9-22 Smart Switch 1800 4. 0 User Guide , Rev 0 1
Host MAC Address
is the MAC address of the host or workstation to which an SNA/LLC2 device needs
to connect.
If the host will be attached via an Ethernet inte rface in the SmartSwit ch and the re mote
device is attached via a Token Ring, or vice versa, this MAC address will be "bit-
swapped" internally, be cause of the diff erences in frame forma tting bet ween Ethernet
and Token Ring. In this case, the address must be "bit-swapped" again, so the remote
device will receive an address in the correct format.
Bit swapping is done by reversing the order of the bits (digits) within each byte (pair
of digits) of the hexadecimal address, while leaving the sequence of the bytes
unchanged.
For example, to bit-swap the hex address 400010001088:
1. Break the address into pairs of digits:| 40 | 00 | 10 | 00 | 10 | 88 |
2. Reverse the digits within each pair: | 04 | 00 | 01 | 00 | 01 | 88 |
3. Replace each dig it as specified in the fo llowin g tab le. T his rev erses t he bina ry bits
of each digit. For example, 7 (0111 binary) becomes E (1110 binary).
Digit Convert to Digit Convert to Digit Convert to Digit Conve rt to
00 42 81C3
18 5A 99DB
24 66 A5 E7
3C 7E BD FF
Using the example,| 04 | 00| 01| 00 | 01 | 88 |
converts to: | 02| 00 | 08 | 00 | 08| 11 |
4. Enter the bit swapped value (e.g., 020008000811) as the Host MAC Address. This
value will arrive at the h ost as the proper addre ss (e.g., 400010001088) after being
translated.
Session Type
if Originated, means the SmartSwitch 1800 will initiate LLC2 sessions from the con-
figured Host MAC Address. If Terminated, the n ode will accept LLC2 sessions des-
tined for the host address.
In the examples shown in Fi gure 9-1 (on page 9-3), LL C 2 hos t s mus t be c o nfigure d in
the SmartSwitch databases as follows:
●Example 1: One record in SmartSwitch 2 for the host, with Session Type =
Terminated.
●Example 2: One record in SmartSwitch 1 for the host, with Session Type = Orig-
inated, one record in SmartSwitch 2 for the host, with Session Type =
Terminated.
●Example 3: Two records in the SmartSwitch for the host, one with Session
Type = Originated, the other Terminated.
●Example 4: One record in the SmartSwitch for the host, with Session Type =
Originated.