BROCADE IP PRIMER

Chapter 15: Server Load Balancing (SLB)10. I'm using DSR. When I perform a “show server real”, I don't see any “Rxpkts”or “Rx-octets”, but I see lots of “Tx-pkts” and “Tx-octets.” Why?a. You forgot to configure a loopback on your real serverb. You didn't enable DSR in the real server configc. Your real server port is not actived. In DSR, the ServerIron never sees return traffic; these counters areuselessAnswers to Review Questions1. d. This is where you would use a shadow port. You are binding to a differentport on the real server, but you are binding the same port (HTTP, inthis case) on the virtual server. Just make sure you've got “no port httptranslate” in your virtual server config.2. a. Round-robin just picks the next one in line. If a server is down, it skipsit, but other than that, it blindly sends to the next server.3. b. The ServerIrons continue their hello messages across the data linkuntil the sync link is restored. If the data link between the ServerIronsgoes down as well, answer C would be correct.4. b. All servers (including remote) are considered primary, unless they arespecifically configured as “backup.”5. a. “sym-priority” is the magic word. This is added to the virtual server configon all participating ServerIrons.6. c. It is 4.7. b. DSR is unique to the virtual server port, so it is enabled in the virtualserver config. The correct commands in this case are “port http dsr.”8. c. Tricky one. Most people think of the “port http url” command availablefor HTTP. But for all well-known Layer 7 protocols, you can use the keyword“keepalive” (e.g., “port smtp keepalive”) to trigger their unique Layer 7health check.9. b. The ServerIron's source-ip. This is the whole reason Source NAT works.If you missed this question, review Chapter 3. When the ServerIronreceives the packet, it substitutes the source-ip address (that is most“local” to the real server) as the source IP of the packet (as well as substitutingthe IP of the real server as the destination IP).10. d. So many engineers (and their bosses) have required an explanation ofthis. DSR is unique in that it's the only solution where the ServerIron doesnot see all the traffic. Given that, certain predictors and statistics will notbehave necessarily as expected.354 Brocade IP Primer