The MPLS WG Archive

[mld@horizon.dk]

Hi, 

well I have not read the spec in detail   but ip workes like this


ping is a aplication that uses a icmp echo-request and will get a icmp
echo-reply back TTL will always be valid ie a non zero value in the ip
header

for traceroute the outgoing packet could be a lot of different kind
traditionaly its a udp packet but it could be icmp echo-request to
(microsoft is doing this, they just have to do it in a different way)
the important thing for a traceroute packet is that it always has a TTL
value of zero, when you should respond to it and traceroute will usualy get
a icpm destination unreachable back with sub-code of TTL-exeded in transit
since the packet is droped due to TTL value is zero

ps i hope you remember how traceroute work.

/micke


At 11:03 2003-02-07 +0900, you wrote:

Hi ! 
  
I have some question for ping and traceroute in draft "Detecting MPLS Data
Plane Liveness". 
  
In draft, ping ICMP Message should reach the end of the path(Egress LSR). 
  
Ping Message is sent to the control plane of the egress LSR. 
  
And, Traceroute ICMP Message is sent to the control plane of each transit
LSR. 
  
If yes, How could I discriminate between two messages at each transit LSR ? 
  
Best Regards 
  
Ryu Ho Yong. 
Internet Department Technology 
Netwrok Labratory 
Electronics & Telecommunications Research Institue (ETRI)