Tanks for your help. I have another question now. I saw the following
sentences in the same draft(draft-ietf-mpls-ldp-06.txt):
"" An LDP Message is malformed if:
- The Message Type is unknown.
If the Message Type is < 0x8000 (high order bit = 0) it is an
error signaled by the Unknown Message Type Status Code.
If the Message Type is >= 0x8000 (high order bit = 1) it is
silently discarded.
Any value of Message type(error for <0x8000,discard for >=0x8000) causes LDP
message malformed, then which values
are right for message type?
Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu wrote:
On Tue, 07 Mar 2000 18:23:20 +0800, jinglin <jinglin(_at_)263(_dot_)net>
said:
I cannot understand the meaning of the words:
" 2. LSR1 determines whether it will play the active or passive role
in session establishment by comparing addresses A1 and A2 as
unsigned integers. If A1 > A2, LSR1 plays the active role;
otherwise it is passive. "
I want to know what kind of address of A1&A2, IP address or TCP port
No.? why the role is determined by the size of A1 &A2?
I don't know what A1/A2 are, but a IP/port tuple sounds like a good
guess (*PLEASE* read the draft to see if I am right). This would have
the property that the tuples represending the two ends of the connection
would be almost guaranteed to be different (ignoring the boundary
condition of connecting a port to itself).
A1 and A2 are both almost certainly the same *size* as in "number
of bits used to represent them". What is being compared is the *value*
of the two addresses. mlps needs a fast way to determin which will
be the active/passive role. Whichever has the higher value address
becomes active. If these were telephones, we'd say "compare the two
phone numbers as integers, whichever has the higher number acts
as the active end".
Valdis Kletnieks
Operating Systems Analyst
Virginia Tech