IPV6 Routing Protocols Lab Tips

EIGRPV6

  • You must specify the RID in the Router Process as a IPV4 format (x.x.x.x).
  • You must do a no shutdown under the routing process.
  • Can enable under the interface as ipv6 eigrp [as no.]

OSPFv3

  • Neighbour statement done under the interface.
  • Authentication is done using IPSEC and not MD5
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IPV6 – Decimal and Hex conversions Lab Tips

* To convert a decimal (IPV4) into a Hex (IPV6)

e.g. 192.168.100.0

1 – – 168 / 16 = 10.5 we are only interested in everything before the decimal point which is 10. 10 in hex is A.

2 — 10.5 -/minus 10 (everything before decimal point) = 0.5

3 — 0.5 x 16 = 8

4 — 168 in hex is A8

* To covert Hex (IPV6)  into Decimal (IPV4)

e.g. A8

1 — A8 split up on it’s own is 10 and 8

2 — 10 in binary is 1010

3 — 8 in binary is 0100

4 — combine them both 1010 0100

5 – – 128+0+32+0+0+8+0+0 = 168

6 — A8 in decimal is 168

IPV6 – Multicast Lab Tips

  • Enable this using ipv6 cef, ipv6 unicast-routing and ipv6 multicast routing.
  • The above latter command will enable PIM Sparse-mode on all ipv6 interfaces! Unlike ipv4 you had to do the ip pim sparse-mode on each interface.
  • To join a multicast group use ipv6 mld join-group which is the same as ip igmp join-group.
  • Auto-rp no longer exists. only static and BSR. Same commands used as in IPV4.
  • Configuring the RP will create a GRE tunnel! in ipv4 the router sends a join request to the RP by encapsulating it in a unicast. in IPV6 a GRE tunnel is created instead.

IPV6 – Network Setup Lab Tips

  • Always do IPV6 unicast-routing to enable IPV6 on router and switches.
  • Switches require sdm prefer dual-ipv4-and-ipv6 default to enable IPV6 (will require a reboot)
  • Always hard code the interface link-local address e.g. FE80::1 link-local as most routing protocols uses the link local address when forming adjacencies (ospf) and / or sourcing updates. Assign the same link-local address on all the IPV6 interfaces of that router as it will make life easier e.g. FE80::1 link-local on all IPV6 interfaces of R1, including tunnel interfaces
  • Exception to the above is when configuring eui-64 address, do not hard code the link-local as the dynamic address will not be created.
  • Make sure link local addresses are mapped in the Frame Relay statements as it will break OSPFV3 across frame-relay.
  • Frame-relay broadcast statement only need to be used once per DLCI, so no need to use it for both the link-local and global address map statements.
  • IPV6 does not use Arp, it uses Neighbour Discovery which relies on ICMP. If you see nothing under show iv6 neighbour then ping the destination router and you should see that show command populate. This is basically equivalent to a show ip arp
  • Site Local address starts with FEC0

 

IPV6 Crib Notes

These are my ‘crib notes’ that I’ve made to serve as a last minute refresher. Please forgive the grammer / spelling as I did not develop these notes with publishing in mind.

IPV6

***theory***

  • Anycast address: assigned to multiple interfaces & delivered to closes host that shares that address
  • (Aggregate able) global unicast address  (001)= IPV4 Public unicast address. Are routable to internet and can be summarised.
  • Multicast (1111 1111 or FF00::/8)
  • Link local (1111 1110 10 or FE80::/10) – Small scope, use to address a physical link (private address)
  • Site Local (1111 1110 11 or FEC0::/10)  – Allows devices in same organisation to exchange data = IPV4 private addresses
  • Loopback test (127.0.0.1) = ::1 OR 0:0:0:0:0:0:0:1
  • Unspecified / unknown address = ::/128
  • Default route =::/0
  • SLA – Site level aggregator – subnet for IPV4
  • IPV4 compatible address  – first 96bit are 0
  • IPV4 vs. IPV6: uses 128 bit address (16 bit hex). IPV4 uses 32 bit address. IPV4 has DHCP. IPV6 has Auto configuration (state and stateless)
    • Stateful – from server
    • Stateless – IPV6 host configures it own link-local. Does this by using FE80::0 followed by it MAC add for interface identifier e.g. FE80:ABCD:1234:5678. Once done, send (NS FF02::1 – all nodes) Neighbour Solicitation message to see if any host has same link local address.  If they do, that host sends a NA Neighbour Advertisement. The original host will then disable it local link address as part of DAD – Duplicate address detection procedure. It then sends a (RS FF01::2 – All routers multicast) Router Solicitation on to the segment once it happy it has a unique local link address.  The router then sends RA Router Advertisement which has additional information for the host to complete auto configuration
    • Header fields: 8 in IPV6
      • Version (set to 6). Traffic class (equivalent to ToS in IPV4), flow label (new. Allows packets in a flow to be marked), payload length (IPV4 equiv is Total Length Field), Hop Limit (equiv to IPV4 TTL field), Next Header (equiv to IPV4 protocol field), SAD & DAD NOW 128 bits!
      • IPV4 not in IPV6: Header Length, Identification, Flags, Fragment Offset, Header Checksum
      • IPV6: Has IPSec built in. IPV6 useful for IP Phones, GPS etc
      • IPV6 addressing (shortening):
        • Zero Compression: can condense consecutive zero with two colons (can only do ONCE). E.g.
          • 1234:1234:0000:0000:0000:0000:3456:3434
          • 1234:1234::3456:3434
  • Leading zeros can be compressed E.G.
    • 1234:0000:1234:0000:1234:0000:0123:1234
    • 1234:0:1234:0:1234:0:123:1234
  • Use both E.g.
    • 1111:0000:0000:1234:0011:0022:0033:0044
    • 1111::1234:11:22:33:44
    • IPV6 address convert to IPV4
      • ::D190:4E71
      • D1 = 13 X 16 + 1 x 1 = 209. 90 = 9 x 16 + 0 x 1 = 144. 4E = 4 x 16 + 14 x 1 = 78. 71 = 7 x 16 + 1 x 1 = 113 = 209.144.78.113
      • OPSF V3 – enabled on interface (unlike v4, enabled on router). Uses IPV4 address as it RID
      • MIGRATE IPV4 – IPV6
        • Dual Stack: Runs both IPV4 & IPV6 on an interface
        • 6to4 tunnel: automatic, session torn down when it ends & scalable. IPV6 encapsulated in IPV4 packet (protocol 41) through core. Uses 2002 + router IP address in hex. E.g. 2002:1234:83cd::/48
        • NAT PT

***commands***

  • R1 (Config)# IPV6 unicast-routing

Enables IPV6 on a router

  • R1(Config-if)# ipv6 ospf area 0