hoplimit.seq - Verify that decrease hoplimt when the
encapulating packet is forwarded
Router
Before this test starts, run initialize.seq.
This test verifies that NUT decrease hoplimit when forward through tnnnel.
Network Topology
Link0
--------------------------
| |
TN NUT
| |
--------------------------
Link1
TN -- (Link0) -- NUT TN -- (Link1) -- NUT
--------------------- ------------------------
- encapsulation, and forwarding a packet
1.
===================>
ICMPv6 Echo Request
IPv6 Header
src address : TN LINK0 IPv6 global address
dst address : Off-link IPv6 global address
hoplimit : 64
2.
In NUT, received ICMPv6 Echo Request packet is encapsulated,
and forward IPv4 packet
3.
<<JUDGMENT>>
<===================
IPv4 packet encapsulating IPv6 packet
Outer Header (IPv4)
src address : NUT Link1 IPv4 address
dst address : Off-link IPv4 address
Inner Header (IPv6)
src address : TN LINK0 IPv6 global address
dst address : Off-link IPv6 global address
hoplimit : 63 (for ISDN router, 62)
- decapsulation, and forwarding a packet
4.
===================>
IPv4 packet encapsulating IPv6 packet
Outer Header (IPv4)
src address : Off-link IPv4 address
dst address : NUT Link1 IPv4 address
Inner Header (IPv6)
src address : Off-link IPv6 global address
dst address : TN LINK0 IPv6 global address
hoplimit : 64
5.
In NUT, received IPv4 packet is decapsulated, and forward
ICMPv6 Echo Request packet.
6.
<< JUDGMENT >>
<===================
ICMPv6 Echo Reply
IPv6 Header
src address : Off-link IPv6 global address
dst address : TN LINK0 IPv6 global address
hoplimit : 63 (for ISDN router, 62)
<< PASS >>
NUT decreased hoplimit
<< FAIL >>
NUT did not decrease hoplimit
perldoc V6evalTool