Questions tagged [icmpv6]

Internet Control Message Protocol version 6 (ICMPv6) is the implementation of the Internet Control Message Protocol (ICMP) for Internet Protocol version 6 (IPv6). ICMPv6 is defined in RFC 4443. ICMPv6 is an integral part of IPv6 and performs error reporting and diagnostic functions (e.g., ping).

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SendEcho ERROR: sending to ICMPv6 packet to [2a06:98c1:3121::7]: (101) Network is unreachable

we are using (Ubuntu 20.04 / Squid server / running on Azure) we are getting bellow error, SendEcho ERROR: sending to ICMPv6 packet to [2a06:98c1:3121::7]: (101) Network is unreachable We are not ...
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Can safely block these ICMPv6 message types on a web server?

I have a Debian 11 VPS on a cloud provider, with both IPv4 and IPv6 enabled and the eth0 interface with both a global-scoped ipv6 address (public) and a link-scoped ipv6 address (fe80::/10). The sole ...
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Netflow records with Destination Ports 1025,257 and Protocol as ipv6-icmp

I have some Netflow records from a bunch of routers. The records contain IPv6 flows and there are entries with protocol as ipv6-icmp and their destination port values as 0, 1025 and 257. I know from ...
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Force IPv6 NS source to be global instead of link

In summary, how can I force an interface to use the global IPv6 address as the source for neighbor solicitation messages rather than the link address? Background: Many VPS providers do not allocate a ...
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No Router Advertisement from router after sending Router Solicitation from Linux

Have a Debian 10 Linux and ZTE ZXR10 5960 L3 switch as a router on the network. The problem is that Linux send Router Solicitation (RS) packet without "Source link-layer address" as ICMPv6 ...
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How to nicely make a neighbors discovery solicitation on Linux?

I am looking for a way to retrieve the MAC address of a specific host on a LAN network. I know its IPv6 address. Ideally I would like a way to trigger the Linux Kernel to perform the neighbor ...
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Difference between icmp and icmpv6 for ip6tables?

I found the following lines in a firewall script on one of our Linux servers (kernel 5.x) ip6tables -A INPUT -p icmp -j ACCEPT ip6tables -A INPUT -p ipv6-icmp -j ACCEPT The two commands both run ...
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Almost empty pf.conf still logs packets

I have an issue that my pf logs many packets that it's not supposed to log. I reproduced it with almost empty pf.conf: set skip on lo and it still logs some packets. I think that all those packets ...
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Dynamic router advertising on IPv6

I have a problem that I'm hoping I can solve with IPv6 but since I haven't had a chance to try it yet I thought I'd propose my solution here. My problem is that we have a LAN with a number of devices ...
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Multiple routes from router advertisements

Consider the following simplified setup: All devices are IPv6 enabled. Interfaces are configured in a way that we have 3 networks as shown. Router advertisments are enabled on both routers R1 & ...
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Can I filter based on a ICMPv6 subtype?

I'm trying to filter out specific ICMPv6 packets and I tried looking at all the possible types options by using the following command: ip6tables -p icmpv6 -h This yields the following types (note ...
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ICMPv6 restrictive firewall: losing connectivity over time

The problem: Losing IPv6 connectivity to a remote IP after certain time period without establishing a connection to the remote IP. My setup: I'm running a server with ip6tables firewall that filters ...
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Is it common for DHCPv6 and RA to provide IPv6 addr in the same subnet?

For IPv6, both DHCP and RA (the "prefix information" option, with the A flag) can provide IPv6 addresses to hosts. I'm still confused if it's common for DHCPv6 and RA to provide IP addresses in the ...
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How to trigger IPv6 router solicitation on bridge slave port entering RUNNING state?

I have a small Linux system that runs a bridge br0 between its wired eth0 and wireless (AP mode) wlan0 network interfaces. For br0 I have enabled IPv6 (stateless) autoconfiguration; this is actually ...
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Disable ICMPv6 Destination Unreachable replies

iptables -I OUTPUT -p icmp --icmp-type destination-unreachable -j DROP The above command works for IPv4, what should be the command for IPv6 to drop the ICMPv6 destination-unreachable packets. I have ...
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IPv6 - Allow incoming ICMP echo requests

So, we recently got our /48 prefix from our LIR, and started small-scale deploying it in a lab. What struck me as odd is that sites like http://ipv6-test.com/ insist that you allow incoming ICMP Echo ...
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Linux host does not retransmit with a lower packet size in response to ICMPv6 Packet Too Big message

I'm seeing this in Wireshark when curling this URL: On the same network, a Windows host retransmits properly, but an Android host does not. On a different network (presumably appropriately configured)...
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IPv6 dead before receiving ICMPv6 ping

TCPv6 and UPDv6 are dead until server received ICMPv6 ping. Further analysis shows that actually TCP and UDP packets won't even come to the server. But after receiving ICMPv6 ping, everything starts ...
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How to ping a host with different MTU size to simulate icmpv6 packet too big scenario?

As the Title states,I want to check whether my host will actually send a ICMPv6 packet too big if i send a packet with beyond the defined MTU size.I don't have a cisco router(extended ping) to try out ...
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Debian Wheezy doesn't answer to ICMPv6 neighbor solicitations

Hello, there. I manage some Wheezy servers with IPv6 enabled on all of them. They all have a global IPv6 /64 block using the first address in the block as the primary, i.e.: root@Host /h/david# ...
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IPv6 PPP Link fails forwarding Router Advertisements into local LAN

A Debian Server having eth0, eth1. eth2, ppp0 devices: 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether xx:yy:zz:yy:xx:yy brd ff:ff:ff:ff:...
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IPv6 radvd with vlans

Is it possible to configure the radvd config so that the router advertisement packets got a VLAN- tag? Theres a switch between my Router (software router, Ubuntu OS) and I only want some VLANs to ...
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Worldwide IP Latency [closed]

I want to create a simulation of the protocol MIPv6 (http://www.ietf.org/rfc/rfc3775.txt), for this reason I need information about latency, jitter and round-trip time. My first guess is install ...
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Multicast Listener Report Message v2

I run an ICMPv6 protocol and I have made a capture using wireshark. In the capture I have some Multicast Listener Report Message v2. Some of the has the source ip, the ipv6 link local address, but ...
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Advertise a subnet route with radvd

we have set up a small IPv6 Testing network. The setup looks like this: ::/0 +----------+ | Firewall | Router to the public net +----------+ | 2001:...::/106 | +---------...
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IPv6 connect B to A works, A to B fails with B's SYN-ACK receiving ICMP destination unreachable prohibited

I'm testing on IPv6. A is a server in a Cogent colo with native IPv6, call it 2001:db8:1111::1. B is a Mac mini behind an Airport Extreme router behind ISP Comcast; the router is set up to use ...
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2 votes
2 answers
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Filtering IPv6 ICMPv6 messages

So I'm playing around with IPv6 on my home network a bit more, and I'm doing things a bit old-fashioned -- setting up static addresses and such. This means I don't really want or care for all the ...
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3 votes
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IPv6, multiple routers and possible bad prefix advertisement in ICMPv6 RA

I have two 'router' type devices setup on my network. One is my actual IPv6 router - a Cisco 2621 (fe80::xxxx:3e60). It's the correct default router. Another is a DLINK DIR-615 (fe80::xxxx:5760). It'...
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