3Com PathBuilder S200 Series Owner's Manual page 47

Figure 22. Server's Destination MAC Address Not on LAN AAA
3) After receiving no response on the local LAN, the PC uses Source Route
PC
Figure 23. All Route Explorer (ARE) Frame Searches the Network for
the Server
4) The TEST frame includes the following:
Bridging
T0008-16F
Configuring the PathBuilder S200 Series Switch for Bridging Operation
Frame
PC
?
LAN
PC AAA
?
PC
PC
? ?
Bridging (SRB) to find the path to the remote server. The PC can resend the
TEST frame indicating that the frame is to be bridged over all routes.
The PC resends an All Route Explorer (ARE) TEST frame via its SRB software
(Figure 23).
?
LAN
AAA
ARE Frame
• Destination Address is server's MAC Address.
• Routing Information Indicator bit (RII) is set to one. This bit is the most
significant bit in the source address, indicating this frame has a Routing
Information Field (RIF).
• Three bits in the Routing Information Field (RIF) indicate this is an ARE.
This instructs all bridges that encounter this frame to forward the frame to
their destination LANs. This form of broadcast ensures that at least one copy
of the frame arrives at the destination.
• Routing Information Field (RIF) shows the path (LAN number/Bridge
number, LAN number/Bridge number, etc.) that each ARE frame took on its
search between the source and the destination.
PB S200
PB S200
43
Release 5.2M