Arch Linux

frank419

Member

Registered: 2012-01-12

Posts: 33

Eth0 has multiple ipv6 add.?

Hey all,

Below is the output of ip add command on my arch box. I am getting erratic internet behavior. Why do I have so many addresses and how do I go about removing them / disabling IPV6?

Thanks

$ ip add
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 78:e7:d1:d6:ed:93 brd ff:ff:ff:ff:ff:ff
    inet 205.133.29.107/24 brd 205.133.29.255 scope global eth0
    inet6 2002:cd85:1d7f:c:5c8b:2c86:d56c:7f0c/64 scope global temporary deprecated dynamic 
       valid_lft 248589sec preferred_lft 0sec
    inet6 2002:cd85:1d7f:c:7ae7:d1ff:fed6:ed93/64 scope global dynamic 
       valid_lft 2254557sec preferred_lft 267357sec
    inet6 2002:cd85:1d66:c:5c8b:2c86:d56c:7f0c/64 scope global temporary deprecated dynamic 
       valid_lft 247527sec preferred_lft 0sec
    inet6 2002:cd85:1d69:c:5c8b:2c86:d56c:7f0c/64 scope global temporary deprecated dynamic 
       valid_lft 247019sec preferred_lft 0sec
    inet6 2002:cd85:1d66:c:c4d0:2f2b:9945:6ab8/64 scope global temporary deprecated dynamic 
       valid_lft 161730sec preferred_lft 0sec
    inet6 2002:cd85:1d66:c:7ae7:d1ff:fed6:ed93/64 scope global dynamic 
       valid_lft 2171210sec preferred_lft 184010sec
    inet6 2002:cd85:1d69:c:c4d0:2f2b:9945:6ab8/64 scope global temporary deprecated dynamic 
       valid_lft 161222sec preferred_lft 0sec
    inet6 2002:cd85:1d69:c:ca2:588d:d6b:39da/64 scope global temporary deprecated dynamic 
       valid_lft 75425sec preferred_lft 0sec
    inet6 2002:cd85:1d69:c:7ae7:d1ff:fed6:ed93/64 scope global dynamic 
       valid_lft 1997093sec preferred_lft 9893sec
    inet6 fec0::c:5c8b:2c86:d56c:7f0c/64 scope site temporary deprecated dynamic 
       valid_lft 247019sec preferred_lft 0sec
    inet6 fec0::c:c4d0:2f2b:9945:6ab8/64 scope site temporary deprecated dynamic 
       valid_lft 161222sec preferred_lft 0sec
    inet6 fec0::c:ca2:588d:d6b:39da/64 scope site temporary deprecated dynamic 
       valid_lft 75425sec preferred_lft 0sec
    inet6 fec0::c:7ae7:d1ff:fed6:ed93/64 scope site dynamic 
       valid_lft 2356148sec preferred_lft 368948sec
    inet6 fe80::7ae7:d1ff:fed6:ed93/64 scope link 
       valid_lft forever preferred_lft forever

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fukawi2

Ex-Administratorino

From: .vic.au

Registered: 2007-09-28

Posts: 6,237

Website

Re: Eth0 has multiple ipv6 add.?

Why do I have so many addresses

It's normal to have multiple IPv6 addresses, although not that many, and not duplicates.
Are Privacy Extensions enabled on your machine perhaps? https://home.regit.org/2011/04/ipv6-privacy/

and how do I go about removing them / disabling IPV6?

https://wiki.archlinux.org/index.php/IPv6#Disable_IPv6

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ghen

Member

From: Belgium

Registered: 2010-08-31

Posts: 124

Re: Eth0 has multiple ipv6 add.?

You have privacy extensions enabled, and the temporary IPv6 addresses you get have a relatively short preferred lifetime (hours) vs. a relatively long valid lifetime (weeks), hence the large number of "deprecated" addresses (still valid but no longer preferred for outgoing connections).  Privacy addresses are supposed to work that way, but maybe it's not what you want.

Rather than just disabling IPv6, it's a good opportunity to learn about it and start using it. :-)

fukawi2

Ex-Administratorino

From: .vic.au

Registered: 2007-09-28

Posts: 6,237

Website

Re: Eth0 has multiple ipv6 add.?

This seems to be the new default in Arch:

# grep use_tempaddr /etc/sysctl.conf
net.ipv6.conf.default.use_tempaddr = 2
net.ipv6.conf.all.use_tempaddr = 2

Annoying, but never the less.... To fix, change the above setting to suit you and reload using `sysctl -p /etc/sysctl.conf`

use_tempaddr - INTEGER
         Preference for Privacy Extensions (RFC3041).
           <= 0 : disable Privacy Extensions
           == 1 : enable Privacy Extensions, but prefer public
                  addresses over temporary addresses.
           >  1 : enable Privacy Extensions and prefer temporary
                  addresses over public addresses.
         Default:  0 (for most devices)
                  -1 (for point-to-point devices and loopback devices)

http://git.kernel.org/?p=linux/kernel/g … xt;hb=HEAD

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