Dear BIRD Developers,
I am currently experimenting with custom BGP attributes using bytestring type
within a topology that consists of 8 routers. My goal is to display and handle
the newly added custom attributes and be able to see the value for each router
in all other routers, like the AS_path idea:
router1: 50
router2: 50 35
router2: 50 35 70
Because I want to reach a point where I can decide the lowest value for this
cutom attribute and choose the best path based on that lowest value, but the
problem is that I can't perform operations on attribute type bytestings due to
implementation limitations. Now I have two main questions:
1.
Working with bytestring values to be able to decide the best path based on the
lowest total path cost we have:
*
Is there a recommended way to parse, compare, or extract numbers from a
bytestring attribute within a BIRD filter? And how?
*
Currently, the raw output prints hexadecimal sequences (e.g., 31:30). How
should these be decoded/processed for comparisons?
*
How can I apply this idea using the bytestring type to add a value to each
router and then advertise it to every other router (in the topology of 8
routers) to decide what is the best path to take based on the lowest cost value
we have?
2.
Preference logic example:
*
How can a bytestring attribute be integrated into preference calculation in a
filter?
*
The documentation shows how to set preference based on integers or communities,
but I couldn’t find a concrete example for bytestring. Could you provide a
minimal example filter to illustrate this in order to prefere the path that has
the lowest values?
Any guidance or best practices on working with bytestring attributes for
routing decisions would be greatly appreciated.
Best regards,
Yazan
