VLAN Trunk Protocol (VTP)
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The summary advertisements can contain the following information:
Management domain name The switch that receives this advertisement
must have the name that's in this field or the update is ignored.
Configuration revision number Receiving switches use this to identify
whether the update is newer than the one they have in their database.
Updater identity The name of the switch from which the update is sent.
Updater timestamp May or may not be used.
MD5Digest The key sent with update when a password is assigned to
the domain. If the key doesn't match, the update is ignored.
The subset advertisements contain specific information about a VLAN.
Once an administrator adds, deletes, or renames a VLAN, the switches are
notified that they are about to receive a VLAN update on their trunk links
via the VLAN-info field 1. Figure 3.6 shows the VTP subset advertisement
inside this field.
F I G U R E 3 . 6
Subset advertisement
The following list includes some of the information that is advertised and
distributed in the VLAN-info field 1:
VLAN ID Either ISL or 802.1q
802.10 SAID field that identifies the VLAN ID in FDDI
VTP VTP domain name and revision number
MTU Maximum transmission size for each VLAN
V-info-len Status
VLAN-
type
MgmtD
Len
VLAN-ID
MTU Size
802.10 Index
VLAN Name
RSUD
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