Timeout

Test suite to validate DHCP client timeout and retry behavior.

The ISC DHCP client has specific timeout and retry behavior: - Sends DHCPDISCOVER with exponential backoff (10s → 20s → 40s → 120s) - Times out after 60 seconds if no DHCPOFFER received - Retries after 30 seconds (OSDx configuration) - Loops indefinitely until server responds

This test suite verifies: - Client properly times out when no server is available - Client recovers when server becomes available - Fallback IP is applied when configured and DHCP fails

Note: These tests are intentionally slow due to DHCP timeout values.

Test Client Timeout Without Server

Description

This scenario verifies that the DHCP client properly handles the case when no DHCP server is available on the network.

Expected behavior: - Client sends DHCPDISCOVER packets - Client times out after ~60 seconds - Client does NOT obtain an IP address - Client continues retrying (loop)

Note: This test waits 70 seconds to ensure timeout occurs.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 address 10.96.0.1/24
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 address dhcp
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Run command interfaces ethernet eth0 show at DUT1 and expect this output:

Test Client Recovery After Server Starts

Description

This scenario verifies that the DHCP client successfully obtains an IP address when the server becomes available after the client has already started requesting.

Expected behavior: - Client starts without server, times out - Server is started during client retry phase - Client successfully obtains IP from server

Note: This test waits for initial timeout then starts server.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 address 10.96.0.1/24
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 address dhcp
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Run command interfaces ethernet eth0 show at DUT1 and expect this output:

Step 4: Modify the following configuration lines in DUT0 :

set service dhcp-server shared-network dhcp subnet 10.96.0.0/24 start 10.96.0.5 stop 10.96.0.10

Step 5: Run command interfaces ethernet eth0 show at DUT1 and check if output contains the following tokens:

10.96.0.

Step 6: Run command service dhcp-server show leases at DUT0 and check if output contains the following tokens:

10.96.0.

Test Client Retry After Timeout

Description

This scenario verifies that the DHCP client continues to retry after timeout, demonstrating the infinite retry loop.

Expected behavior: - Client times out at 60s - Client retries after 30s (OSDx retry interval) - Second retry cycle begins

We verify by capturing DHCP traffic during retry phase.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 address 10.96.0.1/24
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 address dhcp
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Run command traffic dump monitor detail interface eth0 filter "port 67 or port 68" packets 5 at DUT0.

Test Fallback IP Applied On Timeout

Description

This scenario verifies that when a fallback IP is configured and DHCP times out, the fallback IP is applied to the interface.

This is a single-DUT test (DUT0 only) - no server is needed.

Configuration: - set interfaces ethernet eth0 address dhcp - set interfaces ethernet eth0 dhcp client fallback 10.96.0.99/24

Expected behavior: - Client sends DHCPDISCOVER - No server responds, timeout occurs - Fallback IP (10.96.0.99/24) is applied

Note: This tests the fallback mechanism on initial timeout.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 address dhcp
set interfaces ethernet eth0 dhcp client fallback 10.96.0.99/24
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Run command interfaces ethernet eth0 show at DUT0 and check if output contains the following tokens:

10.96.0.99