[j-nsp] Route Precedence

[Chris]

Hi all,

I have a pair of EX4200's which are running iBGP to a pair of J6350's.

I am seeing some strange behaviour with the routing on them. The
EX4200's have a few different VLANs setup:

vlan 50 - Used to connect to a J6350
vlan 100 - The VLAN the devices I am trying to reach are on

The devices on vlan 100 are on the 10.10.10.0/24 range, with the
EX4200's being the gateway for that network (it has been assigned
10.10.10.254). The problem I am seeing is from the EX4200's I can reach
any device in that network fine. From the J6350's I can reach SOME
devices but not others. I have not been able to find a pattern for this
- an example device I have plugged in is a Dell blade chassis. It has a
management controller that sits on 10.10.10.100 which I can get to from
both the EX4200's and the J6350's. Each blade in the chassis is also
assigned an IP for management through the same controller, in this case
10.10.10.101-117. I can't reach the individual blade management IP's
from the J6350's yet from the EX4200's I can reach them fine. It has me
a bit confused as it uses the same port on the EX4200's.

For the below examples, here is the IP addressing (these are obviously
not real):
99.99.99.240/30 - acc-core vlan50 (99.99.99.241) and acc-bdr1 ge-0/0/0
(99.99.99.242)
99.99.99.253 - acc-core lo0

On the J6350's the route for 10.10.10.0/24 is learnt via iBGP:

root at acc-bdr1> show route 10.10.10.0

inet.0: 363930 destinations, 363932 routes (170427 active, 0 holddown,
193504 hidden)
+ = Active Route, - = Last Active, * = Both

10.10.10.0/24      *[BGP/170] 00:49:35, localpref 100, from 99.99.99.253
                      AS path: I
                    > to 99.99.99.241 via ge-0/0/0.0

That route does seem to work, if I ping any IP in 10.10.10.0/24 (even
the 'non-working' IPs) and run a tcpdump on the J6350 I can see the
traffic heading out to the EX4200's.

As a test, I added a static route for 10.10.10.101/32 with a next hop of
10.10.10.254 on the J6350. This doesn't show in the routing table on the
J6350:

root at acc-bdr1> show configuration routing-options static route
10.10.10.101/32
next-hop 10.10.10.254;

root at acc-bdr1> show route 10.10.10.101

inet.0: 363933 destinations, 363935 routes (170429 active, 0 holddown,
193505 hidden)
+ = Active Route, - = Last Active, * = Both

10.10.10.0/24      *[BGP/170] 00:54:12, localpref 100, from 99.99.99.253
                      AS path: I
                    > to 99.99.99.241 via ge-0/0/0.0

On the EX4200 the route is there correctly:
root at acc-core> show route 10.10.10.101

inet.0: 16384 destinations, 16384 routes (16384 active, 0 holddown, 0
hidden)
Restart Complete
+ = Active Route, - = Last Active, * = Both

10.10.10.0/24      *[Direct/0] 00:55:58
                    > via vlan.100

After the route was added, the EX4200 had the power cut and restored and
I could magically ping 10.10.10.101 from the J6350 with no other config
changes. The power was cut again, and I then lost the ability to ping it
from the J6350, but I could still ping it from the EX4200. I have no
idea why this is so I am a bit confused.

The J6350 has no filters in place currently, it is running the router
config too with the security features disabled.

Is there anything obvious I'm missing?

Thanks