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On Sun, 2013-08-04 at 13:28 -0700, Eduardo Bonsi wrote:
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Hello Everyone,
I have some questions about ipV6 transition and DNS configuration!
I am preparing to make my transition to a dual stack ipv4, ipv6 and I
have some concerns in regards to the security of the network since ipv6
do not have NAT. My ISP gave me a Global
2602:000:000:000:000:000:000:000/64 Range and I can just turn on ipV6 on
the router and set the network to automatic on the computer and I am
connected through what they call a SLAAC ipV6 automatic conf network,
that runs using the machine MAC address in which I am not very happy to
adopt. I well know there is a way to mask the MAC address to random
addresses as a security measure but I am still not happy about it.
Beside, there are all the BIND DNS configuration that needs to be routed
or I am stack with a slow broke SLAAC connection that it works, but not
to the level of the a DNS Server that I want to achieve. Therefore, as a
network design after analyzing my options, I have decided to use the
static ipv4, ipV6 deployment approach that uses my ipV6 with the 3 last
bit of the ipv4 NAT addresses already in place. This static option does
not expose the machine MAC addresses. However the addresses are directed
connected through ipV6 bypassing the NAT environment. On BIND, the only
change I have in the named.conf file is the,
listen-on-v6 { any; };
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<BR>
listen-on-v6 ::1 and your dns server ipv6 address<BR>
<BR>
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Therefore, here are my questions:
1. I am open to ideas or anything you think is best choosing the best
internal network design for ipV6.
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Static IP assignments on your LAN, as far as your ISP is concerned they will just route your /64 via your routers IP. sure you can do auto assignments, but I think if they are servers its best to do static.<BR>
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2. Since this static ipV6 deployment lacks the non-rotatable NAT
environment, what are the security measures to take on BIND in regards
to the recursive issues on ipV6?
</PRE>
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<BR>
with ipv6, no more do you have security by accident (NAT) if you have a /64 your router will route for all, forget all the bad habits of the lazy ipv4 days, now you need to configure access lists on your router, but also play it safe and configure firewalls on each machine, especially if they are winblows boxes<BR>
<BR>
<BR>
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3. Are there any other security issues that should I considerate?
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Don't be over aggressive with filtering, you do not mention the OS, but if its linux -<BR>
<BR>
ip6tables -P INPUT DROP<BR>
ip6tables -P OUTPUT ACCEPT<BR>
ip6tables -P FORWARD DROP<BR>
<BR>
ip6tables -A INPUT -i lo -j ACCEPT<BR>
ip6tables -A INPUT -s fe80::/10 -j ACCEPT <BR>
ip6tables -A INPUT -d ff00::/8 -j ACCEPT<BR>
ip6tables -A INPUT -p tcp -m tcp --dport 22 -m state --state INVALID,NEW -j LOG<BR>
ip6tables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT<BR>
<BR>
... insert ACCEPT's for your lan and whatever other ipv6 addresses you need with full access here...<BR>
<BR>
ip6tables -A INPUT -p udp -d you:ipv6:dns:server:address --dport 25 -j ACCEPT<BR>
ip6tables -A INPUT -p tcp -d you:ipv6:dns:server:address --dport 25 -j ACCEPT<BR>
<BR>
<BR>
and.. importantly..<BR>
ip6tables -A INPUT -p icmpv6 --icmpv6-type 1 -j ACCEPT # Destination unreachable<BR>
ip6tables -A INPUT -p icmpv6 --icmpv6-type 2 -j ACCEPT # Packet too big<BR>
ip6tables -A INPUT -p icmpv6 --icmpv6-type 3 -j ACCEPT # Time exceeded<BR>
ip6tables -A INPUT -p icmpv6 --icmpv6-type 4 -j ACCEPT # Parameter problem<BR>
ip6tables -A INPUT -s your:gateway:ip -p icmpv6 --icmpv6-type 135 -j ACCEPT<BR>
ip6tables -A INPUT -s your:gateway:ip -p icmpv6 --icmpv6-type 136 -j ACCEPT<BR>
<BR>
You *will* need the above accepts regardless since your default policy is DROP, if not, you may find ipv6 reachable problems, in fact, you may not even be able to connect outbound without types 135/136 (neighbour discovery)<BR>
<BR>
<BR>
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