Good Afternoon All,
Looking for a little advice, we are just starting on our journey to VLAN segregate a current /16 flat network however we are running into a few roadblocks when trying to access anything externally from the new subnets.
We have adopted one of our HP 5412z's as our core (172.16.8.80), which has our new VLAN interfaces configured (moving away from 172.16.0.0 to mostly 10.10.0.0/24 subnets), as well as IP Routing enabled and a default route to our Smoothwall box of 0.0.0.0 0.0.0.0 172.16.0.10.
INT1 on Smoothwall is 172.16.0.10, with its gateway as a Juniper ISP Managed Firewall at 172.16.0.11. Within Smoothwall we have also configured the 'subnets' page to reflect the new ranges with their gateway as the Core switch on 172.16.8.80.
So far everything is working as intended with our internal network, can ping between subnets and to Smoothwall and the DC's, however the new subnets do not have any internet access at all, or DNS resolution. Further investigation of this has lead me to discover from our two DC's, DC1 has its default gateway set to the ISP Managed Firewall on 172.16.0.11, and DC2 has its default gateway set to Smoothwall on 172.16.0.10. Having changed these to the new Core Switch on 172.16.8.80 or Smoothwall on 172.16.0.10 leads to a total loss of connectivity on our DC's also which makes me believe we may have a routing configuration problem.
Our topology documented is here if it helps:
Any tips or advice on where I could look and troubleshoot would be hugely helpful and appreciated.