Symptom

1. Create 2 default routes via IF1 and IF2. 2. Configure Cloudexpress Probe via IF1. 3. DNS Packets of Cloudexpress probe is exiting via IF2 but it should go via IF1 (as this is the preferred interface as per the cloudexpress probe config) If the IF1 is not pointing to internet, the DNS request of the Cloudexpress will be lost and this will lead to 100% loss in cloudexpress probes.

Conditions

Only if there are more than one default route (i.e for a given route if there are more than one valid exit interface)

Workaround

For the cloudexpress to work, the nameservers should be configured under 'ip name-server' and to avoid hitting this issue configure a specific route to the DNS IPs (configured under ip name-server) via the probe interface. This will ensure that the DNS packets exit via the probe interface (which will be an internet reachable interface). If there are more than one internet reachable interface and if probes are configured on both the interfaces, then user should configure the specific route to DNS IP via both the configured interfaces.

Further Problem Description