Cabletron Systems FRM User Manual - page 146
9-22
Frame Relay Module 4. 0 User G uide, Rev 01
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 interface in the FRM and the remote device
is attached via a Token Ring, or vice versa, this MAC address will be "bit-swapped"
internally, because of the differences in frame formatting between 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 digit as specified in the following table. This reverses the binary bits
of each digit. For example,
7
(
0111
binary) becomes
E
(
1110
binary).
Digit Convert to
Digit Convert to
Digit Convert to
Digit Convert to
0
0
4
2
8
1
C
3
1
8
5
A
9
9
D
B
2
4
6
6
A
5
E
7
3
C
7
E
B
D
F
F
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 host as the proper address (e.g.,
400010001088
) after being
translated.
Session Type
if Originated, means the FRM will initiate LLC2 sessions from the configured Host
MAC Address. If Terminated, the node will accept LLC2 sessions destined for the
host address.
In the examples shown in
Figure 9-1
(on page 9-2), LLC2 hosts must be configured in
the FRM databases as follows:
●
Example 1: One record in FRM 2 for the host, with
Session Type
=
Terminated
.
●
Example 2: One record in FRM 1 for the host, with
Session Type
=
Originated
,
one record in FRM 2 for the host, with
Session Type
=
Terminated
.
●
Example 3: Two records in the FRM for the host, one with
Session Type
=
Originated
, the other
Terminated
.
●
Example 4: One record in the FRM for the host, with
Session Type
=
Originated
.