Questions tagged [icmpv6]
For questions about ICMP version 6 for IPv6, where ICMPv6 is defined in RFC 4443. It is an integral part of IPv6 and performs error reporting and diagnostic functions (e.g., ping), and has a framework for extensions to implement future changes.
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Why is ICMP placed in transport layer in 6TSCH protocol stack?
my whole college education I was sure that ICMP protocol is a Network Layer protocol. I am now working with 6TSCH protocol and it's stack contains ICMPv6 in a Transport Layer, for example in this RFC: ...
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Actually ICMP message makes layer3 reliable?
We know that ICMP is connectionless because it does not require hosts to handshake before establishing a connection.
But when packets gets dropped in between route then respective router informs the ...
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Is an ICMPv6 neighbor advertisement meaningful if no options are set?
This is what I think a normal ICMPv6 neighbor advertisement should look like:
It says "I'm 2001:57a:d000::54 and you can reach me at 02:02:53:85:21:25". This is what neighbor advertisements ...
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Calculating Checksum for ICMPv6 Packet
I have a packet that has a checksum of 0xffff, and a calculated checksum of 0x0000. I know in UDP, a checksum of 0x0000 is not allowed, and is instead replaced with 0xffff, thus the packet should be ...
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How is ICMP Packet Too Big handled in IPv6?
I am trying to comprehend the way packets fragmentation works in IPv6.
As far as I understand it, IPv6 routers never fragment packets: upon receiving a packet whose size is bigger than the MTU of the ...
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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, ...
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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 ...
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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 ...
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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 ...
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How does router advertisement in IPv6 avoid IP conflict?
If a router advertisement sends the range of subnet, and the client can choose an IP from it, how is there no conflict with another client that has chosen the same address?
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Network flooded with ICMPv6 Multicast Listener Report Packets
I recently noticed that 3 out of 4 Unifi APs kept reaching 100% CPU usage. When I jumped onto the networks and took a Wireshark capture I noticed 1000s of these packets being sent in just a matter of ...
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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 ...
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Enabling Multicast Listener Discovery (MLD)
Do standard NICs that support IPv6 have the ability to perform MLD?
Essentially I understand MLD, but am struggling to find if it needs to be configured or if it is enabled by default on a host. Just ...
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Force ICMPV6 packet using envelope icon
I play with Packet Tracer 6.2 using IPv4 and IPv6 addresses, trying to ping routers using the envelope icon.
When both routers are IPv4 or IPv6, clicking envelope correctly chooses between ICMP and ...
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Calculating checksum for ICMPv6
Referring http://www.faqs.org/rfcs/rfc1071.html, I try to deduce the c code for calculating the checksum for ICMPv6. But check with the checksum parse by wireshark, I find that the answer got from my ...
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Is it ok if multiple non-router devices send IPv6 RAs with same prefix in the same network?
We engineer embedded systems (electronics & software), running our own OS with LWIP (a network stack). The device is configured to be IPv6 only (means: no IPv4 is available). These embedded ...
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IPv6 Neighbor Discovery procedure with a ping example [closed]
Given the following capture (click to zoom):
There are 3 routers attached to a switch. One of them pings FF02::1 (packet #2). I understand, that the other two routers have to figure out the first ...
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router advertisement packet
Networking beginner here, trying to understand the output of the tcpdump tool using a captured router advertisement packet.
tcpdump -i wlp4s0 -nn -t -c1 -vvv -X -s0
Based on what I've found online, ...
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IPV6 Neighbor Advertisement (NA) not recieved
I'm trying to make a project to detect NAs in an inter-vlan IPv6 environment via trunk line. I know that NAs are sent in multicast so it would be possible to see the NA messages using a trunk line. ...
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MLD messages during IPv6 duplicate address detection
I was wondering if anyone can shed some light on when Multicast Listener Discovery (MLD) messages ought to be send during IPv6 Duplicate Address Detection. RFC4862 section 5.4.2 gives a detailed ...
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Entirely wireless network being taken down by ICMPv6 neighbor solicitations
We are in our second week of school, now, and starting yesterday we started receiving complaints about slow wireless internet. After some investigating, we found out that our entire wireless network ...
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Why do some common traceroute implementations default to using UDP probes?
I was recently troubleshooting a network connectivity meta-problem, in that I knew a given destination was reachable, but I was not able to demonstrate that with traceroute because the path went cold ...
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IPv6 replacement for ICMP timestamp
Does any standard IPv6 protocol has anything analogous to an ICMP timestamp message?
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Is TCP maximum segment size (MSS) "clamping" compatible with IPv6?
With IPv4, TCP MSS "clamping" (a network device editing the MSS value in a TCP header) can help when path maximum transmission unit discovery is not working. (e.g., when ICMP is being blocked ...
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