[HECnet] HECnet performance....

[Johnny Billquist]

On 2013-01-09 17:19, Peter Lothberg wrote:
On 1/9/2013 1:59 PM, Peter Lothberg wrote:
On 1/8/2013 9:01 PM, Peter Lothberg wrote:
Set up a (cisco) tunnel to 130.238.19.60 (and tell me your side IP
address).
I think it's time to come up with something a little better to track all
these.

Thoughts?
Build a tool that takes requests and generates configs (full mesh) and
pushes them to the routers.

(maybe we can have the router configs in a wiki?)

Great mind think alike. :)

I had though pretty much exactly that.

If we are going to do that, however, we should decide on a range of
tunnels to use.

For example on my router, 0, 1 and 2 are DECnet tunnels, 3 is my IPv6
tunnel to HE and 4 is a DECnet tunnel.

Re-pushing the configs in this case would be ugly, so I think it would
be wise to say, tunnels X through Y are dedicated to auto-DECnet tunnels
so I can write cisco configs to deal with that appropriately.

I will write something. :)

-brian



If you knew the capability (what kind of tunnels) a node can support and you have
a fixed priority for in what order to chose, given two nodes you can automatically
determine the required tunnel type and don't need to encode it in to you global
description as it's a pair-wise local matter..... -:)

A big part of the general problem is that all these numbers are local for each end of connections, so that you can get very asymetrical setups.

Also, the metrics are set on the circuit, and not individual destinations. While this worked more or less ok for DEC back in the day, with the bridge, the cost of two different destinations over the same circuit could in reality be very different.

In the end, it boils down to a couple of things for tweaking the costs.
1. Preference of tunnel or bridge. If you prefer using the bridge, then just set the ethernet circuit cost lower than the tunnel. The tunnel can be either a multinet tunnel, or a tunnel on the cisco.
2. If the rest of your network isn't on the same ethernet as the bridge is, then you can use tweaks and control to your hearts content.
3. If the rest of your network don't have some other path out, then it don't matter if the ethernet circuit cost is high, so still feel free to tweak it as needed.

I think that you should be able to tweak the costs freely almost all the time, without any issues. However, you will sometimes not get the results you are looking for if the other end, and all intermediate nodes have also set their costs based on similar views as yours.

	Johnny