On 2009-12-15, Doran Mori <dhm...@gmail.com> wrote:
> It looks like the last road block in my router project is going to be
> similar to Vladimir Kirillov's problem. In my case I'm having a
> downed link layer host route take precedence over an up ospf /32 route
So it seems that any host routes, even RTP_DOWN, take priority over
higher priority net routes for the same address.
This explains a little trouble I've been having when I restart ospfd
(which I do a bit more often than is good for me, but haven't been able
to put my finger on exactly why I have to...)
My bgp routers run sessions between loopbacks on lo1 which are advertised
into ospf. My defaults are localhost -reject routes. A pretty typical setup
for a network with multiple links between routers.
If I stop and restart ospfd on router X, typically the bgp sessions
go down, and if I go to the other routers I see dynamic host routes
directing X's traffic towards 127.0.0.1;
Y# route -n get X
route to: aa.bb.cc.9
destination: aa.bb.cc.9
gateway: 127.0.0.1
interface: lo0
if address: 127.0.0.1
priority: 56 (default)
flags: <UP,GATEWAY,HOST,DYNAMIC,DONE>
use mtu expire
41060 33160L 522
Y# netstat -rnfinet | grep aa.bb.cc.9
aa.bb.cc.9 127.0.0.1 UGHD 2 41188 33160 L 56 lo0
aa.bb.cc.9/32 aa.bb.cc.244 UGP 0 0 - 32 vlan2244
aa.bb.cc.9/32 aa.bb.cc.243 UGP 0 0 - 32 vlan2244
and I have to route delete aa.bb.cc.9 to get things flowing again.
I'm not quite sure why it's RTF_DYNAMIC, ICMP redirects are off and
I haven't spotted where other than ICMP redirects that sets this,
so I'm not entirely sure where this entry has come from.
All pretty recent code, Y is running Nov 11th, X running Dec 14th,
this isn't new though, I have just managed to get past enough other
problems that I can see it a bit more clearly..;-)
