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IPv6 Autoconfiguration Plug & Play Dream or Security Nightmare. Review of IPv6 Autoconfig. Defined in RFC 2461 All hosts implicitly have an IPv6 Link-Local address for each interface they have Host “I have a NIC, therefore I am” FE08::(EIU-64)
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IPv6 AutoconfigurationPlug & Play Dream or Security Nightmare
Review of IPv6 Autoconfig • Defined in RFC 2461 • All hosts implicitly have an IPv6 Link-Local address for each interface they have • Host “I have a NIC, therefore I am” • FE08::(EIU-64) Simple Corollary: therefore, a host without a NIC, is a non-entity
Review of IPv6 Autoconfig • Other network information obtained from the Router(s) on the local network • Host “Is there a router in the house” • ICMPv6 Type 133 – Router Solicitation • Router “I’m a router and here are the prefixs you can use” optionally “, and go talk to the DHCPv6 server” • ICMPv6 Type 134 – Router Advertisement
Review of IPv6 Autoconfig • The host combines the prefix information with a host address portion to form an IPv6 Address • Multiple Types of Host Addresses
IPv6 Address Types • Stateless (EUI-64) • RFC 2462 • Privacy Extensions (pseudorandom) • RFC 3041 • Stateful (DHCPv6) • RFC 3315
So what’s the problem? • Well do you know the devices that says it’s the router is really suppose to be the router? • If you get multiple answers (which you can) which is the right one?
So what’s the problem? • It could be a miss-configured host • LINUX, Widows, or what ever • Maybe with a tunnel that it want to HELP! other people use • More scary, could be a BAD guy claiming to be a router • Trying to setup a man-in-the-middle attack
But I’m not running IPv6! • Are you sure? • OSes are coming with IPv6 by default • Windows Vista • Mac OSX • Many LINUX • Many other UNIX
But I’m not running IPv6! • So you probably have hosts asking for an IPv6 router on your network right now • All you need is a missconfigured host or a bad guy on your network and your hosts are doing IPv6
What about SEND?IPv6 Secure Neighbor Discovery • RFC 3971 • It will Secure this, and more! • But!!!! • There are not many, if any, implementations • Certs & PKI • Do I need to say more
What about SEND?IPv6 Secure Neighbor Discovery • Will work in a well controlled mostly closed network • Not the definition of your typical University Network • Probably not workable on a visitor or guest network even if your primary network is securable in this way
A Solution • Block IPv6 Router Advertisements on ingress to access switch port for hosts • Can be done today with Cisco 3750, 3750-E, 3560, and 3560-E switches • IOS 12.2(25)SED Advanced IP Services (only) or greater code • I tested on 3750s with 12.2(40)SE AdvIPServ
IOS Config Snip ipv6 access-list v6_Access_IN deny icmp any any router-advertisement permit ipv6 any any interface GigabitEthernet1/0/1 switchport access vlan 247 ipv6 traffic-filter v6_Access_IN in
A Different Problem • I said “Advanced IP Services” • The upgrade from “IP Base” is $6,995 list per switch • We have about 3500 – 3750G-24TS • This is about $24M list • We’re talking to to the 3750 Business Unit at Cisco
Other Solutions • Turn off IPv6 on your host if your not using it • Not a great solution • Not a solution at all, if you need/want to do IPv6 • But can you really insure that you have done this
Other Solutions • Monitor for bogus IPv6 Router Advertisements • Ala XArp type IPv4 ARP monitoring software • IPv6 Routers would be perfect device to do this, track the other router • maybe even do an SMNP trap – maybe not
Talk to you Switch Vendor • We all need to be talking to our Vendors • Talk to them about how you want IPv6 to work 1,2, or 3 years from now • Make IPv6 a requirement in all your purchases • Test the features
IPv6 Support Priority List for Vendors • Basic Functionality – you can pass IPv6 at all • Security – Comparable security feature to IPv4 • IPv6 manageability • Full IPv4 feature parity
IPv6 Access Switch Features • IPv6 Aware Layer2 ACLs • DHCPv6 Snooping • IPv6 Neighbor Discovery Validation • MLD2 Snooping • IPv6 Aware QOS features
Conclusion • Start thinking about IPv6 as part of your normal network • Think about it in the same ways as IPv4 • However, take the opportunity to rethink how you are doing your normal networking • Talk to your Vendors early and often