Internet ProtoCOL Version 6 I/II PS2 2015 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 => 2128 = 3,4 × 1038 – 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: 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 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 https://apps.db.ripe.net/search/full-text.html IANA IPv6 Global Unicast Address Assignments http://www.iana.org/assignments/ipv6-unicast-address-assignments/ipv6-unicast-address-assignments.xml

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

Interface ID /0 /48 /64 /128 | Global Routing Prefix | Subnet | Interface ID | 1.–3. Quartet 4. Quartet 5.–8. Quartet Static Manual configuration, e.g. 2001:718:803:1::1 EUI-64 Extended Unique Identifier 64-bit Random Privacy Extensions – due to security reasons

EUI-64 EUI-64 The 64-bit Interface Identifier generated from the 48-bit MAC Address. MAC Address divided into two halves 00:01:02:aa:bb:cc The 7. bit in the 1. byte (U/L-Bit) inverted 02:01:02:aa:bb:cc FFFE inserted 0201:02FF:FEaa:bbcc

IPv6 Address Types 1/4 Special Addresses ::/128 Unspecified ::1/128 Loopback Listen on all network interfaces Local 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? IPv6 Address … Prefix + Interface ID Prefix Length Default Gateway Address DNS Server Address + DNS Search List

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

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Win 7)

Static IPv6 Configuration (Linux) Temporary configuration

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

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:5B21 2001:718:803:1::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 ping Loopback ping own NIC ping Default-GW ping DNS-Servers traceroute Windows: ping, tracert Linux: ping6, traceroute6

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

Dynamic Assignment Stateful DHCPv6 DHCPv6 Solicit DHCPv6 Advertise DHCPv6 Request 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: RA sent: a) periodically, b) reply to RS 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“ Only two addresses by now – the Global and Link Local address. Why another one? The Temporary address is used for outgoing communication (security reasons). How to disable the temporary address netsh int ipv6 set privacy disabled

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 642-902 Official Certification Guide. Cisco Press, 2010. ISBN 1-58720-253-0.