On Dec 9, 2012, at 5:45 PM, Malcolm <malcolm_lewis@bellsouth.net> wrote:

Via YaST /etc/sysconfig editor and search on mtu and set as required.

That worked to set the MTU, but it still isn't grabbing the IPv6 address on boot. I don't know why. The MTU shows up as 1500 but I still have to kill the dhclient6 and restart it and then it grabs the IPv6 address. It doesn't seem to grab it on boot. Anybody else having this problem? Scott -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On 12/9/2012 6:16 PM, James Knott wrote:

Scott Simpson wrote:

...

I have my network card configured for IPv4 and IPv6 from my ISP. It isn't getting an IPv6 address. The daemons started are

/sbin/dhclient6 -6 -cf /var/lib/dhcp6/dhclient6.eth1.conf -lf /var/lib/dhcp6/dhclient6.eth1.lease -pf /var/run/dhclient6.eth1.pid -q eth1 /sbin/dhcpcd --netconfig -L -E -c /etc/sysconfig/network/scripts/dhcpcd-hook -t 0 -h madhatter eth1

for the IPv6 and IPv4 addresses respectively. When I reboot, my ethernet card has an MTU of 576 which isn't large enough to process an IPv6 address. If I bring down dhclient6, do an

ip link set eth1 mtu 1500

and then rerun dhclient6 then it grabs an IPv6 address and assigns it to the interface correctly. How can I change this MTU so I don't have to manually do this? Scott

You can set the MTU in Yast > Network Settings. Edit the details for the NIC. MTU is set on the General tab. With the MTU set to 1500 you should find IPv4 performance improves too.

Any clues on why this would be set to anything other than 1500? That seems pretty standard. Why would the op find his set at 576? -- _____________________________________ ---This space for rent--- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Cristian Rodríguez wrote:

as dhcpv6 does not seem to have MTU option to push (http://www.iana.org/assignments/dhcpv6-parameters/dhcpv6-parameters.xml ) it is either a bug in the configuration of his computer or the ISP is sending MTU RA advertising with that value..however in that case there is a major bug around because minimum ipv6 MTU is 1280. :-O

I suspect it's something with IPv4 that's setting the MTU and IPv6 has to use whatever it's set to. Normally, IPv6 doesn't use DHCP to obtain an address, as there are other methods of setting it. DHCP6 is used for other info such as routers, DNS servers etc. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

claims that dhcpcd is doing the dirty work. If that is the case and it is broken, 12.2 should use dhclient (not dhcpcd) for IPv4 when selecting ifup/ifdown (through YaST). My Linux box is a router and DNS server with my custom firewall rules so it needs the dhclient6 functionality. I haven't experienced that problem, as I don't use any DHCP for IPv6. However, I did experience another issue on my firewall port that's connected to my cable modem. If it uses DHCP, IPv6 is disabled entirely. I don't even get a link local address. I get IPv6 on that

Scott Simpson wrote: port, if I use static configuration. This is on openSUSE 11.4. I'll have to experiment to see if that fix you provided affects that. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

John Andersen wrote:

Any clues on why this would be set to anything other than 1500? That seems pretty standard. Why would the op find his set at 576?

576 is normally used for dial up. 1500 is used for cable modems and ADSL might require 1492. Without looking at what's on the wire, I couldn't guess why it's going to 576. Wireshark is handy for this sort of thing. If all else fails, he can have a script run automatically after boot up to reconfigure the MTU and start the DHCP client. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On 12/09/2012 11:51 PM, SCOTTSIMPSON1240 wrote:

From: "Cristian Rodríguez"

...

This does not make sense... either there is something wrong in your machine or your ISP is doing something very stupid as pushing a very reduced MTU via Router Advertisement..

I don't think it is the ISP (Comcast) because when I connect a Mac to the modem it gets IPv4 and IPv6.

Ok, then there is a bug anyway , because according to rfc2460 minimum mtu size for ipv6 is 1280 "IPv6 requires that every link in the internet have an MTU of 1280 octets or greater. " therefore whatever is handling this must return EINVAL and NOT set a wrong MTU.. likely a kernel bug worth looking at, -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On Sun, Dec 09, 2012 at 07:13:34PM -0800, Scott Simpson wrote:

On Dec 9, 2012, at 7:00 PM, Cristain Rodríguez <crrodriguez@opensuse.org> wrote:

...

therefore whatever is handling this must return EINVAL and NOT set a wrong MTU.. likely a kernel bug worth looking at,

Check my comment about another person seeing this same behavior. ifup/ifdown selection in 12.2 uses dhcpcd/dhclient and NetworkManager uses dhclient/dhclient. Most people today are using IPv6 so is anyone getting IPv6 addresses under ifup/ifdown (Case 1) or NetworkManager (Case 2)? I selected ifup/ifdown since I'm old school but you current SuSE guys probably select NetworkManager all the time.

Please file a bug report and add a link to this thread in the list archive at http://lists.openSUSE.org/opensuse/2012-12/msg00142.html Later reply to this thread again and include the bug ID. See https://en.openSUSE.org/Submit_a_Bug about how to submitting bug reports. Cheers, Lars -- Lars Müller [ˈlaː(r)z ˈmʏlɐ] Samba Team + SUSE Labs SUSE Linux, Maxfeldstraße 5, 90409 Nürnberg, Germany

Scott Simpson wrote:

Check my comment about another person seeing this same behavior. ifup/ifdown selection in 12.2 uses dhcpcd/dhclient and NetworkManager uses dhclient/dhclient. Most people today are using IPv6 so is anyone getting IPv6 addresses under ifup/ifdown (Case 1) or NetworkManager (Case 2)? I selected ifup/ifdown since I'm old school but you current SuSE guys probably select NetworkManager all the time.

I use ifup/ifdown on my desktop firewall and network manager on my notebook. My firewall uses a 6in4 tunnel to obtain IPv6 from a tunnel broker. Other computers on my network get their IPv6 config from my firewall via router advertisements. I don't use dhcp6 anywhere. I use ifup/ifdown on any computer that stays put on my local network. I use network manager on my notebook, as it will be connected to different networks via Ethernet or WiFi. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Herbert Graeber wrote:

You can select whether ifup/ifdown uses dhcpcd or dhclient: DHCLIENT_BIN in /etc/sysconfig/network/dhcp shall do that. I've set that and installed dhclient, but ps aux shows dhcpc is still running as well as dhclient. This is on 11.4.

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El 10/12/12 11:03, Herbert Graeber escribió:

Nevertheless it's a bug, because with dchcd it shall work, too.

When bringing the interface up, the kernel IMHO should pick if(is_ipv6) mtu = max(requested_mtu, IPV6_MIN_MTU); [...] or return an error. the userspace bits are not the main concern, the kernel should not accept an MTU less than IPV6_MIN_MTU in the first place. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org