On 8/27/2012 2:10 PM, Ruben Laban wrote:
On 8/27/2012 1:58 PM, Ruben Laban wrote:
Hello,
I'm currently performing some experiments to find the "best" way to inter-connect a bunch of routers using a shared medium. A common scenario would be a set of 4 routers, for instance a pair of border routers and a pair of core routers. I'd like either a full-mesh or circle topology. Putting all nodes in a /29 isn't ideal because of the DR/BDR/etc stuff. I want all nodes and links to be treated equally. Using point-to-multipoint sounds like a decent solution. I can configure several sessions on a single link without interference, up to the point where the circle is created. Like this:
A - B | | D - C
However, if I try to add a link between A and C, things start to go not as expected. A already has 192.168.255.2/31 (towards B) and 192.168.255.4/31 (towards D) configured. If I add 192.168.255.10/31 (towards C) and 192.168.255.11/31 on C (towards A), A and C can't ping each other using those addresses. This is because A will announce 192.168.255.10/32 throughout the area and thus "overriding" the 192.168.255.10/31 route on C (traffic will would be sent to either B or D, and not directly to A).
What would be the cleanest solution for this?
FTR, the solution I'm currently testing with is using:
ip address add 192.168.255.10 peer 192.168.255.11 dev eth1
instead of:
ip address add 192.168.255.10/31 dev eth1
Seems to work fine so far, but suggestions/comments/etc are still more than welcome.
Forgot to mention something in my previous follow-up: the downside of the alternative mentioned above is that now 192.168.255.10 and 192.168.255.11 don't show up in the routing tables of the other nodes. Which, without applying other "fixes" would break traffic originating from those nodes using those IP addresses, including for instance traceroutes. Regards, Ruben Laban