[fast-reboot]: Fix IP range overlapping

[nazariig]

Signed-off-by: Nazarii Hnydyn [email protected]

Description of PR

Summary:

Fast-Reboot test uses random generator to pick up an arbitrary IP address from the default_ip_range subnet:
https://github.com/Azure/sonic-mgmt/blob/201811/ansible/roles/test/files/ptftests/advanced-reboot.py#L504
Sometimes it may overlap with the DUT VLAN IP subnet which will result in packet drops:

root@6aad39fed86f:~# ./run.sh
WARNING: No route found for IPv6 destination :: (no default route?)
advanced-reboot.ReloadTest ... 2020-04-29 16:04:44 : Converted addresses VMs: ['10.9.78.183', '10.9.78.182', '10.9.78.181', '10.9.78.180']
2020-04-29 16:04:44 : Test params:
2020-04-29 16:04:44 : DUT ssh: admin@sonic
2020-04-29 16:04:44 : DUT reboot limit in seconds: 0:00:30
2020-04-29 16:04:44 : DUT mac address: 7c:fe:90:f5:36:40
2020-04-29 16:04:44 : From server src addr: 192.168.1.214
2020-04-29 16:04:44 : From server src port: 15
2020-04-29 16:04:44 : From server dst addr: 192.168.7.69
2020-04-29 16:04:44 : From server dst ports: [28, 30, 29, 31]
2020-04-29 16:04:44 : From upper layer number of packets: 500
2020-04-29 16:04:44 : VMs: ['10.9.78.183','10.9.78.182','10.9.78.181','10.9.78.180']
2020-04-29 16:04:44 : Disabling arp_responder

DUT IP config:

root@sonic:/home/admin# show ip interfaces
Interface        IPv4 address/mask    Admin/Oper
---------------  -------------------  ------------
PortChannel0001  10.0.0.56/31         up/down
PortChannel0002  10.0.0.58/31         up/down
PortChannel0003  10.0.0.60/31         up/down
PortChannel0004  10.0.0.62/31         up/down
Vlan1000         192.168.0.1/21       up/down
docker0          240.127.1.1/24       up/down
eth0             10.9.74.46/24        up/up
lo               127.0.0.1/8          up/up
                 10.1.0.32/32

VLAN IP:

Address:   192.168.0.1           11000000.10101000.00000 000.00000001
Netmask:   255.255.248.0 = 21    11111111.11111111.11111 000.00000000
Wildcard:  0.0.7.255             00000000.00000000.00000 111.11111111
=>
Network:   192.168.0.0/21        11000000.10101000.00000 000.00000000 (Class C)
Broadcast: 192.168.7.255         11000000.10101000.00000 111.11111111
HostMin:   192.168.0.1           11000000.10101000.00000 000.00000001
HostMax:   192.168.7.254         11000000.10101000.00000 111.11111110
Hosts/Net: 2046                  (Private Internet)

FAST-REBOOT VLAN IP range (old):

Address:   192.168.0.0           11000000.10101000 .00000000.00000000
Netmask:   255.255.0.0 = 16      11111111.11111111 .00000000.00000000
Wildcard:  0.0.255.255           00000000.00000000 .11111111.11111111
=>
Network:   192.168.0.0/16        11000000.10101000 .00000000.00000000 (Class C)
Broadcast: 192.168.255.255       11000000.10101000 .11111111.11111111
HostMin:   192.168.0.1           11000000.10101000 .00000000.00000001
HostMax:   192.168.255.254       11000000.10101000 .11111111.11111110
Hosts/Net: 65534                 (Private Internet)

FAST-REBOOT VLAN IP range (new):

Address:   192.168.100.0         11000000.10101000.01 100100.00000000
Netmask:   255.255.192.0 = 18    11111111.11111111.11 000000.00000000
Wildcard:  0.0.63.255            00000000.00000000.00 111111.11111111
=>
Network:   192.168.64.0/18       11000000.10101000.01 000000.00000000 (Class C)
Broadcast: 192.168.127.255       11000000.10101000.01 111111.11111111
HostMin:   192.168.64.1          11000000.10101000.01 000000.00000001
HostMax:   192.168.127.254       11000000.10101000.01 111111.11111110
Hosts/Net: 16382                 (Private Internet)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Approach

How did you do it?

• Fixed default_ip_range subnet

How did you verify/test it?

1. Run fast-reboot test

Any platform specific information?

• N/A

Supported testbed topology if it's a new test case?

• N/A

Documentation

• N/A

[lguohan]

can you change the fast-reboot script in pytest as well? @tamer-dev, is there a same problem for the pytest version?

[nazariig]

@lguohan same fix for master #1637

[tahmed-dev]

@lguohan yes, the pytest reboot test has prefix lent of 16. @nazariig can you please modify this file as well:

https://github.com/Azure/sonic-mgmt/blob/master/tests/common/fixtures/advanced_reboot.py#L129