O'Reilly logo

Local Area High Speed Networks by Dr. Sidnie Feit

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Protocol Messages

Recall that frames containing Bridge PDUs are addressed to the multicast address X'01-80-C2-00-00-00. These frames contain the 3-byte Logical Link Control (LLC) header that is displayed in See figure 13.8. The LLC destination service access point (DSAP) and source service access point (SSAP) addresses both are X'42. The control field value, X'03, means "unnumbered information."

Figure 13.8. LLC header in BPDU frames.

Note

Logical Link Control headers, DSAPs, SSAPs, and control fields were discussed in Chapter 4, "The Classical Ethernet CSMA/CD Mac Protocol," in the section called "LSAPs."

The first 2 bytes of a BPDU ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required