Date: Thu, 12 Feb 2009 13:09:34 -0500 From: Steve Bertrand <steve@ibctech.ca> To: ipfreak@yahoo.com Cc: freebsd general questions <freebsd-questions@freebsd.org> Subject: Re: ipv6 and freebsd Message-ID: <499465DE.4050604@ibctech.ca> In-Reply-To: <461864.28779.qm@web52109.mail.re2.yahoo.com> References: <461864.28779.qm@web52109.mail.re2.yahoo.com>
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gahn wrote:
> What shall I do to accomplish this on FreeBSD?
For clarification and completeness, here is exactly what I did:
First, config the router (Cisco):
interface FastEthernet0/0
ip address 192.168.3.2 255.255.255.0
duplex auto
speed auto
ipv6 address 2607:F118:A::1/64
ipv6 address FEC0:10::1/64
ipv6 nd ra-lifetime 210
ipv6 nd prefix 2607:F118:A::/64
ipv6 nd prefix FEC0:10::/64
Next, on the host, ensure we are properly prepared:
# sysctl -a net.inet6.ip6.accept_rtadv
net.inet6.ip6.accept_rtadv: 1
# ndp -i fxp0
linkmtu=1500, maxmtu=1500, curhlim=64, basereachable=30s0ms,
reachable=39s, retrans=1s0ms
Flags: nud accept_rtadv
Ensure there is not a blanket ICMP filter on the host, by pinging the
link local address from the router (even if you can ping, it is still
possible that ICMP type 9 are being blocked):
# ping fe80::20d:60ff:fe4c:81ca
Output Interface: FastEthernet0/0
Packet sent with a source address of FE80::20A:F4FF:FE0B:B109
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/0 ms
Ensure we see RAs on the wire:
# tcpdump -n -i fxp0 ip6
listening on fxp0, link-type EN10MB (Ethernet), capture size 96 bytes
09:30:50.820717 IP6 fe80::20a:f4ff:fe0b:b109 > ff02::1: ICMP6, router
advertisement, length 96
Capture the entire packet with the RA information to make sure that the
router is actually sending the prefixes we want to autoconf. Dump this
info into a file, so we can scp it to our workstation to read it into
Wireshark:
# tcpdump -n -i fxp0 -s 0 -w /var/log/test.pcap ip6
What does Wireshark tell us about the advertisement:
ICMPv6 Option (Prefix information)
Type: Prefix information (3)
Length: 32
Prefix length: 64
Flags: 0xc0
1... .... = Onlink
.1.. .... = Auto
..0. .... = Not router address
...0 .... = Not site prefix
Valid lifetime: 2592000
Preferred lifetime: 604800
Prefix: 2607:f118:a:: <----------------***
ICMPv6 Option (Prefix information)
Type: Prefix information (3)
Length: 32
Prefix length: 64
Flags: 0xc0
1... .... = Onlink
.1.. .... = Auto
..0. .... = Not router address
...0 .... = Not site prefix
Valid lifetime: 2592000
Preferred lifetime: 604800
Prefix: fec0:10:: <----------------***
So by this point, we've confirmed that everything is in order. I don't
know if FreeBSD will autoconf if the 'L' bit (Onlink) flag is set to 0,
so check that too.
Let's see our ifconfig output:
# ifconfig fxp0
inet6 fe80::20d:60ff:fe4c:81ca%fxp0 prefixlen 64 scopeid 0x1
inet 192.168.3.1 netmask 0xffffff00 broadcast 192.168.3.255
inet6 2607:f118:a:0:20d:60ff:fe4c:81ca prefixlen 64 autoconf
inet6 fec0:10::20d:60ff:fe4c:81ca prefixlen 64 autoconf
The last thing to try, is to ping6 the known IPv6 address of the router
from the host. Perhaps ifconfig is not displaying the learnt addressing
information until it is used. (This situation did come up for me, but it
may have been a coincidence in timing. I haven't been able to reproduce it).
Steve
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