2. Isolate any ne w modules that have logical ports on the ring (logical is a port
which cannot be disabled such as TRMM or bridge).
3. Ifthe source or destination address in the packet is external to the hub, wait
for up to 5 seconds to check if the beaconing can be disabled externally.
4. Ifthe source or destination address in the packet is external to the hub,
disable all external trunks.
5. Disable any enabled ports on fiber repeater (these ports may show as
external if both sets of trunks on the fiber repeater are enabled).
6. Disable any enabled ports that are between the source and destination
addresses contained in the beaconing packet.
7. Isolate any modules that are between the source and destination addresses
contained in the beaconing packet.
8. Ifboth addresses are internal to the hub and there are enabled trunks in
between, disable the trunks.
9. Disable port corresponding to destination address.
10. If the destination in beaconing packet is external, shut down all external
trunks *.
11. Disable the port corresponding to the source address.
12. If the source of beaconing packet is external, shut down all external trunks *.
13. If any MAC-less devices are present on the ring, disable the
ports corresponding to these devices.
14. Disable external trunks again to test for condition where beaconing was fixed
temporarily externally *.
15. Isolate modules one at a time until beaconing is detected to be gone. If
beaconing goes away put module back on network and disable ports on that
module until beaconing goes away. When beaconing ends, the correct port
has been found.
16. Isolate the TRMM if all else fails.
* When external trunks are disabled and the disabling fixes the beaconing
problem perform the following:
•Re-enable all trunks with external beacon recovery non_exists.
•If no beaconing, re-enable trunks with external beacon recovery exists.
•If beaconing now detected, shut down all trunks with external beacon
recovery exists. Re-enable trunks one at a time until source of beaconing is
detected and then disable that trunk.
•If beaconing when trunks with external beacon recovery non_exists are
re-enabled, then disable all these trunks. Re-enable trunks with external
beacon recovery exists.
In case the NAUN of the station issuing Beacon MAC frame is the TRMM itself,
the TRMM will take itself off the ring to perform the self-test as any other station.
If there is no problem with TRMM, it re-enters the ring. However, if a problem is
found in TRMM, it will stay off the ring and isolated. In this case the beacon
problem is resolved, but the ring is now operating without TRMM and if another
station causes a beacon condition that requires TRMM intervention the operation
of the ring will be disrupted.
Chapter 8. 8260 Token-Ring Support 153