Vyos dhcp server setup - client is not able to route traffic

General questions
1

Hi,

I’m fairly new to Vyos, I have setup a few times now the below setup:

eth0 - external interface, address via dhcp
eth1 - internal interface, dhcp server running, handling clients that are also connected on this interface (isolated network).

I have set this up a few times now as a kvm vm and then another vm on the internal interface gains an ip via dhcp from the configured range and nat setup, packets can then route as required.

On one particular laptop that I wish to use this same setup does not work, the vm gains an ip via dhcp, ip route command shows the required gateway, however packets do not route back.

Does anybody have any thoughts that may assist in this matter.

Many thanks

2

Do you see the packets being actuallt sent on your outgoing interface?

3

Hi hagbard,

Thanks for quick response, apologies for the delay in responding.

On the internal interface if I ping 8.8.8.8 from the vm that has gained an ip via dhcp I see:

on vm that has gained an ip:

PING 8.8.8.8 (8.8.8.8): 56 data bytes

On vyos router:

vyos@vyos:~s monitor traffic interface eth1
listening on eth1, link-type EN10MB (Ethernet), capture size 262144 bytes
08:49:55.770065 IP my-laptop-host-name > dns.google: ICMP ehco request, id 42769, seq 8, length 64
08:49:56.012407 STP 802.1d, Config, Flags [none], bridge 8000.52:54:00:63:9f:e5.8002, length 43

This is then repeated however many times until I cancel it

If I do the same command on the outbound interface eth0 I can see:

09:02:57.064008 IP my-laptop-host-name > dns.google: ICMP echo request , id 43025, seq 21, length 64

I hope that answers the question?

Many thanks

4

Your traffic gets routed asynchronly. Your request leave at eth1 and comes back in on eth0. Do you have any fw rules in place? what is your routing table look like?

5

Hi,

No fw rules that I am aware of, I will look into the routing table and advise asap.

Thanks again