[HECnet] Mapping - getting close

[Peter Lothberg]

On 2013-01-12 16:10, Peter Lothberg wrote:
If you ask me, I think this idea is dead. You cannot get a good
representation of how the topology really is from trying to walk nodes
using NCP.

(remove bridged ethernet that are not point-to-point with only 2
nodes).

Walk through the "known cir" and then "cir char" and build your own
connectivity tree with the metrics.

Plot all links

Apply DECnet routing rules and Colour the links that carry traffic
with the current metrics and/up/down condition, use two colours, one
for transmitt one for receive (as links can end up being simplex).

Well, it all depends on what you want to know. If you want to properly 
understand the topology you also want to represent the topology of 
bridged ethernet segments, as well as ethernets in general. NCP don't 
have any clue about this.

Sure, if you want to only have Multinet ptp links, then it's easy. But 
that would a rather severe restriction on the network technology.

We have ethernets (both bridged and local), as well as Cisco tunnels. 
Both of which walking with NCP fails on.

NCP don't fail on DECboxes on ethernets. 

The plotting thing would do the right thing even on the ethernet, even
with the ethernet it ended up being a simplex path for some
multi-homed sites. 

There are two ways of represnting the the Ethernet,

          1 You draw it as a bus ignore that the links to it have
          different characteristics.

          2 You drow it as all the point-to-point links it represents. 

          	Look how IP handles Ethernet, it builds simplex TX only point
          	to point links using ARP and a dest-ip address to MAC address
          	mapping. 

-P