Questions tagged [ipv6]
For questions about Internet Protocol version 6 (IPv6); as specified in RFC 8200.
404
questions
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
votes
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?
1
vote
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
votes
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
votes
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
vote
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
votes
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
votes
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?
1
vote
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
votes
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
vote
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
vote
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
vote
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
votes
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
votes
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
vote
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
vote
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
votes
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
votes
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
vote
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
vote
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
vote
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
vote
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
vote
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
vote
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
vote
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
votes
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
vote
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?
