A and B are connected via the same multi-access media. It is technically
possible for B to tell A "you can reach 172.16.16.0/24 on the same media
that you receive this update on". However what people seem to be saying
is that there is no dynamic routing protocol that implements this.
Ralph Doncaster
principal, IStop.com
There are two solutions to your dilemma:
- Route via B
- Add A to 172.16.16.0/24
It's not a matter of dynamic routing, it's just the way subnets work.
If you want all the hosts to be able to talk to each other directly,
put them all on the same subnet.
That you don't want to accept either solution doesn't mean that there
is no solution. "I want to define subnets, but I want hosts on said
subnets to ignore their boundaries" does not make sense.
-c
No its not possible to say you can reach the subnet on the same media...
IP maps to the [Ethernet] with ARP, but before a packet is passed down to MAC
via ARP it is routed and if there is no route to the connected ethernet then it
will necessarily need to use the other router.
You must have the route before you can look at passing it to the media..
Steve
A and B are connected via the same multi-access media. It is technically
possible for B to tell A "you can reach 172.16.16.0/24 on the same media
that you receive this update on". However what people seem to be saying
is that there is no dynamic routing protocol that implements this.
Nope, you need to have IP route for it. If you choose not to tell the second
router that it can do it, it would never even try.
Repeat after me "My router does not call ms. Cleo to find out what I want.
Router follows my instructions to the letter. I forgot to tell my router to
do something. It therefore refused to do that something. I shall tell my
router to do what I want it to do. It will follow my direct instruction."
Now either configure a secondary IP on the second router, or create IP
route pointing to the router that knows how to get to the destination.
Alex
It seems I'm not the only idiot asking these types of questions.
I found there's a whole RFC about it. http://www.ietf.org/rfc/rfc1433.txt
-Ralph
Please do NOT confuse PHYSICAL plumbing with LOGICAL plumbing.
Based on your description, router A and B ARE NOT on the same
broadcast domain, with respect to 172.16.16/24.
THey are on the same broadcast domain as 10.10.10.0/30
But thats it.
In otherwords, No it is NOT technically possible for B to tell
A that what it wants is on the same media.
Welcome to one of the few down falls of loading up multiple nets
on the same physical interface.