INTERNET PROTOCOL Version 6 I/II IPIAC 2013 Martin Pokorný

Reasons for a new IP protocol IPv4/IPv6 – Addressing & Packet forwarding Why a new IP protocol? IPv4 – IPv4 address space exhaustion IPv6 – IPv6 address … 128 bits => = 3,4 × – Address space aggregation … IANA site – Simplified header, no broadcasts, …

IPv6 Address Notation General form hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh 8 × hhhh … Blocks, Segments, Quartets => 16 bits 32 × h … Hexadecimal digit (0-9, a-f) Example 2001:0000:a000:0001:0000:0000:0000:0000 Two rules to make the address shorter: 1. Leading zeros in a quartet can be omitted, one number must remain. 2001:0000:a000:0001:0000:0000:0000:0000 → 2001:0:a000:1:0:0:0:0 2. One or more consecutive quartets with a null value can be replaced with a double-colon (::), once in the whole address only. 2001:0:a000:1:0:0:0:0 → 2001:0:a000:1::

Network Prefix and Interface-ID IPv6-Address | Network Prefix | Interface ID | ← Prefix Length → No „subnet mask“ … Prefix length, Notation /x Network address… Interface ID = 0 Example Host-Address 2001:718:803:1:a00:27ff:fefc:152 Network-Address 2001:718:803:1::/64

Address Assignment – Global Unicast Global Unicast Addresses: prefix 2000::/3 reserved Global Unicast Address Assignment Strategy IANA (/3) -> RIR (/23) -> LIR (/32) -> Customer (/48) Global Routing Prefix (Site Prefix): /48 MENDELU Example IANA Global Unicast … 2000::/3 RIPE NCC RIR … 2001:600::/23 CESNET LIR … 2001:718::/32 MENDELU … 2001:718:803::/48 RIPE Database IANA IPv6 Global Unicast Address Assignments

Subnet Addressing /0 /48 /64 /128 | Global Routing Prefix | Subnet | Interface ID | 4. Quartet 1.–3. Quartet 5.–8. Quartet

Interface ID /0 /48 /64 /128 | Global Routing Prefix | Subnet | Interface ID | 4. Quartet 1.–3. Quartet 5.–8. Quartet a)StaticManual configuration, e.g. 2001:718:803:1::1 b)EUI-64Extended Unique Identifier 64-bit c)RandomPrivacy Extensions – due to security reasons

EUI-64 The 64-bit Interface Identifier generated from the 48-bit MAC Address. 1.MAC Address divided into two halves 00:01:02:aa:bb:cc 2.The 7. bit in the 1. byte (U/L-Bit) inverted02:01:02:aa:bb:cc 3.FFFE inserted0201:02FF:FEaa:bbcc

IPv6 Address Types 1/4 Special Addresses ::/128Unspecified ::1/128Loopback Listen on all network interfacesLocal communication

IPv6 Address Types 2/4 Global Unicast Addresses 2000::/3(not only this one…) „Global“ => world-unique address „Unicast“ => identifies one network interface card Routable=>

IPv6 Address Types 3/4 Link Local Unicast Addresses FE80::/10 | FE80 (10 bits) | 54 × 0 | Interface ID | Local communication, no forwarding

IPv6 Address Types 4/4 Multicast Adresses FF00::/8… a group of hosts Address scope (e.g.) FF02 … Link-Local FF05 … Site-Local FF02::2 … All IPv6 Routers FF02::1 … All IPv6 Hosts

IPv6 Configuration Assignment 1 What parameters are needed for a typical IPv6 host? 1. IPv6 Address … Prefix + Interface ID 2. Prefix Length 3. Default Gateway Address 4. DNS Server Address + DNS Search List

IPv6 Configuration Assignment 2 How can the IPv6 host get these parameters? A) Static/Manual Configuration … Infrastructure Devices B) Dynamic Assignment … End-Hosts

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Linux) Temporary configuration

Static IPv6 Configuration (Linux) Permanent configuration Debian-based: /etc/network/interfaces RedHat-based:/etc/sysconfig/network-scripts/ifcfg-eth0

Static IPv6 Configuration (Cisco) Router(config)#ipv6 unicast-routing Router(config)#int Gi0/1 Router(config-if)#ipv6 addr 2001:718:803:1::1/64 Router(config-if)#no shutdown Router#show ipv6 int brief GigabitEthernet0/1 [up/up] FE80::32E4:DBFF:FEEB:5B :718:803:1::1 Router#show ipv6 route C 2001:718:803:1::/64 [0/0] via GigabitEthernet0/1, directly connected L 2001:718:803:1::1/128 [0/0] via GigabitEthernet0/1, receive L FF00::/8 [0/0] via Null0, receive Router#show ipv6 int gi0/1 GigabitEthernet0/1 is up, line protocol is up IPv6 is enabled, link-local address is FE80::32E4:DBFF:FEEB:5B21 No Virtual link-local address(es): Global unicast address(es): 2001:718:803:1::1, subnet is 2001:718:803:1::/64 Joined group address(es): FF02::1 FF02::2 FF02::1:FF00:1 FF02::1:FFEB:5B21 EUI-64 possible as well … R(config-if)# ipv6 addr 2001:718:803:1::/64 eui-64

Troubleshooting 1. ping Loopback 2. ping own NIC 3. ping Default-GW 4. ping DNS-Servers 5. traceroute Windows: ping, tracert Linux: ping6, traceroute6

Lab 1 Dual Stack (IPv4 + IPv6) – Static configuration

Dynamic Assignment Stateful DHCPv6 1. DHCPv6 Solicit 2. DHCPv6 Advertise 3. DHCPv6 Request 4. DHCPv6 Reply DUID (DHCP Unique Identifier) Problem with the Default-Gateway SLAAC = StateLess Address AutoConfiguration Stateless DHCPv6 DNS Servers + Search List

SLAAC End host needs: 1. Prefix … ok 2. Interface ID … missing 3. Prefix length … ok 4. GW IPv6 Address … partially 5. DNS Information … missing* RA sent: a) periodically, b) reply to RS * RFC 6106 – DNS info inside the RA message; or Stateless DHCPv6

SLAAC - RS Router Solicitation

SLAAC - RA Router Advertisement

SLAAC – Interface ID EUI-64

SLAAC – Interface ID Random Random -> EUI-64 netsh int ipv6 set global randomizeidentifiers=disabled

SLAAC – „Temporary IPv6 Address“ Temporary IPv6 Address How to disable the temporary address netsh int ipv6 set privacy disabled Only two addresses by now – the Global and Link Local address. Why another one? The Temporary address is used for outgoing communication (security reasons).

SLAAC – Default Gateway

Lab 2 Dual Stack (IPv4 + IPv6) – SLAAC End-Hosts

IPv6 Header Compared to the IPv4-Header: longer, but simpler, fewer fields no checksum fixed length (40 bytes) extension headers

Lab 3 IPv6 Header Analysis + Encapsulation Analysis

Questions

References ODOM, W. CCNP ROUTE Official Certification Guide. Cisco Press, ISBN