730
Spanning Tree Commands
port. In this way, the root guard enforces the position of the root bridge. In
MSTP scenario the port may be designated in one of the instances while
being alternate in the CIST, and so on. Root guard is a per port (not a per port
per instance command) configuration so all the MSTP instances this port
participates in should not be in root role.
STP BPDU Filtering
- STP BPDU filtering applies to all operational edge
ports. Edge Port in an operational state is supposed to be connected to hosts
that typically drop BPDUs. If an operational edge port receives a BPDU, it
immediately loses its operational status. In that case, if BPDU filtering is
enabled on this port then it drops the BPDUs received on this port.
STP BPDU Flooding
- STP BPDU flooding feature applies to the STP
disabled switch. To enable BPDU flooding on a port, STP should be disabled
on the switch administratively. When this feature is enabled on the switch, it
floods all the ports which have the BPDU flood feature enabled.
BPDU Storm Protection
- If STP BPDUs are received at a rate of 15 pps or
greater for 3 consecutive seconds on a port, the port will be diagnostically
disabled. A message of the following form is logged:
<188> MAY 04 09:45:23 10.10.10.10-1 DOT1S[276072720]: dot1s_ih.c(1587)
15855515 %% Diagnostically disabling interface 2/0/41
Use the
no shut
command to return the port to service.
Commands in this Chapter
This chapter explains the following commands:
clear spanning-tree
detected-protocols
spanning-tree
backbonefast
spanning-tree mode spanning-tree priority
exit (mst)
spanning-tree bpdu
flooding
spanning-tree mst
configuration
spanning-tree tcnguard
instance (mst)
spanning-tree
bpdu-protection
spanning-tree mst
cost
spanning-tree transmit
hold-count
name (mst)
spanning-tree cost spanning-tree mst
port-priority
spanning-tree
uplinkfast
revision (mst)
spanning-tree
disable
spanning-tree mst
priority
spanning-tree vlan
2CSNXXX_SWUM200.book Page 730 Tuesday, December 10, 2013 1:22 PM
Summary of Contents for Networking 2048
Page 82: ...Contents 82 ...
Page 216: ...216 Layer 2 Switching Commands ...
Page 248: ...248 AAA Commands ...
Page 256: ...256 Administrative Profiles Commands ...
Page 278: ...278 ACL Commands ...
Page 296: ...296 Address Table Commands ...
Page 344: ...344 DHCP Snooping Commands ...
Page 356: ...356 Dynamic ARP Inspection Commands 12 Enabled Disabled ...
Page 414: ...414 Ethernet Configuration Commands ...
Page 466: ...466 IGMP Snooping Commands ...
Page 476: ...476 IGMP Snooping Querier Commands ...
Page 508: ...508 IPv6 Access List Commands ...
Page 520: ...520 IPv6 MLD Snooping Commands ...
Page 528: ...528 IPv6 MLD Snooping Querier Commands ...
Page 550: ...550 Link Dependency Commands ...
Page 574: ...574 LLDP Commands ...
Page 606: ...606 Port Channel Commands ...
Page 626: ...626 MLAG ...
Page 634: ...634 Port Monitor Commands ...
Page 728: ...728 RADIUS Commands ...
Page 780: ...780 TACACS Commands ...
Page 790: ...790 UDLD Commands User Guidelines This command has no user guidelines ...
Page 840: ...840 Voice VLAN Commands ...
Page 878: ...878 802 1x Commands ...
Page 880: ...880 Data Center Technology Commands ...
Page 915: ...Priority Flow Control Commands 915 Te1 0 23 0 2 4 7 3 Active Te1 0 24 0 7 Inactive ...
Page 916: ...916 Priority Flow Control Commands ...
Page 918: ...918 Layer 3 Commands ...
Page 958: ...958 DHCP Server and Relay Agent Commands ...
Page 994: ...994 DHCPv6 Snooping Commands ...
Page 1002: ...1002 DVMRP Commands ...
Page 1006: ...1006 GMRP Commands ...
Page 1028: ...1028 IGMP Proxy Commands ...
Page 1080: ...1080 IP Routing Commands ...
Page 1131: ...IPv6 Routing Commands 1131 2 2001 2 12 msec 13 msec 12 msec 3 2001 2 14 msec 9 msec 11 msec ...
Page 1132: ...1132 IPv6 Routing Commands ...
Page 1136: ...1136 Loopback Interface Commands ...
Page 1165: ...Multicast Commands 1165 ...
Page 1166: ...1166 Multicast Commands ...
Page 1188: ...1188 IPv6 Multicast Commands ...
Page 1189: ...IPv6 Multicast Commands 1189 ...
Page 1190: ...1190 IPv6 Multicast Commands ...
Page 1276: ...1276 OSPF Commands console config router timers spf 20 30 ...
Page 1356: ...1356 Routing Information Protocol Commands ...
Page 1362: ...1362 Tunnel Interface Commands ...
Page 1384: ...1384 Virtual Router Redundancy Protocol Commands ...
Page 1386: ...1386 Utility Commands ...
Page 1426: ...1426 Captive Portal Commands ...
Page 1450: ...1450 Clock Commands ...
Page 1456: ...1456 Command Line Configuration Scripting Commands ...
Page 1476: ...1476 Configuration and Image File Commands ...
Page 1520: ...1520 Password Management Commands ...
Page 1564: ...1564 SDM Templates Commands ...
Page 1596: ...1596 Serviceability Tracing Packet Commands ...
Page 1608: ...1608 Sflow Commands ...
Page 1634: ...1634 SNMP Commands ...
Page 1668: ...1668 Syslog Commands ...
Page 1744: ...1744 System Management Commands ...
Page 1750: ...1750 Terminal Length Commands ...
Page 1762: ...1762 USB Flash Drive Commands ...
Page 1786: ...1786 Web Server Commands ...
Page 1821: ...W write 1474 write core 1593 ...
Page 1822: ...www dell com support dell com Printed in the U S A ...
Page 1823: ......