| Message ID | alpine.LNX.2.00.0903180200590.10453@firda.kolla.no |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
Hello. In article <alpine.LNX.2.00.0903180200590.10453@firda.kolla.no> (at Wed, 18 Mar 2009 02:06:09 +0100 (CET)), Kolbjørn Barmen <linux@kolla.no> says: > > My personal oppinion is that anything ipv6 autoconfig/accept_ra should be > > default _off_, since this simplifies all the above mentioned issues, and > > it is incredibly easy to turn on again with systcl if people want it. > > It is much easier to enable ipv6 automagic than to disable it. > > At least there should be kernel/module parameter to set default behaviour. > > > > Part of the problem with deploying IPv6 is due to "magic" like this, all > > the autoconfig/router announcement magic looks very well on paper and in > > theory, but out in the field it quickly leads to loads of totally > > unnecessary extra work, work that could easily be avoided if default > > behaviour was to have it off. It should be in the interest of IPv6 > > advocates to support a "soft" transition from IPv4-only to dual-stack, > > fencing off unwanted "magic" only adds to the frustration for those who > > actually try to deploy it. > > > > What do you think? > > Obviously noone really think much of this, one way or the other, so here's a > patch that changes the default values. Default should be ON. But I would agree to have some (relatively easy) way to disable autoconfiguration. Well yes, probably kernel module papameter. Simple interface: - disable_ipv6=1 - autoconf=0 Do anyone need more complex interface? - disable_ipv6={all|IF}:0,... - autoconf={all|IF}:0,... --yoshfuji -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: YOSHIFUJI Hideaki <yoshfuji@st-paulia.net> Date: Wed, 18 Mar 2009 12:33:08 +0900 (JST) > In article <alpine.LNX.2.00.0903180200590.10453@firda.kolla.no> (at Wed, 18 Mar 2009 02:06:09 +0100 (CET)), Kolbjørn Barmen <linux@kolla.no> says: > > > > My personal oppinion is that anything ipv6 autoconfig/accept_ra should be > > > default _off_, since this simplifies all the above mentioned issues, and > > > it is incredibly easy to turn on again with systcl if people want it. > > > It is much easier to enable ipv6 automagic than to disable it. > > > At least there should be kernel/module parameter to set default behaviour. > > > > > > Part of the problem with deploying IPv6 is due to "magic" like this, all > > > the autoconfig/router announcement magic looks very well on paper and in > > > theory, but out in the field it quickly leads to loads of totally > > > unnecessary extra work, work that could easily be avoided if default > > > behaviour was to have it off. It should be in the interest of IPv6 > > > advocates to support a "soft" transition from IPv4-only to dual-stack, > > > fencing off unwanted "magic" only adds to the frustration for those who > > > actually try to deploy it. > > > > > > What do you think? > > > > Obviously noone really think much of this, one way or the other, so here's a > > patch that changes the default values. > > Default should be ON. I absolutely agree. It can't be called autoconfiguration if it's off by default, and you have to "configure" something. What are people smoking? :-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 19 Mar 2009, David Miller wrote: > From: YOSHIFUJI Hideaki <yoshfuji@st-paulia.net> > Date: Wed, 18 Mar 2009 12:33:08 +0900 (JST) > > > In article <alpine.LNX.2.00.0903180200590.10453@firda.kolla.no> (at > > Wed, 18 Mar 2009 02:06:09 +0100 (CET)), Kolbjørn Barmen > > <linux@kolla.no> says: > > > > > > My personal oppinion is that anything ipv6 autoconfig/accept_ra > > > > should be default _off_, since this simplifies all the above > > > > mentioned issues, and it is incredibly easy to turn on again with > > > > systcl if people want it. It is much easier to enable ipv6 > > > > automagic than to disable it. At least there should be > > > > kernel/module parameter to set default behaviour. > > > > > > > > Part of the problem with deploying IPv6 is due to "magic" like > > > > this, all the autoconfig/router announcement magic looks very well > > > > on paper and in theory, but out in the field it quickly leads to > > > > loads of totally unnecessary extra work, work that could easily be > > > > avoided if default behaviour was to have it off. It should be in > > > > the interest of IPv6 advocates to support a "soft" transition from > > > > IPv4-only to dual-stack, fencing off unwanted "magic" only adds to > > > > the frustration for those who actually try to deploy it. > > > > > > > > What do you think? > > > > > > Obviously noone really think much of this, one way or the other, so here's a > > > patch that changes the default values. > > > > Default should be ON. > > I absolutely agree. > > It can't be called autoconfiguration if it's off by default, and > you have to "configure" something. > > What are people smoking? :-) Reality? Anyways, I'm overthrilled to actually see response, since this has been pestering me (well, us), for years - configuring server with static addresses is a real _pain_ if machine is located on a network where autoconfigure and router announcements exist (or suddenly show up by error due to someone untentionally configuring their machine as router, some systems are even so clever that if they dont see router announcements, they will assume all sorts of things and start acting as 6to4 router themselves - YAY! NOT! People creating unintended network loops on the switch panel is another classic, leaving all machiens with double up of adresses and faulty default routes long after physical error has been fixed - woohoo! Sheesh, I could go on all day long about what a bad idea autoconf/accept_ra really is... :P ) I personally really dont care what is default as long as I have a _very easy_ way to turn it off, kernel module paramters and boot parameters - great! If the rest of the world has decided they want to fight this manually by default, fine by me :) How about the behaviour that I described: root:~# sysctl net.ipv6.conf.all.accept_ra net.ipv6.conf.all.accept_ra = 1 root:~# sysctl -w net.ipv6.conf.all.accept_ra=0 net.ipv6.conf.all.accept_ra = 0 root:~# sysctl net.ipv6.conf.eth0.accept_ra net.ipv6.conf.all.accept_ra = 1 Is this intended behaviour or not? Bug or (mis)feature? A few days ago I recieved mail from someone who was annoyed that even as he changed the values with sysctl and restarted the interface, the old addresses, routes etc were still up - yes, the lack of proper IPv6 support in distros "network interface up/down" scripts is really tedious, and there really is no easy way to "reset" ipv6 status on a machine, except from doing it manually. I dont see any distro care much for IPv6 anytime soon, so anything that can be done to ease IPv6 configuration is _very much appreciated_ for those of us who actually run IPv6 in full production. Cheers!
Kolbjørn Barmen wrote: > I personally really dont care what is default as long as I have a _very > easy_ way to turn it off, kernel module paramters and boot parameters - > great! If the rest of the world has decided they want to fight this > manually by default, fine by me :) I'll work on the module parameters Yoshifuji mentioned, the "harder" version since to me it seems more useful. Since it's of interest to you can you give me some input? Are the two parameters he described for this going to be good enough for you? I was thinking of also adding a "default" keyword to control net.ipv6.conf.default.*, for example: disable_ipv6=all,default,eth0,eth1 autoconf=all,default,eth2,eth3 This is because "default" is what's inherited by all the ethX values, "all" is the big hammer. And also adding an "enable_ipv6" one: enable_ipv6=lo,eth4,eth5 This would let you do: disable_ipv6=default enable_ipv6=lo,eth0 Which saves you from listing many interfaces: disable_ipv6=eth1,eth2,eth3,eth4.... Of course I could be over-thinking this and the simple solution could work just fine: disable_ipv6=1 autoconf=0 Then just let you put things in sysctl.conf to enable what you want. I'll play with that first to see if it's enough. I'd rather get this right the first time... > How about the behaviour that I described: > > root:~# sysctl net.ipv6.conf.all.accept_ra > net.ipv6.conf.all.accept_ra = 1 > root:~# sysctl -w net.ipv6.conf.all.accept_ra=0 > net.ipv6.conf.all.accept_ra = 0 > root:~# sysctl net.ipv6.conf.eth0.accept_ra > net.ipv6.conf.all.accept_ra = 1 > > Is this intended behaviour or not? Bug or (mis)feature? I *think* that's intended, at least it's one of the ways IPv6 differs from IPv4 - setting "all" doesn't reset to individual nic settings. But the code in ndisc_router_discovery() should probably check the "all" flag and drop the RA. The other "all" sysctl's should behave the same, so someone needs to take a deeper look. -Brian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 20 Mar 2009, Brian Haley wrote: > Kolbjørn Barmen wrote: > > I personally really dont care what is default as long as I have a _very > > easy_ way to turn it off, kernel module paramters and boot parameters - > > great! If the rest of the world has decided they want to fight this > > manually by default, fine by me :) > > I'll work on the module parameters Yoshifuji mentioned, the "harder" > version since to me it seems more useful. Since it's of interest to you > can you give me some input? Definetly! Thanks alot for the effort! :) > Are the two parameters he described for this going to be good enough for > you? I was thinking of also adding a "default" keyword to control > net.ipv6.conf.default.*, for example: > > disable_ipv6=all,default,eth0,eth1 > autoconf=all,default,eth2,eth3 > > This is because "default" is what's inherited by all the ethX values, > "all" is the big hammer. This is still unclear for me. I've been assuming that by changing "default" all future devices will inherit the value, but leaving existing devices as is. "all" I've assumed takes all existing interfaces, but leaving default as is. Is this what you are saying? > And also adding an "enable_ipv6" one: > > enable_ipv6=lo,eth4,eth5 > > This would let you do: > > disable_ipv6=default > enable_ipv6=lo,eth0 > > Which saves you from listing many interfaces: > > disable_ipv6=eth1,eth2,eth3,eth4.... > > Of course I could be over-thinking this and the simple solution could work just > fine: > > disable_ipv6=1 > autoconf=0 > > Then just let you put things in sysctl.conf to enable what you want. I'll play > with that first to see if it's enough. I think this would be enough yes. Probably best to think about how one would be able to set boot paramets so that a machine gets static address and no autoconf, for example for NFS-root etc. This falls under same "mission"? > I'd rather get this right the first time... Ofcourse :) > > How about the behaviour that I described: > > > > root:~# sysctl net.ipv6.conf.all.accept_ra > > net.ipv6.conf.all.accept_ra = 1 > > root:~# sysctl -w net.ipv6.conf.all.accept_ra=0 > > net.ipv6.conf.all.accept_ra = 0 > > root:~# sysctl net.ipv6.conf.eth0.accept_ra > > net.ipv6.conf.all.accept_ra = 1 > > > > Is this intended behaviour or not? Bug or (mis)feature? > > I *think* that's intended, at least it's one of the ways IPv6 differs from IPv4 > - setting "all" doesn't reset to individual nic settings. But the code in > ndisc_router_discovery() should probably check the "all" flag and drop the RA. > The other "all" sysctl's should behave the same, so someone needs to take a > deeper look. OK, I have this weird feeling that this "worked" some years ago, but I dont have any old systems to try out that theory on. I fail to see wht purpose "all" has, if it isn't setting the value of all interfaces. Again, thank you very much for looking into this! :) -- kolla -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Kolbjørn Barmen wrote: >> Are the two parameters he described for this going to be good enough for >> you? I was thinking of also adding a "default" keyword to control >> net.ipv6.conf.default.*, for example: >> >> disable_ipv6=all,default,eth0,eth1 >> autoconf=all,default,eth2,eth3 >> >> This is because "default" is what's inherited by all the ethX values, >> "all" is the big hammer. > > This is still unclear for me. I've been assuming that by changing > "default" all future devices will inherit the value, but leaving existing > devices as is. "all" I've assumed takes all existing interfaces, but > leaving default as is. Is this what you are saying? "default" is what's inherited by future devices, "all" is supposed to be the over-ride for all devices, but doesn't change any device-specific values. >> Of course I could be over-thinking this and the simple solution could work just >> fine: >> >> disable_ipv6=1 >> autoconf=0 >> >> Then just let you put things in sysctl.conf to enable what you want. I'll play >> with that first to see if it's enough. > > I think this would be enough yes. Probably best to think about how one > would be able to set boot paramets so that a machine gets static address > and no autoconf, for example for NFS-root etc. This falls under same > "mission"? My patch wouldn't address getting a static address via a module parameter, that can still be done in, for example, /etc/network/interfaces. So no, this isn't part of my "mission", just getting the basic functionality in place. >>> How about the behaviour that I described: >>> >>> root:~# sysctl net.ipv6.conf.all.accept_ra >>> net.ipv6.conf.all.accept_ra = 1 >>> root:~# sysctl -w net.ipv6.conf.all.accept_ra=0 >>> net.ipv6.conf.all.accept_ra = 0 >>> root:~# sysctl net.ipv6.conf.eth0.accept_ra >>> net.ipv6.conf.all.accept_ra = 1 >>> >>> Is this intended behaviour or not? Bug or (mis)feature? >> I *think* that's intended, at least it's one of the ways IPv6 differs from IPv4 >> - setting "all" doesn't reset to individual nic settings. But the code in >> ndisc_router_discovery() should probably check the "all" flag and drop the RA. >> The other "all" sysctl's should behave the same, so someone needs to take a >> deeper look. > > OK, I have this weird feeling that this "worked" some years ago, but I > dont have any old systems to try out that theory on. I fail to see wht > purpose "all" has, if it isn't setting the value of all interfaces. I fixed the autoconf one, but this would still need to be addressed in a future patch, trying to sneak-in before the deadline. Might be too late... I sent the actual patch to netdev a few minutes ago for review. -Brian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- linux/net/ipv6/addrconf.c.orig 2009-03-17 23:41:10.000000000 +0100 +++ linux/net/ipv6/addrconf.c 2009-03-17 23:42:18.000000000 +0100 @@ -157,9 +157,9 @@ .forwarding = 0, .hop_limit = IPV6_DEFAULT_HOPLIMIT, .mtu6 = IPV6_MIN_MTU, - .accept_ra = 1, + .accept_ra = 0, .accept_redirects = 1, - .autoconf = 1, + .autoconf = 0, .force_mld_version = 0, .dad_transmits = 1, .rtr_solicits = MAX_RTR_SOLICITATIONS, @@ -192,9 +192,9 @@ .forwarding = 0, .hop_limit = IPV6_DEFAULT_HOPLIMIT, .mtu6 = IPV6_MIN_MTU, - .accept_ra = 1, + .accept_ra = 0, .accept_redirects = 1, - .autoconf = 1, + .autoconf = 0, .dad_transmits = 1, .rtr_solicits = MAX_RTR_SOLICITATIONS, .rtr_solicit_interval = RTR_SOLICITATION_INTERVAL,