Symptom

After reloading device is sending ICMP Type 3 Code 13 when 'no ip unreachables is configured on the interface. But then reapplying 'ip unreachables & no ip unreachables', router will send ICMP Type 3 Code 13 again.

Conditions

After reloading with/upgrading to the version later than 16.3.x, like 16.6.x 16.9.x and 16.12.x, 'no ip unreachables' will not work on ASR platform with one of below configurations. CSR have been confirmed that it works well after reloading/upgrading without reapplying. Configuration 1: router#show running-config interface Gig0/0/0 ! interface TenGigabitEthernet0/1/0 ...... no ip redirects no ip unreachables ...... end Configuration 2: Router#show running-config interface null 0 Building configuration... Current configuration : 43 bytes ! interface Null0 no ip unreachables end Router#

Workaround

Workaroud1: After reapplying as below it will work again. Router(config)#interface GigabitEthernet 0/0/0 Router(config-if)#ip unreachables Router(config-if)#no ip unreachables Workaround2: Don't configure 'no ip redirects' and 'no ip unreachables' at the same time under hardware interface.

Further Problem Description