At 10:37 AM 1/11/2002 +0200, [EMAIL PROTECTED] wrote: >To explain how it works: >A=Host A >B=Host B >Bmac=MAC address of Host B >S=Sonicwall >Sa=Sonicwall's network interface on Host A segment >Sb=Soniwalls's network interface on Host B segment > >Subnet is same for both clients. Let's say it's 192.168.1.0/24 > >A---Sa|S|Sb----B > >So when A wants to connect B, what happens: >1. A will send ARP request to get host B MAC address
If the SonicWall were a bridge, yes this is what would happen. However it is NOT what does happen. What actually happens is that A sends an ARP to get the MAC address of Sa. In other words, A "knows" about Sa and talk to it directly. Hence the IP datagram that A sends will have the destination IP address of B but the destination MAC address of Sa. Hence, S is a router. >2. Sonicwall will see the request in interface Sa and respond (it >probably sends ARP to host B and then uses that MAC) You are describing what is known as Proxy ARP. It was quite popular about 15 years ago. It is not used anymore. And it does not happen with a SonicWall. >3. A will send syn to Bmac (which will actually go to Sonicwall >interface Sa) >4. Sonicwall will check the syn against it's Security policy and in this >case it's allowed #3 and #4 are firewall functions. They are not relevant to the determination of whether the SonicWall is a bridge or a router. At 10:56 AM 1/11/2002 +0200, [EMAIL PROTECTED] wrote: >There are some additional benefits of Transparent Bridge comparing to >routing firewall: In effect you are re-inventing some of the arguments that were popular during debates about routers-vs-bridges, shortly after bridging was invented in the late 1980s. As with any interesting debate, the list of positives also carries a list of negatives. d/ ps. I notice that this exchange has reduced to just the two of us, and that it has gone on for awhile. Unless others show further interest in the topic, I think we have explored it enough. ---------- Dave Crocker <mailto:[EMAIL PROTECTED]> Brandenburg InternetWorking <http://www.brandenburg.com> tel +1.408.246.8253; fax +1.408.273.6464 _______________________________________________ Firewalls mailing list [EMAIL PROTECTED] http://lists.gnac.net/mailman/listinfo/firewalls
