Question

IP Forwarding trouble - hosts can't go to internet

  • 12 February 2021
  • 2 replies
  • 41 views

Hi,

i tried to configure a extreme switch with two vlans:

vlan500- ISP - 10.0.0.20/29

vlan3572 - local users - 10.83.72.1/24

My default route to this communication is ISP (10.0.0.17). 

I can ping the 8.8.8.8 with source 10.0.0.20 (ISP) that i can see request/reply on my firewall logs but when i try with source 10.83.72.1 looks link the traffic move to internet but not answer back. And when i try with a notebook on vlan 3572 untagged on port 2:40 i can’t ping 8.8.8.8 and no logs on my firewall.

A friend told me that if i configure ip fowarding will solve my problem.

Anyone can tell me if this is right?

Regards,

Rodrigo


2 replies

Userlevel 6
Badge

Hi Rodrigo,

 

What switch family do you mean, is it ExtremeXOS software? If so, ‘enable ip forwarding’ is responsible for making your switch working on L3 like a router. Then, if it gets 8.8.8.8 echo request from vlan 3572, it will lookup its route table and forward to the next-hop. But, does the next-hop router know how to reach back to 10.83.72.0/24?

These are two things I’d double check for troubleshooting this. Please let us know if any of those worked for you.

 

Hope that helps,

Tomasz

Hi Tomasz,

thanks for your help and answer your questions.

First, the next-hop knows how to reach 10.83.72.0/24 because the switch has an ip with the same network from and i have the same configuration on another site but with a switch Huawei.

Next week i try this configuration and send back a message here.

Thanks again

Rodrigo

Reply