[j-nsp] EX 8200 deployment

[Pavel Lunin]

2010/3/22 Richard A Steenbergen <ras at e-gerbil.net>

> But what happens when you do:
>
> interface xe-1/0/0 {
>    vlan-tagging;
>    unit 101 {
>        vlan-id 101;
>        family inet {
>            address 1.2.3.4/24;
>        }
>    }
> }
>
> interface xe-2/0/0 {
>    vlan-tagging;
>    unit 101 {
>        vlan-id 101;
>        family inet {
>            address 2.3.4.5/24;
>        }
>    }
> }
>
> Commit check doesn't error on it at any rate, but does this share
> packets within a vlan 101 space automatically, or not?


The outgoing iface for this piece of config will be chosen using the dst mac
address of the next hop, which is behind a particular interface. There is no
L2 switching here at all. I can confirm EX3/4200 allow to do so.

The main difference of EXs is that they only can do one lookup. E. g. either
L3 or L2, not both. So you can not mix families for units on the same
physical port.

However if you do inet on the port, you don't need to care if any other
ports do ether-switching for the same vlan or something. That said, it seems
like you don't need to be aware of all that VLAN significance cauchemar as
poor CCIE candidates :)

A good workaround (not counting doubled port consumption, delay and the
cable and SFPs cost) you can split the L2 and L3 lookups into two steps with
a hairpin as Alexandre proposed. It is also a way to convert input policiers
to output (thanks, Alexandre!).

But I am not sure about counters. No way if you want to count packets routed
through RVI on a VLAN sprung across multiple trunk ports.

Richard, one more thing. What do you do with the crash dumps untarzipping
them on the router/switch itself? I have never done anything with them but
sending to JTA. I believe it can have a lot of sense to pick them and
discover yourself (though I've never tried), but why on the switch itself?
Am I missing something important?

--
Kind regards,
Pavel