The Current Setup consists of a virtual router managing the VLANS 201, 401, 601 and routing traffic between the VLANs and the external network. Device A is connected to the virtual router via a switch.
Switch Configuation
VLAN 201
- Tagged Port: 1
VLAN 401
- Tagged Port: 1
- Untagged Ports: 2
VLAN 601
- Tagged Ports: 1
- Untagged Ports: 3
Devices Connected to the Switch
Port 1 -> Virtual Router
Port 2 -> Device A
Port 3 -> Device A
Note: The virtual router is a bare metal system running Ubuntu 22.04 server.
Netplan for the virtual router
network:
version: 2
renderer: networkd
ethernets:
eno1:
addresses:
- 10.1.1.12/24
routes:
- to: 0.0.0.0
via: 10.1.1.251
metric: 100
nameservers:
addresses:
- 10.1.1.23
- 10.1.1.22
enx7cc2c6436994:
dhcp4: false
mtu: 1550
addresses:
- 10.2.1.1/16
routes:
- to: 0.0.0.0
via: 10.4.1.251
metric: 100
nameservers:
addresses:
- 10.2.1.1
vlans:
vlan.401:
id: 401
dhcp4: false
mtu: 1550
addresses:
- 10.4.1.1/16
routes:
- to: 0.0.0.0
via: 10.4.1.1
metric: 100
link: enx7cc2c6436994
vlan.601:
id: 601
dhcp4: false
mtu: 1550
addresses:
- 10.6.1.1/16
routes:
- to: 0.0.0.0
via: 10.6.1.1
metric: 100
link: enx7cc2c6436994
DHCP configuration for the Virtual Router Router
option domain-name-servers 10.4.1.23, 10.4.1.22, 8.8.8.8, 8.8.4.4;
default-lease-time 600;
max-lease-time 7200;
ddns-update-style none;
subnet 10.2.0.0 netmask 255.255.0.0 {
option broadcast-address 10.2.255.255;
range 10.2.1.1 10.2.255.254;
option routers 10.2.1.1;
}
subnet 10.4.0.0 netmask 255.255.0.0 {
option broadcast-address 10.4.255.255;
range 10.4.1.1 10.4.1.254;
option routers 10.4.1.1;
}
subnet 10.6.0.0 netmask 255.255.0.0 {
option broadcast-address 10.6.255.255;
range 10.6.1.1 10.6.1.254;
option routers 10.6.1.1;
supersede mtu 1550
}
Netplan configuration on Device A
network:
version: 2
renderer: networkd
ethernets:
interface_A:
dhcp4: false
interface_B:
dhcp4: false
mtu: 1550
bridges:
cloudbr0:
addresses: [10.4.1.2/16]
routes:
- to: 0.0.0.0/0
via: 10.4.1.1
metric: 100
nameservers:
addresses: [8.8.8.8,8.8.4.4]
interfaces: [interface_A]
dhcp4: false
dhcp6: false
cloudbr1:
addresses: [10.6.1.2/16]
routes:
- to: 0.0.0.0/0
via: 10.6.1.1
metric: 1000
nameservers:
addresses: [8.8.8.8,8.8.4.4]
interfaces: [interface_B]
dhcp4: false
dhcp6: false
DHCP client configuration on Device A
option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;
send host-name = gethostname();
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
dhcp6.name-servers, dhcp6.domain-search, dhcp6.fqdn, dhcp6.sntp-servers,
netbios-name-servers, netbios-scope, interface-mtu,
rfc3442-classless-static-routes, ntp-servers;
Observed Behavior:
- I am able to ping Device A using 10.6.1.2 and 10.4.1.2. However I can only ssh into device using the 10.4.1.2 ip address. I am unable to ssh into device A using the 10.6.1.2 ip address.
- Changing mtu size of interface_B to 1500 seems to resolve the issue. However, I need to configure the mtu of interface_B to 1550