HP 200 Series Services And Applications page 94

Bridging Service
Source-Routing Bridging
When the destination is not found in the address table or when the
destination is a multicast address, the frame is converted to an explorer
frame (single route explorer). This frame is then forwarded to all SRB circuit
groups configured for TRNSB.
As is shown in figures 29 and 30, both 802.3 and Ethernet formats are sup-
ported. Ethernet version 2 frames are limited to what is often called the IBM
PC/RT format, which is a proprietary encapsulation of 802.2 frames in an
Ethernet type header. Which of the 802.3 and Ethernet formats is used is
indicated by configuration of the router. Either one can be configured as the
default conversion format, and a list of station addresses that use the other
format can be specified. Most end nodes use the 802.3 format.
Limitations
TRNSB does not support protocols that can be routed.
TRNSB does not operate with looped topologies that mix SRB and
TB. That is, TRNSB operates in looped topologies only when the
links in the loops are either all SRB or TB, but not a combination of
both.
TRNSB does not support either the hop-count reduction or the group
LAN ID function described in the following sections of this chapter.
The HP Remote Bridge will not perform the TRNSB translation,
but can be connected across a transparent-bridging WAN link to an
HP router that does perform the translation—an HP Router TR or
HP Router 650 with a token ring interface module.
The load-balancing function for bridging circuit groups does not
support translational bridging.
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