How can I switch off IPv6 ND RA transmissions in Linux?

I am working on Ubuntu 11.04. I want to switch off the IPv6 ND RA transmissions. How can I do this?

Bruce

Posted 2011-11-05T23:03:31.340

Reputation: 2 067

I suspect that having answered the first part of your question you may want to edit this question so that the title more accurately reflects what you're looking for. – larsks – 2011-11-06T00:51:16.720

IPv6 ND has a whole list of functions associated with it. What specifically are you trying to disable?

– Mike Pennington – 2011-11-08T10:06:28.167

@Mike: I want to switch of Router Discovery – Bruce – 2011-11-09T03:54:05.920

Answers

You can turn off Router Advertisement acceptance via these sysctls:

net.ipv6.conf.default.accept_ra=0
net.ipv6.conf.all.accept_ra=0
net.ipv6.conf.eth0.accept_ra=0 (where eth0 can be any interface)

Beau

Posted 2011-11-05T23:03:31.340

Reputation: 188

It sounds like you don't want IPv6 enabled at all. If you don't have IPv6 ND, that's the equivalent of not having ARP in IPv4. So IPv6 will not be usable.

If you really want to disable IPv6 temporarily, issue the command:

sudo sysctl net.ipv6.conf.all.disable_ipv6=1

You could add this to a system startup file in order to disable it on each boot, or use your distribution's supported method to tweak sysctl variables. (On Ubuntu that would be creating a file in /etc/sysctl.d with the content net.ipv6.conf.all.disable_ipv6=1.)

If you want to disable other aspects of IPv6, run the command sysctl -a | grep ipv6 to see what options you have. You could, for example, disable the acceptance of DAD (duplicate address detection) packets, or the acceptance of RA (router advertisement) packets.

mpontillo

Posted 2011-11-05T23:03:31.340

Reputation: 931

You should disable radvd on the advertising machine. The configuration file is usually in /etc/radvd.conf

Mike Pennington

Posted 2011-11-05T23:03:31.340

Reputation: 2 273

What if the OP can't guarantee that all advertising routers have been removed from the network? (Someone might have set up a malicious "router" that tries to intercept IPv6 traffic, the router might not be under the OP's control, etc) – mpontillo – 2011-11-09T18:01:58.723

@Mike, wireshark is the standard tool to answer your question. My answer makes the assumption he is capable of tracing traffic back to the source. – Mike Pennington – 2011-11-09T18:22:51.740

By the way, here are some good tools (other than Wireshark, which will of course do the job) for troubleshooting ND in IPv6.

– mpontillo – 2011-11-09T18:51:04.170