BAREMETAL : Docker breaks EVE-NG networking

[lemonajnkur]

I have dedicated Dell Workstation with EVE-NG over Ubuntu.

I installed Docker(to learn it) today but noticed, it would break the networking of all routers/VM's inside my LAB.

Router#ping 1.1.1.1 repeat 10000

Type escape sequence to abort.
Sending 10000, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!..................................
......................................................................
......................................................................
......................................................................
.........................

I was able to diagnose it as the ping's on router works for 3-5 minutes after server reboot.
However, I noticed ping stops when 'docker' interfaces start showing up in ífconfig'.

root@eve-ng-sep2021:~# ifconfig | grep Link
docker0 Link encap:Ethernet HWaddr 02:42:38:0c:d9:21
inet6 addr: fe80::42:38ff:fe0c:d921/64 Scope:Link
eth0 Link encap:Ethernet HWaddr 98:90:96:c3:1f:91
inet6 addr: fe80::9a90:96ff:fec3:1f91/64 Scope:Link
lo Link encap:Local Loopback
pnet0 Link encap:Ethernet HWaddr 12:65:2b:a4:7b:68
inet6 addr: fe80::9a90:96ff:fec3:1f91/64 Scope:Link
pnet1 Link encap:Ethernet HWaddr ae:68:49:a1:5b:96
inet6 addr: fe80::ac68:49ff:fea1:5b96/64 Scope:Link
pnet2 Link encap:Ethernet HWaddr ea:6f:77:e4:05:ba
inet6 addr: fe80::e86f:77ff:fee4:5ba/64 Scope:Link
veth5e8e4fa Link encap:Ethernet HWaddr 46:8b:38:2d:cc:44
inet6 addr: fe80::448b:38ff:fe2d:cc44/64 Scope:Link
vethd419506 Link encap:Ethernet HWaddr 2a:fa:79:17:56:ad
inet6 addr: fe80::28fa:79ff:fe17:56ad/64 Scope:Link
vnet0_2 Link encap:Ethernet HWaddr 02:5b:34:eb:b9:d6
vnet0_11 Link encap:Ethernet HWaddr 6a:72:0a:3e:1c:cf
vunl0_10_0 Link encap:Ethernet HWaddr 6a:72:0a:3e:1c:cf
vunl0_7_0 Link encap:Ethernet HWaddr 02:5b:34:eb:b9:d6

- similar looking interfaces removed from output above for easy reading

I kept checking ífconfig' to confirm my doubt and I was right., it's something to do with docker. Probably when docker process started after reboot it changes something with networking of EVE-NG VM's

I'm no expert on Linux so I think, I need to tweak few settings in networking or somewhere to fix it?