Load-Balancing Client/Server on same subnet
Hi all, I’m working on a customer's issue where the VIP, pool members and clients are all on the same subnet (lets say 10.1.1.0/24) and no SNAT on the VIP. I'm seeing an issue related to ARP that only affects one of the 6 servers. All servers are Dell. Client – 10.1.1.12 VIP – 10.1.1.4:25 Member Servers 1-6 – 10.1.1.5-19:25 I would expect the flow to go from Client to VIP to Member Server directly back to the client and break communications, but 5 out of 6 servers actually go right back through the F5 and work fine. If you look at the ARP cache on these boxes, it only has one or two entries pointing to the F5 - none for the client (10.1.1.12). The server that does not work does have an ARP entry for the client IP and the return traffic goes directly back to the client. No static ARP setup on the working servers as far as I can tell. Nothing in the F5 configs about mac spoofing/masquerading. Creating a static arp entry for the client IP to point to the F5 mac on the server that's not working fixes this server. I'm a little confused on any of the servers are working at all. Any insight into how this is supposed to work without SNAT would be extremely helpful. Thanks in advance! Chintan
MAC Masquerading for VIPs on VLANs on the same Layer2 Network
Hello Guys, we've got a customer with a grown and old network design which causes some headache and i am evaluating possible solutions. During a manually triggered failover for a hotfix installation some of the 180 VS didn't accept traffic. I guess the switch thought that the sudden amount of GARPs might be an attack and dropped some advertisements. After around 15min everything was working fine again. So to prevent something like this in the future i had the idea of using mac masquerading on the traffic group, but i am uncertain on the possible pro and cons. The BIG-IP has two vlans configured, internal and external. Each vlan is on a dedicated physical interface (1.1 and 1.3) and each is untagged, so basicly both vlans are on the same layer2 network. What will happens once mac masquerading would be enabled? From my understanding each IP associated with an VS, each floating self ip will have the same MAC address in the traffic group, which seems like an bad idea for me in the given scenario. I'd appreciate your input on this. Best regards David