{"id":49,"date":"2008-05-12T05:07:57","date_gmt":"2008-05-12T10:07:57","guid":{"rendered":"http:\/\/yourlinuxguy.com\/?p=49"},"modified":"2008-05-23T20:36:23","modified_gmt":"2008-05-24T01:36:23","slug":"how-can-i-disable-ipv6-on-an-existing-suse-system","status":"publish","type":"post","link":"https:\/\/yourLinuxGuy.com\/?p=49","title":{"rendered":"How can I disable IPv6 on an existing Suse system?"},"content":{"rendered":"

Please, I beg you, don’t get into a philosophical debate with me about why IPv6 is enabled by default on many OSes today, and why I should not disable it, and the future of IP, and so on, and so on… We’ll save that abstract aspect for a future post… Now, back to the point…<\/em><\/p>\n

I always disable IPv6 when I am installing a new Suse server (in the initial setup dialogs).<\/p>\n

Sometimes, however, I come across a system (customers, etc) that was installed with IPv6 enabled, and now I need to disable it. Not a big deal. I’ll get to that below, but first some background…<\/p>\n

I want to point out that there are a few main aspects to “running” IPv6; a couple of them on the local system in question, and then one on the remote systems:<\/p>\n

    \n
  1. Many utilities and clients that run on Linux (like Firefox, apache daemon, etc.) utilize IPv6 — if available — on the local host in some fashion, and many of these can have the IPv6 turned off (like Firefox network.dns.disableIPv6<\/span><\/code> set to “Yes” in “about:config”)…<\/li>\n
  2. The kernel now has IPv6 enabled by default, but can easily be disabled (see below), effectively disabling IPv6 for all utilities and clients, and…<\/li>\n
  3. Remote DNS servers (or any server for that matter) likely<\/em> will not respond to your IPv6 DNS queries and requests anyway, so there is no real reason for you to have IPv6 enabled on *your* end… Unless, of course, your organization has made a mass decision to move to IPv6 completely (or at least mostly).<\/li>\n<\/ol>\n

    So, to disable IPv6 at the kernel level (on most Suse systems, though it’s basically the same on others), do the following:<\/p>\n

    vi \/etc\/modprobe.conf<\/span><\/code><\/p>\n

    …and change\/set<\/em> the following:<\/p>\n

    alias net-pf-10 off<\/span><\/code><\/p>\n

    Next, …<\/p>\n

    vi \/etc\/modprobe.conf.include<\/span><\/code> (or modprobe.conf.local<\/span><\/code>)<\/p>\n

    …and add<\/em> the following:<\/p>\n

    alias ipv6 off<\/span><\/code><\/p>\n

    …and reboot to complete the change. That’s all!<\/p>\n

    Now, in theory, your system will be a “faster” client (or a faster server), even though the slowness was really no fault of its own in the first place….<\/p>\n

    Of course, it might be a good idea to go through any applications that were enabled to use IPv6 and modify them to only use IPv4. For instance, for Postfix, change\/set the following values in \/etc\/postfix\/main.cf<\/span><\/code>:<\/p>\n

    inet_protocols = ipv4<\/span><\/code><\/p>\n

    ….instead of all<\/span><\/code>, and…<\/p>\n

    inet_interfaces = 127.0.0.1<\/span><\/code><\/p>\n

    …notice the lack of the IPv6 loopback address, “::1<\/span><\/code>“.<\/p>\n

    Enjoy!
    \n\ud83d\ude42<\/p>\n","protected":false},"excerpt":{"rendered":"

    Please, I beg you, don’t get into a philosophical debate with me about why IPv6 is enabled by default on many OSes today, and why I should not disable it, and the future of IP, and so on, and so…
    Read more<\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[12,13,15],"tags":[],"class_list":["post-49","post","type-post","status-publish","format-standard","hentry","category-advanced","category-oeslinux","category-suse"],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pnjn1-N","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=\/wp\/v2\/posts\/49","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=49"}],"version-history":[{"count":0,"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=\/wp\/v2\/posts\/49\/revisions"}],"wp:attachment":[{"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=49"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=49"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yourLinuxGuy.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=49"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}