On Thursday 29 Dec 2011 07:10:19 Lubos Kolouch wrote:
> walt, Wed, 28 Dec 2011 17:01:59 -0800:
> > Sometime in the last month or so (when I wasn't looking) my ~x86 and
> > ~amd64 machines quit working when I try to run wireshark or tcpdump,
> > etc, but I don't know exactly when or why.  (My amd64 machine still
> > sniffs packets normally.)
> > 
> > I get this same error from any packet sniffing app:
> > 
> > Can't open netlink socket 93:Protocol not supported
> > 
> > Strace shows that this is the failing system call:
> > 
> > socket(PF_NETLINK, SOCK_RAW, 12) = -1 EPROTONOSUPPORT (Protocol not
> > supported)
> > 
> > That makes me think of some missing kernel config that may have been
> > added or modified in recent kernels, so I tried gentoo-sources-3.0.6
> > (same as my working amd64 machine) with no joy.  Same error message.
> > 
> > Have I missed some important gentoo bulletin about networking recently?
> > Anyone have working packet sniffing on ~arch?
> 
> Hi,
> 
> If I remember correctly, I needed to set
> Networking support -> Networking options -> Network packet filtering
> framework (Netfilter) -> Core Netfilter Configuration -> Netfilter
> connection tracking support
> 
> It has been a while though, so it may be another option in the
> netfilter config - just try it :)
> 
> Lubos

tcpdump-3.9.8-r1 and kernel-3.0.6-gentoo works fine here with no errors.

$ cat /usr/src/linux/.config | grep CONNTRACK
CONFIG_NF_CONNTRACK=y
CONFIG_NF_CONNTRACK_MARK=y
# CONFIG_NF_CONNTRACK_EVENTS is not set
CONFIG_NF_CONNTRACK_TIMESTAMP=y
# CONFIG_NF_CONNTRACK_AMANDA is not set
CONFIG_NF_CONNTRACK_FTP=y
# CONFIG_NF_CONNTRACK_H323 is not set
CONFIG_NF_CONNTRACK_IRC=y
CONFIG_NF_CONNTRACK_BROADCAST=y
# CONFIG_NF_CONNTRACK_NETBIOS_NS is not set
CONFIG_NF_CONNTRACK_SNMP=y
# CONFIG_NF_CONNTRACK_PPTP is not set
# CONFIG_NF_CONNTRACK_SANE is not set
CONFIG_NF_CONNTRACK_SIP=y
# CONFIG_NF_CONNTRACK_TFTP is not set
CONFIG_NETFILTER_XT_MATCH_CONNTRACK=y
CONFIG_NF_CONNTRACK_IPV4=y
CONFIG_NF_CONNTRACK_PROC_COMPAT=y
CONFIG_NF_CONNTRACK_IPV6=y

HTH.
-- 
Regards,
Mick