Re: nd6_setmtu0: new link MTU on iwn0 (576) is too small for IPv6 which needs 1280

[christos%astron.com@localhost (Christos Zoulas)]

In article <CAEJNuHwUsHp3V19eFvJ-D9Dt6Fu172OJVMtSL7k+k=vYJdUcmw%mail.gmail.com@localhost>,
Ottavio Caruso  <ottavio2006-netbsd%yahoo.com@localhost> wrote:
>Hello,
>
>uname -a:
>NetBSD  6.1.5_PATCH NetBSD 6.1.5_PATCH (GENERIC) amd64
>
>I have a problem with wireless connection and Netbsd that I don't have
>with Windows 7 and Linux.
>
>In the console I see:
>nd6_setmtu0: new link MTU on iwn0 (576) is too small for IPv6 which
>needs 1280
>iwn0: discarding oversize frame (len=1484)
>
>In "ifconfig iwn0" I have:
>
>iwn0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 576
>ssid TP-LINK_E6D338
>powersave off
>bssid 00:27:19:e6:d3:38 chan 6
>address: 00:21:5c:55:ee:9d
>media: IEEE802.11 autoselect (DS5 mode 11g)
>status: active
>inet 192.168.1.108 netmask 0xffffff00 broadcast 255.255.255.255
>inet6 fe80::221:5cff:fe55:ee9d%iwn0 prefixlen 64 scopeid 0x2
>
>Before connecting to the router the mtu was 1500 as it should be.
>
>I can connect to the router but cannot browse any website.
>
>I have manually changed the mtu on iwn0 to 1500 but I still have the
>same problem.
>
>I have removed all references to ip6 in rc.conf and rebooted the pc
>but no avail.
>
>I have played with the "ip6mode" value in rc.conf, setting it to
>"autohost" also to no avail.
>
>I have a good connection with the router and can ping any website, but
>I can't traceroute or browse any website.
>
>I have used Netbsd in the past with various routers and I've never had
>any problem.
>
>Any help willl be appreciated.
>

Try turning off mtu discovery via sysctl.... Perhaps the router or
something else is causing that. Can you ping the router? What size
packets will the router accept (ping with different sizes)?

christos