HopbyHop Options

1
Hop-by-Hop Options

• Router Alert
• Resource Reservation Protocol (RSVP)
• Multicast Listener Discovery (MLD)
• Jumbogram option
• Only relevant to IPv6 nodes with link-MTU gt 64K
• This option is used to send packets with more
  than 64K bytes of payload
• Jumbo Payload Length length of the packet,
  excluding the IPv6 header
• The IPv6 header length field must be set to 0

Option Data Length
Header Extension Length
Next Header
Option Type
Option Data
Jumbo Payload Length
C2
4
2
Multicast Addresses

• Multicast is used in the context of one-to-many.
  A multicast scope is new in IPv6.

112 bits
group ID
0 if permanent 1 if temporary
1111 1111
Flag
Flag
Scope
F
F
1 interface-local2 link-local3
subnet-local4 admin-local5 site-local8
organizationE global
8 bits
8 bits
Scope
3
Duplicate Address Detection (DAD)

• Duplicate Address Detection (DAD) uses Neighbor
  Solicitation to verify the existence of an
  address to be configured.

B
A
ICMP type 135 Src
0 ()
Dst solicited-node multicast of A Data
link-layer address of A
Query what is your link address?
4
Route optimization

• Mobile node can send binding updates to any
  correspondent node
• Correspondent node can send now packets directly
  to mobile node
• Route for entry in binding cache has two hops
• 1st hop care-of address of mobile node
• 2nd hop home address of mobile node
• Routing header is used with this information

Link B
Home Link Link A
Internet
Binding Update
Link C
Packet
Source
Source
1st hop
2nd hop
5
End-to-end session
End-to-end IPv6 session
IPv4-only network
IPv6-only network
IPv6-only network
IPv6 host
IPv6 host
Entry point
Exit point
IPv4
A
B
IPv6 network
IPv6 network
Tunnel
R1
R2
IPv6 header payload
IPv6 header payload
IPv4 header
IPv6 header payload