party?
1
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1answer
166 views

How can IPv6 host know default router's IPv6 address using RA?

I know an IPv6 host will send Router Solicitation (RS) messages, and a router on the link will reply Router Advertisement (RA) messages. In the RA message, there is the Source Link-Layer Address and ...
14
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3answers
2k views

Where can I use the IPv6 documentation prefix

We are currently building a networking course with a practical part where students have to configure a small network in a virtual environment. However, we are not sure what ipv6 prefixes we can use ...
72
votes
5answers
31k views

Is “IPv10” a joke or a serious RFC draft?

Internet Protocol version 10 (IPv10) Specification The name is funny (IPv4 + IPv6 == IPv10), but the actual proposal looks strange (one more packet format to battle incompatibility between packet ...
0
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1answer
52 views

Authentication header doubt

In a book by Forouzan (https://www.amazon.com/Data-Communications-Networking-McGraw-Hill-Forouzan/dp/0072967757) I've read that the sequence number of the authentication header doesn't get repeated ...
1
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1answer
700 views

IPv4 and IPv6 gateway subnet differences

I understand why for IPv4 the host and the gateway should be part of the same subnet, but for IPv6 I am a little bit confused. There are several types of IPv6 address assignment, but IPv6 requires the ...
2
votes
1answer
966 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 ...
1
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1answer
114 views

How to block outside initiated traffic in NPTv6?

NPTv6 does prefix translation between one IPv6 address to another. Is there a way to prevent outside initiated traffic to inside (preferably in A10 AX devices)?
1
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1answer
400 views

IPv4 to IPv6 one-to-one mapping for a whole Class A range

Are there any IPv6 technologies that support translating one-to-one mapping from IPv4 to IPv6 for the whole Class A range, like 10.0.0.0/8 network to a particular IPv6/40 range? Preferably for A10 AX ...
1
vote
1answer
244 views

Cisco 3560G not passing IPv6 RA when VLAN without IPv6 address

Problem: When having VLAN without IPv6 address on L3 enabled switch, no RA is passed through VLAN unless there is IPv6 address assigned to the VLAN. Static assigments however are reachable fine. ...
1
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3answers
3k views

My first IPv6 ping fails

I have some dual stack websites. When I open my websites they connect using IPv4 the first time, and then IPv6. If I ping the IP address directly, the first ping fails for IPv6 and then works fine. ...
1
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2answers
420 views

Do NDP and Link Local addresses remove the need for a router to have multiple routable IP addresses?

I'm trying to get my head round IPv6. I've stumbled on something which surprised me, and I'm looking to understand this better in terms of networking: Do Link Local addresses remove the need for a ...
1
vote
1answer
426 views

IPv6 default route

The IPv4 default route in CIDR notation is 0.0.0.0/0 translated to IP: 0.0.0.0 mask: 0.0.0.0 For IPv6 the default route in CIDR is ::/0. How is this transated ? Is it as below ? IP: :: mask: ::
1
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1answer
129 views

Doubt on handling mutable fields in IP header when computing digest or authentication data

I read RFC 4302, IP Authentication Header, Section 3.3.3, Integrity Check Value Calculation. In page 13, it is mentioned that the fields which are mutable during transit, like TTL or hop count, are ...
1
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1answer
612 views

Max hosts of subnet IPv6

When a interface takes an IPv6 address it does the DAD mechanism. A NS will be sent to the multicast address "solicited node multicast group address". If there is another interface in this multicast ...
1
vote
1answer
560 views

How to configure a VLAN for all its client to get stateful IPv6 through a DHCPv6 server in the network on a Cisco C891F router?

Alright, so I've been trying this without any luck the whole day. How to configure a VLAN for all its client to get stateful IPv6 through a DHCPv6 server in the network on a Cisco C891F router? My ...
3
votes
1answer
769 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 ...
1
vote
4answers
184 views

IS-IS IPv6 over IPv4

In IS-IS the router knows the interfaces addresses of the other routers. So would it be possible to connect two IPv6 areas over an IPv4 area? A router in area A knows that the destination ipv6 ...
9
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1answer
1k views

What happens when a subnet reaches capacity?

Other than not being able to claim any more IP addresses in a subnet, what other bad things happen when a subnet reaches 100% utilization, if anything?
0
votes
1answer
78 views

Would two hosts with arbitrary IPs communicate with /0 mask in the same subnet? [closed]

I'm studying for my networking finals and this thought experiment crossed my mind. I was told that as long as two hosts are in the same subnet they can communicate by using only ARP requests skipping ...
1
vote
3answers
159 views

How would I make a client find a server with an unknown IPv6 Address?

Let me first explain my situation: I am currently in the process of trying to build a solution for managing multiple Internet of Things devices on a network. It should be possible to automatically ...
3
votes
2answers
192 views

Are IP source and destination fields necessary on LAN?

When sending a packet from one computer to another over LAN, you send both an ethernet header and an IP header. The ethernet header has a source and designation MAC address, and the IP header has ...
4
votes
2answers
8k views

How does computer in IPv4 network communicate with computer in IPv6 network

I have a Verizon cell modem that uses IPv6 addressing only. I can use it to access IPv4 addresses, like browsing the Internet. However, if I try to ping this IPv6 address on a cell modem from IPv4 ...
1
vote
2answers
1k views

SLAAC : What's wrong with this generated IPv6 address?

Consider this MAC : a4:ba:db:fe:b24b. The method "SLAAC" allows us to generate an IPv6 from this MAC: First we put fffe in the fourth and fifth bytes Then, we invert the 7th bit of the first byte. ...
1
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2answers
341 views

How do I determine the IPV6 address added to VXLAN when interface is set to up? [closed]

Setup: Currently working on a machine with Red Hat 7.2 (Red Hat Enterprise Linux Server release 7.2 (Maipo) to be exact.) I have a vxlan interface configured: # ip link add test.123 type vxlan dev ...
2
votes
1answer
361 views

assigning ULA and global adresses simultaneously

For my internal Network, i'd like to set up IPv6 with ULAs assigned with DHCPv6, a bit like with IPv4s RFC1918 private addresses: I'm independent from the Prefix of my ISP for the internal networking ...
2
votes
1answer
596 views

IPv6 ULA vs. Global addresses for private (intra entity) peering

I am working on converting my core to IPv6. My current addressing scheme includes the VLAN in the IPv6 address: VLAN1511: XXXX:XXXX:XXXX:1511::1/64 However I have some VLAN overlap (the same VLAN ...
1
vote
1answer
224 views

Using IPv6 for multihome ISP eBGP peering due to IPv4 public /24s no longer available

Problem: I have two routers, and two separate ISPs (two different public ASNs). I wish to accept full BGP routes in order for us to properly set up true reliable ISP failover in a way that allows ...
2
votes
2answers
258 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 ...
6
votes
1answer
6k views

Method for assigning IPv6 ULA addresses to LAN

I'm finally embarking on the voyage that is IPv6. I am not sure however, on the best way of assigning a unique local address (ULA) to each host in my LAN. For IPv4 I prefer to have a DHCP server ...
2
votes
1answer
104 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
votes
1answer
179 views

Difference in convergence time IPv4 vs IPv6

Using protocols like RIP, OSPF and EIGRP, would IPv6 converge faster in smaller network like 4 routers? Would it differ in bigger networks?

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